Life and Times of Astrogirl

Thesis finally has a title and Abstract

2009-07-30T08:46:00.001+10:00

Well, at least it is a start, have been fortunate that Brad was down observing at the AAT as it meant we were able to catchup on a plan of where I ma actually going with it all. Of course it was also cool that I got to spend most of Friday ight and several hours last night in the AAT control room.

Space Shuttle Update

2009-07-30T08:42:00.002+10:00

The Space shuttle Endeavour undocked Wednesday from the International Space Station at 9:26 am AEST. After completing a fly-around of the space station, Endeavour performed a manoeuvere to separate itself from the station. Shuttle astronauts will inspect next Endeavour’s heat shield one more time today as they begin to set their sights on an early saturday mornign AEST time landing. On Sunday, Discovery was rolled to the VAB to be readied for the next Shuttle Mission in August.

Space Shuttle Endeavour Launch Postponed Again

2009-07-14T09:46:00.002+10:00

Today's launch of the Space Shuttle Endeavour - STS 127 has been cancelled due to weather. This occurred about an hour ago at around 8.40 our time. The 16-day mission will feature five spacewalks and complete construction of the Japan Aerospace Exploration Agency's Kibo laboratory. Astronauts will attach a platform to the outside of the Japanese module that will allow experiments to be exposed to space.

The mission has been rescheduled for Thursday July 16th at 8.03 am Australian Time - which is 6.03pm Wednesday US EDT time. There were thunderstorms in the area and the crew were already inside the shuttle and the countdown had been stopped at the second of 2 hold positions at T-9minutes this was a planned 45 minute hold and it was 40 minutes into this hold and about 11 minutes from the preferred lift off time that it was cancelled.

In Melbourne for ASA Conference and Harley Wood Winter School

2009-07-08T15:27:00.002+10:00

My head is spinning for all the information that has been funnelled into it over the last few days - it is amazing the depth of knowledge that is being studied in Astronomy in Australia. Lots of radio and cosmology studies and searching for blackholes, AGN's and the beginning of time.

Not a lot of stellar stuff or planetary science - athough yesterday there were some talks on the Sun and helioseismology. I have taken more notes than fit into a shorthand size notebook and had to buy another one!

Mind you I am more than ever convinced that those of us who actually enjoy looking at the sky and actually observing as opposed to theorising are a minority!

But that could be sour grapes because I must confess to being totally out of my depth on some of the models etc being discussed.

Still the food is incredible! People have looked at my poster!

The Sunspots are Returning!

2009-07-08T13:34:00.003+10:00

A new group of sunspots have developed over the last few days, and while not dramatic by historic standards, the spots were the most significant in many months as they may mark the end of one of the longest sunspot droughts of modern times - at least since 1913.

Solar activity goes in a roughly 11-year cycle. Sunspots are the visible signs of that activity, and they are the sites from which massive solar storms lift off.

The past two years have marked the lowest low in the cycle since 1913, and there have been losts of theories abounding as to the possible explanation for the prolonged minimum.

The new set of spots, named 1024, is kicking up modest solar flares.

Sunspots are cool regions on the sun where magnetic energy builds up. They serve as a cap on material welling up from below.

Often, that material is released in spectacular light shows called solar flares and discharges of charged particles known as coronal mass ejections.

The ejections can travel as space storms to Earth within a day or so, and major storms can knock out satellites and trip power grids on the surface.

Prior to the low-activity period, astronomers had been predicting that the next peak in solar activity, expected in 2013, might be one of the most active in many decades.

Been slack lately

2009-05-27T08:25:00.003+10:00

Well, it is a while since I posted. Been really busy at work - Was observing on the 2.3M from May 4-11 and prior to that was receiving training on the new WiFeS instrument.

Had a look at C/2007 Q3 Siding Spring which is one of the two comets I found while working at Uppsala. Also took a cool pic of Comet Garrard with the

After my run finished I had a few nights doing support astronomer work for a lovely PhD student studying Tran Neptunian Objects and doing support for another group on the new instrument. So that was around 15 nights straight and the weather was good all that time - can you believe it! Since then I had one Saturday off which I slept most of and then have been organising the Open Day here as well working with the Protocol folks from ANU to organise the event for the Opening of Skymapper.

Today I have to finish off paperwork then head off to Canberra for the final day of a training course for Supervisors.

Then back to finishing off my data reduction of all the data I received, I have a Poster Paer to prepare and a real paper and get my Thesis back on track.

Western Sydney Astronomy Group Talk

2009-04-16T11:14:00.003+10:00

Last night I had a great time out at the Observatory at University of Western Sydney - after an amazing meal at the Indian restaurant at Kingswood (thanks guys!). The meeting was incredible fun and the people enthusiastic and keen - I really enjoyed myself and hopefully I did not bore anyone too much with my stories of the trials and tribulations of working at Siding Spring!

The Astroinformatics School I am also attending at Uni of Sydney is also great and I am learning heaps - but boy am I tired after the few nights of observing clouds from the AAT!

Keep our Skies dark!

2009-04-11T01:35:00.002+10:00

This year, the International Year of Astronomy (IYA) "Dark Skies Awareness" Global Cornerstone Project is endorsing Dark-Sky Week on a global level as the International Dark Skies Week (IDSW), as part of IYA's dark skies preservation efforts. The first night of IDSW will coincide with the Starlight Initiative's "World Night in Defense of Starlight."

National Dark-Sky Week (NDSW) is an event in the United States, usually occurring in April, during which people in the United States are encouraged to turn out their unnecessary outdoor lights in order to temporarily reduce light pollution. Light pollution is a hazy blanket of light in the atmosphere caused by improper lighting fixtures which direct light up into the sky instead of down toward the ground. Not only does light pollution waste energy, but it also creates great problems for stargazers. This “blanket of light” causes the beauty of the night sky to fade, and if the problem of light pollution is not addressed now, we are destined to lose the beauty of the cosmos that have been a part of human civilization since its beginning.

This would be a really cool project to carry on from Earth Hour - so why not consider it for wherever you are in the world. Go outside and check out the night sky and see what you can see!

This weeks column sent off today

2009-03-23T11:17:00.000+11:00

This week sees Jupiter looking very prominent in the morning skies about 6 hand spans above the Eastern horizon an hour before sun rise. Jupiter is the largest of the planets in our own Solar System. It has a mass of 1.90 * 10^27 kg, more than twice as massive as all the other planets combined and a radius 11 times that of the Earth at 71,492 km.

Observed by Galileo, in the 1600’s it still amazes first time backyard viewers and just like him they can see its four largest moons, Io, Ganymede, Callisto, and Europa. Nowadays we know that Jupiter has at least 63 moons.

As of Saturday, the International Space Station is the now the second brightest object in the night sky. Unfortunately unless you caught over the last few you have missed out for at least another week or so until it becomes visible to southern viewers again. It will now be brighter than Venus with only the moon being brighter. The astronauts of the STS-119 mission successfully deployed the solar array truss segment, known as Starboard 6. Weighing 14,000 kilograms and measuring 5 metres wide and13.8 metres long and filled the whole of the shuttle’s cargo bay. The ISS now has four solar panels on each end of its power truss. This gives a total surface area of all the arrays of approximately one acre. This is capable of generating 84 to 120 kilowatts of useable power.

Another interesting note about this shuttle mission is that there are two teachers aboard and although they won’t be teaching from space – they contributed to the deployment of the solar panels and in fact carried out two space walks as part of the mission. Another piece of trivia – a bat was seen clinging to Discovery during launch – trying to hitch a ride perhaps?

There has been a lot of coverage in the media lately about small asteroids – or pieces of rock passing relatively close to the earth. On March 2nd, 2009 DD45 a 35 metre rock passed about 72000 kms above the earth, then last week 2009 FH a 20 metre asteroid passed 80,000 kms away and on Friday 2009 DO1111 a much larger rock passed 1.2 times the distance from here to the moon away from us. None of these posed any threat to the Earth and with improved technology more and more will be found. The surveys are out there searching for asteroids which are a threat to Earth and the plan is map all asteroids greater than 100m in diameter.

Coming up in April is the IYA 2009 cornerstone Project, 100 hours of Astronomy. It should be the single largest event taking place this year world wide. The event will take place over four days and nights, from 2-5 April 2009 (local time). During this period, amateur astronomer will share the experience of observing the sky. Locally a number of National Parks are running Starry Starry Night events and in a number of towns folks will be doing sidewalk astronomy – where we take our telescopes out onto the streets and show off the sky. Check out www.astronomy2009.org.au for what is happening around the region.

Don’t forget Earth hour next Saturday March 28th from 8.30 to 9.30pm. Turn off your lights and do your bit for climate change and also see the difference that turning off lights has on the night skies. Remember light pollution is the singles greatest threat to optical astronomy in this country.

Welcome to another week of what’s happening in the world of Astronomy

2009-03-18T17:50:00.001+11:00

8.30 pm March 28th is Earth Hour this year. This is set aside as a time to turn off your lights for one hour to take part in a global event, which is aimed at drawing attention to the need to address the problem of climate change. But as an astronomer, there is another reason why this project is important. Light pollution is the number one threat to the work we do at Siding Spring and other optical observatories around the world.

Light pollution is the illumination of the night sky caused by artificial light sources on the ground (streetlights, billboards, etc.). Both the light and the loss of contrast make it difficult to find fainter stars and nebulae. The amount of outdoor lighting increases as a result of increasing population. As cities and suburban areas grow, the number of lights at night also increases. Lights, contrast, and glare all impact the number of stars that are visible in a given location. Only the brightest stars are visible when there is a lot of night time lighting.

This light is scattered in the atmosphere by particles and aerosols causing the air above urban areas to glow. The end result is that we are unable to see most of the 2500 stars that would normally be seen under dark skies. Astronomers at Siding Spring Observatory are affected in their research by sky glow as far away as Sydney and suburbs. Reducing sky glow, unlike other forms of pollution, actually saves us money and also helps reduce greenhouse gas emissions as well as ensures we can still can enjoy the night sky.

So, while the lights are out for that hour on March 28th and you have the BBQ fired up there is another IYA project you can have a go at!

You don’t need special equipment and you don’t even need to leave home. Between March 16 and March 28 you can participate in one of the IYA cornerstone projects called the Globe at Night. The project invites people to participate in the annual global sky observation known as GLOBE at Night. GLOBE at Night brings people outside to observe the constellation Orion from 16-28 March 2009. Participants simply choose a clear night on which stars are visible, count how many stars you can see in Orion – in particular in his belt and the sword (or for those of us who know it as the saucepan – in the base and the handle), record the time and place and weather conditions such as partly cloudy, clear etc and let me know your results. I am also putting together a kit for groups to use and send back to Siding Spring as a part of this project. If you would like to participate or request a copy just contact me on the details below.

Orion is almost overhead after sunset and then gradually moves towards the west during the night.

More asteroids to Buzz the Earth this week

2009-03-18T13:51:00.002+11:00

A newly-discovered asteroid designated 2009 FH will fly past Earth tonight only 80,000 km (0.00057 AU) away. It was discovered by the NASA's US based Near Earth Object Observation Program, known as Spaceguard. 80,000 km is a little more than twice the height of a geosynchronous communications satellite. Experienced amateur astronomers in North America should be able to photograph the 20-metre-wide space rock racing through the constellation Gemini after sunset tonight. For Southern Observers, it will be very low on the horizon and only visible for about an hour after sunset. It should be about as bright as a 14th magnitude star. You can get an ephemeris and updates at spaceweather.com.

Interestingly, this new object comes only two weeks after a larger (50 metre wide) asteroid 2009 DD45 was spotted passing the Earth at a similar distance on March 2nd. So it begs the question, why are we seeing so many asteroids lately?
On March 2nd, 2009 DD45 passed by only 72,000 km away. Measuring some tens of meters in diameter, 2009 DD45 and 2009 FH are approximately Tunguska-class objects, meaning they pose no global threat but could cause local damage if they actually hit Earth. In years past, asteroids of this size often passed unnoticed, but recent improvements in asteroid surveys have resulted in growing numbers of space rocks caught in the act of near-Earth flybys.

"This asteroid flyby will be a good viewing opportunity for both professional and amateur astronomers," said Don Yeomans from the Near-Earth Object Office at NASA's Jet Propulsion Laboratory in Pasadena, California. "The asteroid poses no risk of impact to Earth now or for the foreseeable future."

There will be another recently discovered rather larger piece of rock designated 2009 DO111 which will pass by around 1 and a quarter lunar distances away. This one which is between 70 and 170 meters in size was first spotted by the Steward Observatory at Kitt Peak USA. It won't be visible down under though.

Although it might seem there are a lot more asteroids than before, this isn't the case, the technology is just getting better at finding them.

2009-03-05T15:19:00.002+11:00

AStronomers using ESO's Very Large Telescope have been able to gain a valuable new insight regarding the atmosphere of the dwarf planet Pluto. They found unexpectedly large amounts of methane in the atmosphere, and also that the atmosphere is hotter than the surface by about 40 degrees, although it still only reaches a raher chilly minus 180 degrees Celsius. These properties of Pluto's atmosphere may be due to the presence of pure methane patches or of a methane-rich layer covering the dwarf planet's surface.

check ou the rest of the story at http://spacefellowship.com/News/?p=8341

so I wonder if any other dwarf palnets have an atmospere as well

That lump of rock better known as 2009DD45

2009-03-04T17:30:00.003+11:00

Well, I can't believe the reactions of the press here in Australia to coverage of the near earth asteroid discovered by my friend and colleague Rob McNaught last Friday morning - a small fast moving 19 magnitude blip on his regular survey images - the approx 100' in size piece of rock was still about 1.5 million kms away from us. As usual he took a number of follow up images as did others who constantly follow up discoveries listed on the MPC web page and it became clear that it would certainly come between the earth and the moon but at a relatively safe distance of around 65,000 kms up about twice the distance from the surface of the Earth to the geostationary satellites orbit ting above us.

Now it was predicted to make its closes approach on Tuesday morning at 12.45am AEDST and so was a good opportunity for amateurs to have a look from their backyards as it brightened by more than 5000 times between Friday and Tuesday - except that here is was too hard to do more than catch glimpses through clouds!

this weeks column for the local papers

2009-03-04T01:26:00.001+11:00

Autumn has arrived again, and the nights are getting longer. Anyone wandering out and about at night can take the opportunity to stare up at the Autumn skies and see the Milky Way, and the constellations of Carina, Puppis and Vela, blaze across our night sky. Orion the Hunter and his dog Canis Major are also magnificent. Nights are often cool now, so don't forget your warm jumper before doing any extended star watching.

Venus is still a spectacular crescent low in the western skies at sunset for the first week of the month – by the 13th you won’t be able to see it anymore of an evening.

Comet Lulin looks great in binoculars still even though it is fading.

Looking at the eastern horizon and if you can find the upside down question mark which is Leo and move your binoculars to the left you will find the comet. The circles show the field of view of 10x50 binoculars. Comet Lulin will pass the Beehive cluster of the 6th and 7th of March, then the waxing Moon will make the comet difficult to see.

Mercury , Mars and Jupiter are quite easy to find in the morning sky this month – you probably need to get up about 5,30am to see then well in the east but if you are up it is certainly worth the effort to go outside and see them.

On Friday evening, Rob McNaught working on the Near Earth Object Siding Spring survey found a small (less than 30mtres in diameter) surprise, which has been given the designation 2009 DD45. It was only a 19th-magnitude blip in images taken by Rob. At that time it was already within 1½ million miles of Earth and closing fast. Why am I mentioning this? Well, because this small asteroid will pass close to Earth tomorrow morning 00:44 AEDST. So how close will it get? It is calculated that it will be that it'll be 0.00047 of an astronomical unit from the centre of the earth or in more normal terms about 63,500 km up. This distance will put it well within the orbit of the Moon but at least twice as high as the altitude of most communications satellites!

This is no threat to the Earth but just interesting as it was discovered locally only a few days ago. Just for interest, this isn't the closest "near-miss" asteroidal fragment on record. That belongs to tiny 2004 FU162 which skirted just 5,500 kilometres from us on March 31, 2004.

where are the planets in the sky at present

2009-03-04T01:17:00.003+11:00

Sun:in Aquarius, 32.3 arcmin in diameter.
Moon:moving through Taurus, disc is 41% illuminated (waxing crescent), visible in the sky after sunset, 80 degrees from the Sun, 32.0 arcmin in diameter.
Mercury:in Capricornus, visible in the eastern sky before sunrise, appears close to Mars and Neptune, magnitude -0.2, 21 degrees from the Sun, 5.5 arcsec in diameter.
Venus:in Pisces, visible in the western sky after sunset, magnitude -4.6, 32 degrees from the Sun, 47.6 arcsec in diameter.
Mars:in Capricornus, visible in the eastern sky before sunrise, appears close to Mercury and Neptune, magnitude 1.0, 22 degrees from the Sun, 4.1 arcsec in diameter.
Jupiter:in Capricornus, visible in the eastern sky before sunrise, magnitude -2.0, 29 degrees from the Sun, 33.2 arcsec in diameter.
Saturn:in Leo, visible in the sky before sunrise and for most of the night, magnitude 0.6, 173 degrees from the Sun, 19.7 arcsec in diameter.
Uranus:in Aquarius, probably too close to the Sun to be seen, magnitude 5.9, 8 degrees from the Sun, 3.1 arcsec in diameter.
Neptune:in Capricornus, visible in the eastern sky before sunrise, appears close to Mercury and Mars, magnitude 8.0, 18 degrees from the Sun, 2.0 arcsec in diameter.

A New Fuzzy Visitor to our Skies.

2009-02-23T10:30:00.000+11:00

Discovered in July 2007, and known officially as C/2007 N3 (Comet Lulin) is an interesting visitor to our skies this month. It was discovered by a 19-year old university student in China on a photograph taken at Taiwan’s Lulin Observatory. It is easily visible in binoculars and certainly over the last few nights I have been able to see it the unaided eye. It is the only fuzzy object in the area. In a telescope, it looks a bit like a sword with a long dim tail and a smaller dim anti tail. In photographs it has a green tinge to it. In a pair of 10 x 50 binoculars it looks like a large fuzzy ball.

Comets are often referred to as "dirty snowballs." They are left over from the formation of stars and planets billions of years ago. They live in an area of space outside the orbit of Pluto called the Oort cloud. Usually made of chunks of frozen gases, ice and rocks and although some may be a few hundred kilometres across most are no more than a kilometre across. Every now and again one of these snowballs gets disturbed in its orbit and fall in towards the Sun.

As they get closer to the Sun, they start to heat up. The ice transforms directly from a solid to a gas and releases dust particles which were embedded inside the ice.

Sunlight and the stream of charged particles flowing from the sun – the solar wind – sweeps the evaporated material and dust back in a long tail. The comet's ingredients determine the types and number of tails.

Lulin’s closest approach to Earth, 0.41 astronomical units or 61 million kilometres (an astronomical unit is the distance from earth to the Sun- approximately 150 million kms) will occur on February 24th, when the comet should be at its peak brightness. At this time the comet will pass really close to Saturn in the sky. In fact, they will both be within the same binocular field of view field of view. Saturn is about 3 hand spans above the north-eastern horizon at around 10pm and nearly halfway between the bright stars Regulus and Spica. It looks distinctly yellow in colour and this should make it easier to spot.

This will be no replay of Comet McNaught from January 2007 but should still be bright enough that most of us can see it as a fuzzy ball in the sky and certainly worth the effort of having a look with binoculars if you do not have a telescope.

On the night of February 25th the comet goes through opposition, nearly 180° from the Sun in our sky. There is always the possibility of seeing some interesting effects with the tail and brightness when it goes through opposition.

After that Lulin moves away from both Earth and the Sun, so it will tend to fade quickly. The evening of February 27 will see it at about 6th magnitude within 1° of Regulus which is the brightest star in the constellation of Leo. Leo looks like an upside question mark to those of down under – rather than a roaring lion.

Unfortunately, if you miss it this time around, Comet Lulin won’t be returning again to the inner solar system for more than a thousand years.
Happy comet hunting!

Also, and a lot easier to see on February 28, you can see the crescent moon close to Venus, just a hand span above the western horizon half an hour after sunset. Venus looks great in binoculars at present. This is one of the last good opportunities for viewing this year in the evening.

Comet Lulin

2009-02-20T12:10:00.002+11:00

nice and easy to find after midnight in binoculars then naked eye - about 5.3-5.4 mags nothing else like it nearby. On the 24th it should be in teh same binoculaar field as saturn so that will make it a bit easier for those who haven't seen it yet - looks nice.

On a different note my column in namoi independent will also be in Coonabamble Times as well as Coonabarabran Times... so that should be fun!

Venus..

2009-02-16T12:06:00.001+11:00

the column submitted to Namoi Independent

Venus – the brightest of all the Planets.

As discussed last time, over the next few weeks we are going to consider the planets the Galileo could see and look at how we can find them in the sky.

Last week, we discussed Mercury, in its role of morning star. Don’t forget if you are out early next Monday (Feb 23) at around 6am before the sun comes up – you will be able to see Jupiter, Mercury and Mars very close to the crescent moon.

This month finds Venusin the constellation of Pisces and at its brightest. Even in small telescopes, Venus can be seen to dramatically increase in size and go from being a "half Moon" shape to a distinct crescent, however as Venus gets closer to the horizon it will be harder to see. Towards the end of the month Venus's crescent shape may be seen in powerful binoculars.

Venus, named after the goddess of love, is the brightest of all the "stars" in the sky. Even though it is always covered with thick cloud, so we can't see its surface, we know more about the surface of Venus than the surface of any other planet. More than 20 spacecraft have visited Venus which is more than have visited any other planet in the solar system.

Almost an identical twin to Earth in mass and size it is the hottest and flattest of all of the planets in the inner solar system. On Earth, we generally find that there are few clouds higher than 15 km above sea level and on average; only about 50% of the Earth’s surface is covered by cloud at any given time. On Venus, however, clouds cover 100% of the surface constantly. The clouds don’t start until about 50 km above the surface, and then extend for another 25 km. They are made up of droplets of sulphuric acid, which are about 50 times smaller than the thickness of a human hair. On Venus it takes 225 earth-days to make a complete orbit of the Sun and we don’t understand why, but the planet rotates in an opposite direction to all the other planets in the Solar System (except Uranus). A day on Venus lasts the equivalent of 243 Earth Days, hence on Venus a day is longer than a year.

Lightning also seems to be as common on Venus as it is on Earth with most of the lightning happens within the thick high cloud deck. The clouds on Venus though race around the planet nearly 60 times faster than the surface rotates and just like on Earth, the thunderstorms and lightning on Venus seem to happen mostly in the afternoon and at dusk.

On February 28, you will see the crescent moon close to Venus, which by that the end of the month is just a hand span above the western horizon half an hour after sunset.

If you have any questions about what you see in the sky or want more information on what is on in this International year of Astronomy, please feel free to contact me – Donna Burton, Australian National University, Siding Spring Observatory, Coonabarabran 2357, phone 6842 6255 or via email donna@mso.anu.edu.au. Remember – The Universe – it is Yours to Discover!

So much for the big sky principle

2009-02-13T14:20:00.004+11:00

Colliding satellites....

Here is a cool animation of the collision which I guess was inevitable when you consider how much is up there.

http://i39.tinypic.com/2vbk75z.gif

The collision which occurred on February 10th, approximately 800 km over northern Siberia, involved a US Iridium commercial satellite(Iridium 33) , which was launched in 1997, and a Russian satellite (Kosmos 2251) launched in 1993 and believed to be non functioning. Each satellite weighed well over 1,000 pounds. The ISS is safe at present from the approximately 500 pieces debris as it is in orbit only 350km above the Earht.

This is the fifth spacecraft/satellite collision to occur in space, but the other four were all fairly minor by comparison.

Planets - where are they tonight

2009-02-12T11:45:00.001+11:00

Sun:in Capricornus, 32.4 arcmin in diameter.
Moon:moving through Leo, disc is 93% illuminated (waning gibbous), visible in the sky before sunrise and for most of the night, 149 degrees from the Sun, 32.0 arcmin in diameter.
Mercury:in Sagittarius, visible in the eastern sky before sunrise, magnitude 0.1, 26 degrees from the Sun, 7.1 arcsec in diameter.
Venus:in Pisces, visible in the western sky after sunset, magnitude -4.6, 43 degrees from the Sun, 35.0 arcsec in diameter.
Mars:in Capricornus, visible in the eastern sky before sunrise, appears close to Jupiter, magnitude 1.1, 17 degrees from the Sun, 4.0 arcsec in diameter.
Jupiter:in Capricornus, visible in the eastern sky before sunrise, appears close to Mars, magnitude -2.0, 14 degrees from the Sun, 32.5 arcsec in diameter.
Saturn:in Leo, visible in the sky before sunrise and for most of the night, magnitude 0.6, 152 degrees from the Sun, 19.5 arcsec in diameter.
Uranus:in Aquarius, visible in the western sky after sunset, magnitude 5.9, 27 degrees from the Sun, 3.1 arcsec in diameter.
Neptune:in Capricornus, near conjunction, magnitude 8.0, 0 degrees from the Sun, 2.0 arcsec in diameter.

What is happening in the skies this February?

2009-02-09T13:52:00.000+11:00

Being able to find the planets can prove difficult when you are first starting out and are unfamiliar with the sky. However, the Moon is very obvious, and so can be used as a guide to locate the planets. As the moon transitions from full to new moon over approximately 14.5 days it is said to be waning and as it progresses from new moon to full then it is waxing. The whole cycle takes approximately 29 days.

On the evening of February 11, the waning Moon will be three finger widths away from the planet Saturn. Saturn has a distinctly yellow colour making it easy to spot – it rises before 10pm and at midnight is between 3 and 4 hand spans from the eastern horizon at midnight. Then on the morning of February 23 the thin crescent moon will be very close to Jupiter, Mercury and Mars.

Let us look at Mercury, one of the planets that you can see this month and over the next few of weeks we will discuss each of the planets that are easily visible in small telescopes as they were to Galileo.

Mercury is nice and easy to see in the morning skies this month. It is the planet closest to the Sun, a very small planet, only slightly larger than our Moon, with its "day" being nearly as long as its "year" of 88 earth days.

Because of its proximity to the Sun it has always been hard to see. It can only be seen for less than two hours before sunrise, or less than two hours after sunset. For this reason ancient astronomers believed that Mercury was actually two distinct planets. Mercury was the name they gave to planet seen in the early evenings, while Apollo was the name given to it when seen in the early morning. The Romans called this planet after Mercury, the wing-footed messenger of the gods, because it moved so fast through the sky.

The planet Mercury is literally a ball bearing of iron, with a thin layer of surface rock. About 80% of the diameter of the whole planet is taken up by its core of metallic iron. A strange fact that no one completely understands is that Mercury appears to be linked to the Earth. Every time Mercury reaches its closest distance to us, which occurs every 117 days, it always shows the same face to us.

February is the also best time to view Mercury in the mornings this year. On the 15th, it is two hand spans above the eastern horizon an hour before sunrise, with Mars and Jupiter just above the horizon below it. By the 28th, it will be just under two hand spans above the eastern horizon, and hour before sunrise. Mercury is accompanied by Mars and Jupiter for most of the month, but within this general planetary association Mercury has several interesting encounters. On February 23, the crescent Moon will be quite close to Mercury, with Jupiter and Mars close by. On February 25, Jupiter and Mercury are less than a finger width apart, with Mars below making a nice compact cluster.

Remember – The Universe – it is Yours to Discover!

Smallest Known Exoplanet may be even closer to Earth Size

2009-01-22T14:54:00.004+11:00

In 2007, David Bennett of the University of Notre Dame led an international team of astronomers made a discovery of an exoplanet they believed to be about 4 times the mass of the earth orbiting a brown dwarf star some 3000 light years from Earth. The team made the discovery gravitational microlensing. This method relies on analysing the way the host star bends light coming from another, more distant star. The presence of a planet can further distort the light. Many scientists believe that microlensing as a exoplanet detection method is coming into its own.

Performing such observations is notoriously difficult, but was made possible in this instance thanks to the sensitivity of the Microlensing Observations in Astrophysics (MOA) II telescope in New Zealand.

It was then independently confirmed by observations at the Very Large Telescope (VLT) in Chile.

The planet, which has the somewhat cumbersome name of MOA-2007-BLG-192Lb, is around 3000 light years from Earth. It is made mostly of rock and ice and orbits its star at about the same distance that Venus orbits the Sun, however, it is most likely much colder than Pluto due to the fact the host star appeared to be a brown dwarf.

Now they believe the planet may be even smaller than first thought - and its host star may be a red dwarf (not related to the TV series!) instead which means it is more heavier than a brown dwarf and makes the planet to be around 1.4 times the mass of the earth. Still the planet is likely to be frozen and unable to host life as we know it anyway. The teams hope to gather more data during April this year on a VLT run so let us see what they come up with next.....

Partial Eclipse Australia Day

2009-01-19T09:15:00.000+11:00

Throughout history, solar eclipses have been documented through stories, mythology and astrology. As far back as 2800 BCE the ancient Chinese observed a rhythm in the occurrence of solar eclipses, although in their mythology a dragon devoured the sun.

Chinese astrologers wrote of an eclipse occurring more than 4000 years ago. This eclipse, historians and astronomers believe, occurred on October 22, 2134 BCE. According to legend, two astrologers at the time, Hsi and Ho, were executed because they failed to predict this eclipse.
Many ancient civilizations believed the occurrence of an eclipse was a demon eating the sun. They thought that the best way to get rid of the “demon” that was consuming their sun was to unite and make as much noise as possible to scare it away. At the first sight of an eclipse, everyone would immediately gather to bang drums and shout or scream as loudly as possible. The ancient Greeks believed that an eclipse was a sign of angry gods, therefore it was thought of as a bad omen.
Solar eclipses have even altered the course of human history. In 585 BCE the Lydians and Medes were engaged in battle in what is present-day Turkey. The Greek historian Herodotus recorded that at the height of a particularly fierce battle, darkness fell upon the land. Apparently the two armies waged a war close to the path of a solar eclipse. The armies took this as a sign and stopped fighting instantly, making peace with each other.
These days, we know what causes eclipses to occur.
An eclipse of the Sun can only happen at New Moon when the Moon passes between Earth and Sun. If the Moon's shadow happens to fall upon Earth's surface at that time, we see some portion of the Sun's disk covered or 'eclipsed' by the Moon. Since New Moon occurs every 29 1/2 days, you might think that we should have a solar eclipse about once a month. Unfortunately, this doesn't happen because the Moon's orbit around Earth is tilted 5 degrees to Earth's orbit around the Sun. As a result, the Moon's shadow usually misses Earth as it passes above or below our planet at New Moon. At least twice a year, the geometry lines up just right so that some part of the Moon's shadow falls on Earth's surface and an eclipse of the Sun is seen from that region.
The Moon's shadow actually has two parts: the first is called the Penumbra and it is the Moon's faint outer shadow and the second is the Umbra which is the Moon's dark inner shadow. It is when the Moon's penumbral shadow strikes Earth; we see a partial eclipse of the Sun from that region. This is what will happen on January 26th. Partial eclipses are very dangerous to look at because the un-eclipsed part of the Sun is still very bright, so it is important to do so safely.
Viewing Solar eclipses require that you take some precautions prior to observing the eclipse. This is because the sun’s photosphere emits intense infrared and ultraviolet (UV) radiation. Just as UV radiation causes sunburn to skin, it can also damage the retinas in the eyes at a much faster rate. The human eye can suffer permanent damage if it is exposed to direct sunlight for a few seconds.
The safest way is to project the image of the Sun onto a suitable screen. Alternatively a suitable, specially designed, solar filter may be placed in front of the telescope.
It is NOT safe to use a filter at the eyepiece as the focussed heat from the Sun could shatter it. If unsure of safe methods consult your local astronomical society about suitable ways of observing solar events.
Another safe way to view an eclipse is to make a pinhole camera. Make a hole or a number of holes in a piece of card, and project the image to another card. You will see small images on which the eclipse will be clearly visible. You can adjust the distance the two bits of card are apart to increase the size of the image.

Don’t forget the Starry, Starry Night event in Warrumbungle National Park on the evening of the 24th and there will be behind the scenes walking tours 11am each morning of the long weekend. See www.astronomy2009.org.au and click on the calendar for more information on what is on!

Starry Starry Night - Coonabarabran

2009-01-08T09:09:00.000+11:00

The International Year of Astronomy 2009 (IYA2009) has been launched by the International Astronomical Union (IAU) and the United Nations Educational, Scientific and Cultural Organization (UNESCO) under the theme, "The Universe, yours to discover.”
400 years Galileo became the first astronomer to study the moon and planets using a telescope. Albeit, a very primitive one by today’s standards, it was still an incredible step forward for the science. The largest telescope here at Siding Spring has a 3.9m or 154 inch mirror. Galileo was the first person to observe the four large moons of Jupiter and notice that they went round the planet. He was the first man to see sunspots and the phases of Venus. All these observations led him to conclude that planets went round the sun.
Galileo constructed not one but two hundred telescopes and donated them to various educational institutes for astronomical observations. He wrote his book in Italian so that his countrymen would understand him. Thursday 8th January, is the anniversary of his death in 1642.
Throughout Australia and the world stargazers have started off an extensive round of events to celebrate the International Year of Astronomy. Over 135 nations are collaborating to bring the universe closer to Earth. Events and activities will take place over the coming 365 days and beyond in a spectacle of cosmic proportions.

While the official IYA2009 opening ceremony will take place in Paris on January 15-16, 2009, locally Starry, Starry Night events are being held at National Parks throughout the State to mark the commencement of the International Year of Astronomy.

Warrumbungle National Park, in conjunction with Siding Spring Observatory, has worked to put these nights together locally over the past year. Now, they are going to be held in National Parks right across the state. They are extremely popular and give people an opportunity to look at the stars in dark conditions. Experienced astronomy guides and local indigenous people are there to tell the stories of the wonders of the night sky. Local astronomers bring along telescopes and show the visitors interesting objects such as whatever planets may be visible, the craters of the moon and all sorts of interesting objects. Orion, better known down under as the Saucepan is a wonderful source of interesting objects to look at with the Great Orion Nebula, a massive star forming area making a lovely image through the eyepieces of the telescopes available. The telescopes we use are much bigger than Galileo’s and folks can hope to see some amazing objects. It is a great opportunity to ask questions and seek advice on telescopes and viewing the night sky.

These events are a great part of the International Year of astronomy as they really fir the theme of “The Universe – Yours to Discover”.

Me and my big mouth

2009-01-05T16:44:00.002+11:00

Well, I have gone and done it now - have agreed to write up a column for a paper in a nearby town every week to promote IYA2009. Now I have to decide what I want to write about. Obviously the first week is easy - I will write about IYA in general terms and what is happening out this way in more detail. I need ideas - but I am sure I can come up with something.

Meteor ShowerSunday Morning

2009-01-02T20:17:00.005+11:00

The Quadrantid (pronounced KWA-dran-tid) meteors provides one of the most intense annual meteor displays (particualrly if you live in the Northern Hemisphere), with a brief, sharp maximum lasting but a few hours.

The shower was discovered by Adolphe Quetelet of Brussels Observatory in the 1830's, and shortly afterward it was noted by several other astronomers in both Europe and America.

The meteors are named after the obsolete constellation Quadrans Muralis the Mural or Wall Quadrant (an astronomical instrument), depicted in some 19th-century star atlases roughly midway between the end of the handle of the Big Dipper and the quadrilateral of stars marking the head of the constellation Draco. (The International Astronomical Union phased out Quadrans Muralis in 1922.)

Hard to say but pretty good if you can see them. I was out on New Years Eve/morning ie at midnight - on the catwalk and you could see quite a few meteors to just North of East in the sky. They may have been sporadics but some were quadrantids.

Although the Quadrantids are a major shower, they are seldom observed. One reason is weather. The shower peaks in early January when northern winter is in full swing. Storms and cold tend to keep observers inside. Last year, NASA scientists went to extremes to gain a good view; they flew an airplane above the clouds and over the Arctic Circle where they saw many Quadrantids.

The shower doesn't last long, a few hours at most. Even dedicated meteor watchers are likely to miss such a sharp peak. In his classic book Meteor Astronomy, Prof. A.C.B. Lovell lamented that "useful counts of the Quadrantid rate were made in [only] 24 Januaries out of a possible 68 between 1860 and 1927. ... The maximum rate appears to have occurred in 1932 (80 per hour) although the results are influenced by unfavorable weather."

The source of the Quadrantid meteor shower was unknown until Dec. 2003 when Peter Jenniskens of the NASA Ames Research Center found evidence that Quadrantid meteoroids come from 2003 EH1, an "asteroid" that is probably a piece of a comet that broke apart some 500 years ago. Earth intersects the orbit of 2003 EH1 at a perpendicular angle, which means we quickly move through any debris. That's why the shower is so brief.

But don't despair - for those of us down under it may be possible to spot some long-pathed meteors around the peak of the shower on the 4th.

Something to look forward to:

The shower best suited for viewing in the Southern Hemisphere is the Eta Carinids which is active from 14th to 27th. The meteors are typically faint, with hourly rates of only 2 or 3 at the shower’s peak around the 21st. The shower is centred near the faint star Eta Carina, which is one of the most massive stars in our Galaxy and found near the Southern Cross. This central point is high in the south from midnight to dawn which is the best time for meteor observing.

check out spaceweather.com for more info and charts

January Night Skies

2009-01-02T02:41:00.002+11:00

Following closely on the biggest and brightest full moon of 2008 in December only a couple of weeks ago we have the biggest and brightest full moon of 2009, which occurs in January. On January 11, the moon reaches full and also on this date the moon is also at perigee and 222,138 miles from Earth. This bright, close full moon is the third brightest of the 25 year period from 1993 to 2017. Someone called me yesterday and wanted to know all about it and was it the biggest it would be in 1000 years. The rising full moon is always spectacular but it can be hard to tell the difference with your naked eye - best way of noticing is to take photos of the full moon each month and see for yourself over a year. This month it will be 357500 km from us and when it is at apogee (furtherest point) for example the full moon in July it will be 406232 km away.

Another bit of interest is that the earth will be its closest to the Sun at 2am Eastern Summer time - on January 4 when it will be a mere 147 million kilometres away. This is called perihelion and occurs every year in January. 6 months later the Sun is at Aphelion which will occur on July 4 2009 and will be furtherest away at arounf 152 million kilometres.

The first few weeks of the year will also be the best time in 2009 to see three bright planets at once after sunset. Mercury, Jupiter, and Venus are all in the southwest after sunset. On January 1, Jupiter and Mercury are about 2 degrees apart and Venus floats 29 degrees above. Jupiter is a bit brighter than Mercury but they are quite low and you need a clear western horizon. But Jupiter and Mercury will disappear quite quickly over the first few days of the month. So Venus will be left to reign supreme in the evening sky.

If you get up early enough later in the month you will be able to see Mercury, Mars and Saturn.

There is an a partial eclipse eclipse of the Sun during the month. Only a very small amount of the Sun’s disc will going to be covered by the Moon. This will happen on the evening of Australia Day, the 26th of January, Monday, the 26th of January.

From the eastern states, especially from Sydney, there will only be a small fraction of the Sun covered by the Moon. That will happen just before sunset, so you will only be able to see the eclipse for a short period before sunset. It will be better as we go further west across the country, and 34%, or just over one-third of the Sun’s width will be covered by the Moon as seen from Perth.

Please remember that it is dangerous to look directly at the Sun. You need to have appropriate equipment to be able to look at an eclipse of the Sun. The safest way to do so is, if you have access to a small telescope or a pair of binoculars, is to project an image of the Sun and look at the projected image on a piece of card.

If you do not have a telescope or a pair of binoculars, make a pinhole camera. Make a hole or a number of holes in a piece of card, and project the image to another card. You will see small images on which the eclipse will be clearly visible.

So what else can we see - other than having to stay up late because it is summer - it is quite pleasant viewing- last night at midnight I was outside and the Milky Way was so bright that you could easily see where you were going.

Anyway dominating the northern sky is the familiar constellation of Orion, often called the saucepan.

There is star on the lower right of the constellation which is a reddish star–one of the few stars in the sky that you can actually tell its colour. It is called Betelgeuse and is a giant star, hundreds of times greater in diameter than our own Sun.

The name Betelgeuse comes from Arabic, and it means ‘the armpit of the giant’. So, even though it sounds like a very exotic name, in fact it means something very mundane. It describes the location of the star in an old-fashioned constellation drawing, for the constellation of Orion. Of course it is all upside down to us as most constellations were named centuries ago in the northern Hemisphere.

Another Night Observing

2009-01-02T02:27:00.003+11:00

Well teh weather has been a bit weird today - lots of high clouds during the day and then it seemed to clear a little early in the night so were lots of holes but has been very bad seeing and clouds coming and going - though have some good data in the gaps - looks like we are at the southern edge of the big system and I hope we stay there - if I get tonight all okay that is 5 good nights out of 10 - lost 4 to weather and one to telescope issues. 3 nights left to go.

Was interested that no one claimed the star on the Harbour Bridge last night was for IYA2009. The Australian website has really been updated finally! (Okay so just teh front page anyway - still the same everywhere else!) So here is hoping there are going to besome great events! Maybe one of us could find another comet like C/2006 P1 McNaught.....

I have to sort out some issue with this reduction software - observing is fun but trying to reduce the data on the fly is fraught with perils no one ever thought to mention.

My 12.5" dob mirror really needs a new coat of aluminium - wonder if I can't get it in with the 2.3m in March.

Happy New Year

2008-12-31T21:46:00.002+11:00

Only a couple of hours and it will be 2009 - a great year for astronomy with it being the international Year of Astronomy - we have heaps of great things planned here for Coonabarabran- the Astronomy Capital of Australia!

Currently my New Year looks great! I am observing on the 2.3M ANU telescope here at Siding Spring and collecting heaps of data - I have a 13 night run lost 5 nights so far to weather and telescope issues but now am getting loads of good data - I am doing a couple of things - looking at a list of unresolved variables from Hipparchus catalogue mainly K and G types to find target stars for follow up Doppler imaging - have so far found a number of double stars as well a few possible candidates. Out of it I am now looking to see if the echelle instrument on the 2.3M can be used to do actual doppler imaging so I have a star I found on my August run, one of the other guys stars and a well known magnetically active star which I am observing most nights to see if I can get sufficient data to prove my conceptual idea. Though achieving more time on the 2.3M may be difficult when the new WifEs instrument comes on later this year!

Still I should have enough data for my Master's thesis which I need to write this year and hopefully more than one paper.

So plan is for hopefully good weather for the rest of the run and then the hard work begins - I am doing rough reductions as I go but there is a lot to do and follow up and all the calculations to look forward to

Anyway - back to work - more images to look at - looking forward to visiting my colleagues over at the AAT catwalk to see if we can see the fireworks down town!

Water, water everywhere .... in a galaxy far, far away

2008-12-22T18:12:00.002+11:00

It appears that scientists have detected water in a galaxy 11.5 billion light-years from Earth.(definitely a long, long way away!)

Evidence has come in the form of emissions from water masers around a quasar at the centre of the distant galaxy. Detection at such a large distance was made possible by a closer, intervening galaxy which acted as a gravitational lens. This is commonly called "gravitational lensing" and acts almost like a magnifying glass in a very simplistic manner.

We were only able to discover this distant water with the help of the gravitational lens,' said Violette Impellizzeri, an astronomer with the Max-Planck Institute for Radioastronomy (MPIfR) in Bonn, Germany. 'This cosmic telescope reduced the amount of time needed to detect the water by a factor of about 1,000,' she added. The astronomers first detected the water signal with the Effelsberg telescope. They then turned to the VLA's sharper imaging capability to confirm that it was indeed coming from the distant galaxy. The gravitational lens produces not one, but four images of MG J0414+0534 as seen from Earth. Using the VLA, the scientists found the specific frequency attributable to the water masers in the two brightest of the four lensed images. The other two lensed images, they said, are too faint for detecting the water signal. The radio frequency emitted by the water molecules was Doppler shifted by the expansion of the Universe from 22.2 GHz to 6.1 GHz."

See the full story at: http://www.nrao.edu/pr/2008/farwater/

So why does it matter - So often when we think or talk about life as it may exist outside of our planet and solar system we always seem run into the problem of defining the term life. Because of our limited understanding, we search for pockets of water, which ought to at least provide a certain frame of reference close to our own in which we could find something that resembles life as we know it.

But are we overlooking life that we just don't understand and haven't the means to detect yet.

Finding water at these distances isn't so much the search for alternate worlds to habitate when we lose our Earth, it is much more a search for life similar to ours. But perhaps, I wonder, we are missing a whole range of other life in the universe due to our lack of capacity to imagine other types of life.

Biggest Brightest Full Moon of the Year

2008-12-10T14:19:00.002+11:00

The full Moon on Friday will be the biggest and brightest full Moon of the year.

It's no illusion. Some full Moons are genuinely larger than others and this Friday's is a whopper. Why? The Moon's orbit is an ellipse with one side 50,000 km closer to Earth than the other. In the language of astronomy, the two extremes are called "apogee" (far away) and "perigee" (nearby). On Dec. 12th, the Moon becomes full a scant 4 hours after reaching perigee, making it 14% bigger and 30% brighter than lesser full Moons we've seen earlier in 2008.

A perigee Moon brings with it extra-high "perigean tides," but this is nothing to worry about, according to NOAA. In most places, lunar gravity at perigee pulls tide waters only a few centimeters (an inch or so) higher than usual. Local geography can amplify the effect to about 15 centimeters (six inches)--not exactly a great flood.

Okay, the Moon is 14% bigger, but can you actually tell the difference? It's tricky. There are no rulers floating in the sky to measure lunar diameters. Hanging high overhead with no reference points to provide a sense of scale, one full Moon looks much like any other.

The best time to look is when the Moon is near the horizon. That is when illusion mixes with reality to produce a truly stunning view. For reasons not fully understood by astronomers or psychologists, low-hanging Moons look unnaturally large when they beam through trees, buildings and other foreground objects. On Friday, why not let the "Moon illusion" amplify a full Moon that's extra-big to begin with? The swollen orb rising in the east at sunset may seem so nearby, you can almost reach out and touch it.

The Moon is 384,400 km away (on average). At that distance, the smallest things Hubble can distinguish are about 60 metres wide.

From NASA Space News

PAN STARRS - largest digital cameras ever built to search for Near Earth Objects

2008-11-26T14:47:00.001+11:00

"The world's largest digital camera is to be used to keep an eye out for asteroids heading towards Earth. The Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) has been built by researchers at MIT's Lincoln Lab. At its heart is a 1.4 billion pixel (or 1400 megapixel) camera that will scan the night sky looking for rogue near-Earth objects from atop Mount Haleakala in Maui Island, Hawaii. The system an orthogonal transfer CCD to remove atmospheric blur from images."

Pan-STARRS is an innovative design for a wide-field imaging facility being developed at the University of Hawaii's Institute for Astronomy.

By combining relatively small mirrors with very large digital cameras we will be able to develop and deploy an economical observing system that will be able to observe the entire available sky several times each month.

The immediate goal of Pan-STARRS is to discover and characterize Earth-approaching objects, both asteroids & comets, that might pose a danger to our planet.

The huge volume of images produced by this system will provide valuable data for many other kinds of scientific programs.

The four PanSTARRS cameras will each be the largest digital cameras ever built. Each camera will have about 1.4 billion pixels spread over an area about 40 centimeters square. For comparison, a typical domestic digital camera contains about 5 million pixels on a chip a few millimeters across.

December 1st - smiley face in the night sky

2008-11-25T11:31:00.003+11:00

If you go out in the sunset tonight..... you will be in for a big sup rise... a smiley face looking down at you from the western horizon - on December 1st that is...

There will be a crescent moon and Jupiter and Venus will very close together in the evening sky. Great opportunity for photographs against interesting foregrounds.

The story starts now and ends with the best sky show of the year--a spectacular three-way conjunction of Venus, Jupiter and the crescent Moon.

It begins tonight with a sunset stroll.

At the end of the day, when the horizon is turning red and the zenith is cobalt-blue, step outside and look southwest. You'll see Venus and Jupiter beaming side-by-side through the twilight. Glittering Venus is absolutely brilliant and Jupiter is nearly as bright as Venus.

Go out and check each night and see how much closer they are.

On Nov 30, a slender 10% crescent Moon leaps up from the horizon to join the show. The delicate crescent hovering just below Venus-Jupiter will have cameras clicking around the world. But the first is the best show of all...

The now-15% crescent Moon moves in closer to form a triangle with Venus and Jupiter. The three brightest objects in the night sky will be gathered so tightly together, you can hide them all behind your thumb held out at arm's length.

The celestial triangle will be visible from all parts of the world, even from light-polluted cities. People in Sydney adn Brisbane will see it just as clearly as those of us in the bush. Only cloudy weather can spoil the show.

Although you can see the triangle with naked eyes--indeed, you can't miss it—a small telescope will make the evening even more enjoyable. In one quick triangular sweep, you can see the moons and cloud-belts and Galilean moons of Jupiter, the gibbous phase of Venus (69% full), and craters and mountains on the Moon. It's a Grand Tour you won't soon forget.

First lady Comet Hunter - Caroline Herschel

2008-11-19T08:50:00.001+11:00

Caroline Herschel is often overshadowed in history by her famous brother William Herschel but she is an incredible lady in her own right and in fact was the first professional lady astronomer and comet discover! Someone to see an example of what can be achieved. An inspiration!

here is her story in brief.

Caroline Herschel was born in 1750 in Hanover, Germany, the eighth of ten children. After contracting a virulent strain of smallpox as a child, unfortunately she was disfigured and was seen as having few prospects for marriage. Her family's limited means restricted her prospects for higher education or advancement. At the age of 22, Caroline went to live with her brother William, who had moved to England to teach music. At first, she was essentially a housekeeper. But her brother taught her mathematics and she learned to help him make larger and larger telescopes. She slowly gained expertise and self-confidence as a technician and telescope maker.

After William discovered Uranus, King George III paid him a salary of 200 pounds a year as well as paying Caroline 50 pounds a year to be her brother’s assistant. So Caroline became the world's first female professional astronomer.

While William set about measuring double stars, Caroline began sweeping the skies with a small refractor telescope, searching for faint deep sky objects not catalogued by Messier. Her first discovery was the open cluster, now called NGC 2360, made on February 26, 1783. This was the first of 14 deep sky objects that she discovered.

Her deep-sky discoveries inspired William. He gave up his double star observations and began to map the heavens once he understood the riches to be discovered there. His diligence led to the mapping of hundreds of additional deep sky objects, which led to the New General Catalog (NGC) used by astronomers to this day.

Caroline helped her brother with his catalog and continued to observe. In her free time, she swept the sky with her four-inch refractor and discovered eight comets between 1786 in 1797. Comet seeking was her favourite activity, and her discoveries cemented her reputation as a first-class astronomer.

After William died in 1822, when Caroline was 75, she returned to Hanover to complete William’s catalogue of deep sky objects. She lived until she was 97 years old, clear-minded and active until the end. She received honours from the Royal Astronomical Society, the Royal Irish Academy, and was awarded the gold medal for science by the King of Prussia.

From her epitaph: "The gaze of her who has passed to glory was, while below, turned to the starry Heaven: her comet discoveries, and her share in the undying work of her Brother, William Herschel, shall tell of this to all time."

planets in the sky tonight

2008-11-05T21:15:00.000+11:00

Moon: moving through Capricornus, disc is 42% illuminated (waxing crescent), visible in the sky after sunset, 81 degrees from the Sun, 29.9 arcmin in diameter.
Mercury: in Virgo, visible in the eastern sky before sunrise, magnitude -0.8, 12 degrees from the Sun, 5.2 arcsec in diameter.
Venus: in Ophiuchus, visible in the western sky after sunset, magnitude -4.3, 37 degrees from the Sun, 14.4 arcsec in diameter.
Mars: in Libra, probably too close to the Sun to be seen, magnitude 1.4, 8 degrees from the Sun, 3.7 arcsec in diameter.
Jupiter: in Sagittarius, visible in the sky after sunset, magnitude -2.1, 64 degrees from the Sun, 35.8 arcsec in diameter.
Saturn: in Leo, visible in the sky before sunrise, magnitude 1.0, 54 degrees from the Sun, 16.7 arcsec in diameter.
Uranus: in Aquarius, visible in the sky after sunset, magnitude 5.8, 125 degrees from the Sun, 3.4 arcsec in diameter.
Neptune: in Capricornus, visible in the sky after sunset, magnitude 7.9, 98 degrees from the Sun, 2.1 arcsec in diameter.

Discover Magazine has an article on the search for new earth like planets

2008-10-12T15:33:00.002+11:00

http://discovermagazine.com/2008/nov/10-how-long-until-we-find-a-second-earth

Discover Magazine is running a story detailing the search for planets like Earth orbiting other stars. While we've been able to locate a few "super earths" so far, none of them really compare in size or the potential for habitability with our own world.

Fortunately, advances in data analysis and new space-based telescopes such as Kepler, the hopefully one day to be launched James Webb Space Telescope, as well as the already launched and in orbit CoRoT have some astronomers predicting we'll find such an exoplanet by 2010, and a habitable one by 2012. Earth-based telescopes are also in the hunt, though the article notes, "even if a habitable Earth-like world is found first from the ground, it will most likely take a space observatory to search for the chemical signals that tell us what we really want to know: Is anything living out there? If the planet is one that can be observed
transiting, it just might be possible to provide a hint of an answer in the next few years."

Small Asteroid Predicted to Cause Brilliant Fireball over Northern Sudan (2008 TC3)

2008-10-07T17:47:00.003+11:00

From Nasa/JPL

http://neo.jpl.nasa.gov/news/news159.html

A very small, few-meter sized asteroid, designated 2008 TC3, was found Monday morning by the Catalina Sky Survey, (the Siding Spring Survey is the Southern partner in this endeavour) from their observatory near Tucson Arizona. Preliminary orbital computations by the Minor Planet Center suggested an atmospheric entry of this object within a day of discovery. This object, with the survey-assigned designation 8TA9D69, was discovered by the University of Arizona Mt. Lemmon survey and will almost certainly, tonight, become the first impacting bolide discovered before entry into the Earth’s atmosphere.

JPL confirmed that an atmospheric impact will very likely occur during early morning twilight over northern Sudan, north-eastern Africa, at 2:46 UT Tuesday morning which is 13:46 local time here in NSW Autralia. The fireball, which could be brilliant, will travel west to east (from azimuth = 281 degrees) at a relative atmospheric impact velocity of 12.8 km/s and arrive at a very low angle (19 degrees) to the local horizon. It is very unlikely that any sizable fragments will survive passage through the Earth's atmosphere.

Based on 26 optical observations from 2008/10/06.278 to 2008/10/06, the probability of impact is between 99.8% and 100%; in practice the impact can be considered sure and is for tonight. The effect of this atmospheric impact will be the release, in either a single shot or maybe a sequence of explosions, of about 1 kiloton of energy. This means that the damage on the ground is expected to be zero. The location of these explosions is not easy to predict due to the atmospheric braking effects. The only concern is that they might be interpreted as something else, that is man-made explosions. Thus in this case, the earlier the public worldwide is aware that this is a natural phenomenon, which involves no risk, the better.

Just to allay the fears of anyone who might panic: A few dozen meteoroids between 1 and 10 meters diameter are confirmed to enter Earth's atmosphere annually, with the actual number being perhaps an order of magnitude greater. What makes this interesting is that this is the first time such an event has been predicted ahead of time and it reflects the increasing capability of the Spaceguard Survey.

See you can all sleep tight at night knowing the team on the NEO survey both here at SSO and up there in the North are on the job!

Spaceweather.com has only an hour ago reported that the 3 metre diameter asteroid 2008TC3 hit the earth’s atmosphere over the Sudan. Impact speed was calculated to be about 12 km per second which is fairly slow.

WOW - Gemini has taken a picture of a planet!

2008-09-16T11:34:00.004+10:00

Well - that's the way the press reads and it sure looks good.

http://www.gemini.edu/node/11126

It seems that Gemini North telescope has taken the first photo of an exoplanet. the planet whih cis 8 times the mass of Jupiter orbits a star about 500 light years away from earth with the delightful designation of 1RSX J160929.1-210524. This planet would appear to lie about 330 times the distance of the earth from the sun (AU) away from its star. For comparison - Neptune only lies 30 AU from our Sun. THis star is slightly smaller and cooler than our Sun.

This really challenges a lot of thinking about exoplanets as it is in orbit much farther out than previoously considered. There are theories around about free roaming planets out there. It will take at least another 2 years to confirm that the Sun and star are gravitationally bound.

Well - we are mostly all here still!

2008-09-11T14:37:00.002+10:00

Scientists have hailed a successful switch-on for an enormous experiment which will recreate the conditions a few moments after the Big Bang.

They have now fired two beams of particles called protons around the 27km-long tunnel which houses the Large Hadron Collider (LHC).

The first - clockwise - beam completed its first circuit of the underground tunnel at just before 0930 BST. The second - anti-clockwise - beam successfully circled the ring after 1400 BST.

So far, all the beams have been stopped, or "dumped", after just a few circuits.

On Thursday, engineers hoped to inject clockwise and anti-clockwise protons again, but this time they plan to "close the orbit", letting the beams run continuously for a few seconds each.
It appears that low-energy collisions could happen in the next few days. This will allow engineers to calibrate instruments, but will not produce data of scientific interest.

"There it is," project leader Lyn Evans said when the beam completed its lap. There were cheers in the control room when engineers heard of the successful test.

The Edinburgh scientist who gave his name to the Higgs Boson particle said it was "pretty likely" it would be found by the Big Bang experiment.

Professor Peter Higgs, 79, expressed confidence he would be proved right, 44 years after he proposed his theory.

Scientists hope the Large Hadron Collider operated by Cern will uncover the sought after particle, which is sometimes called the God Particle.

It is a theoretical explanation for the origin of mass in the Universe

It is also thought without the particle there would be no gravity.

But the particle - nicknamed the God Particle because it is thought to be so fundamental to the evolution of the universe - has not been discovered and to this day it remains a theory.

But at the end of the day it is still gong to be interesting to see if they can achieve the goal of changing our understanding of physics and building on the knowledge we have from teh giants who came before us.

links on the Collider

http://public.web.cern.ch/public/en/LHC/LHC-en.html

Doomsda predictions are a few weeks off

2008-09-10T16:36:00.002+10:00

I couldn't believe my ears driving around site earlier listening to the ABC talking about Doomasady at 1830 local time tonight.

For those of you (if any suich folks exist) who do not know - tonight our time, (being Australian Eastern Std Time) engineers will attempt to circulate a beam of particles around the 27km-long underground tunnel which houses the Large Hadron Collider (LHC).

The machine, whihc cost in teh vicinity of 5 billion pounds is designed to smash particles together with cataclysmic force, revealing signs of new physics in the wreckage.

This will allegedly re-create conditions in the Universe moments after the Big Bang.

A small (but obviously very vocal) group of people believe our world will be sucked into extinction (some have even sent death threats). The majority of us, however, won't be losing any sleep.

CERN researchers have declared the final synchronization test a success and says, "The first attempt to circulate a beam in the LHC will be made this Wednesday, Sept. 10 at the injection energy of 450 GeV (0.45 TeV). The start up time will be between
(9:00 to 18:00 Zurich Time) with live webcasts provided at webcast.cern.ch tonight."

Go to this site to link into the you tube video -
http://blogs.spectrum.ieee.org/tech_talk/2008/08/switzerlands_nerdcore_scene.html

IT is great fun and tongue in cheek - just the thing to help explain experimental particle physics...

2006 SQ372 may be from the Oort cloud

2008-08-29T09:29:00.003+10:00

The other day I wrote about an interesting cometary like object presently out near Neptune - now it appears it may be an Oort cloud object. The Oort cloud is a frigid area on the outermost limits of our solar system. This cloud is a proposed reservoir of long-period comets — those that visit the inner solar system no more than once every 200 years. IT was first hypothesized to exist back in 1950.

“We believe SQ372 is the first detected member of a comet population in the outer solar system that comes from the, up-until-now, unobserved inner Oort Cloud,” says codiscoverer Nathan Kaib of the University of Washington in Seattle. “Comets like SQ372 have the potential to tell us what the entire Oort Cloud looks like, which will test theoretical models of the cloud's formation as well as provide clues about the environment that the solar system first formed in.” Kaib's team reported the findings August 18 in Chicago at a meeting on the latest findings from the Sloan Digital Sky Survey.

They suggest that this little comet may be on its return leg of a 22500 year journey. it's orbit is highly elongated and will take it back to a region about 240 billions kilometres from the Sun.

Even at its farthest point from the sun, 2006 SQ372 is only a tenth as far as the main part of the proposed Oort Cloud.

A much larger, Pluto-sized object called Sedna, codiscovered by Mike Brown of the California Institute of Technology in Pasadena in 2003, might also be a remote refugee from the inner Oort Cloud, Becker and Kaib suggest. Sedna doesn’t venture nearly as far out as 2006 SQ372 does, but it also doesn’t come as close to the sun, likely preserving more of the materials it acquired from the solar system’s outer reaches.

But of course these are all hypothesis but quite excitign if the theorectical models are true - 2006 SQ372 will have its orbit perturned by the gravitational pull of both Uranus and Neptune - but I guess we won't need to worry about how accurate our theories are as to its return in 22500 years!

TW Hya b not a planet just star spots

2008-08-26T13:54:00.002+10:00

Now this of interest to me - because that is what I am researching at present - looking at variable stars to work why they are variable and finding suitable candidtates to follow up with photometry to identify if they may have star spots and then the other guys can do their thing!

So back in January, astronomers announced that they had identified an infant planet which is the youngest yet to be discovered and is in a solar system that is still being formed. The researchers from Max Planck Institute for Astronomy in Germany reported their discovery in the journal Nature.

A Spanish team of Astronomers from LAEFF-INTA have recently sumbitted a paper asserting that the radial velocity variations are due rather to a stellar spot whihc covers 7% of the sruface of the star.

An interesting run on the 2.3M

2008-08-19T11:50:00.001+10:00

Well just finished a 6 night run on the ANU's SSO 2.3M telescope looking at a bunch of unresolved variable stars to try and find out why and then calculate their vsini for suitability for follow up by the rest of the team. The first couple of nights had a few telescope issues but was able to work around them then on Friday and Saturday the weather was crap. So I was glad we had a 6 night run because Sunday night was perfect!

Interesting comet out near Neptune

2008-08-19T11:49:00.003+10:00

Using the Sloan Digital Sky Survey, astronomers detected a small, comet-like object called 2006 SQ372, which is likely made of rock and ice out past Neptune. However, its orbit never brings it close enough to the sun for it to develop a tail.

Comet tails form when the energy from the sun boils off material

Its unusual orbit is an ellipse that is four times longer than it is wide, said University of Washington astronomer Andrew Becker, who led the discovery team.

2006 SQ372 is currently about 3.2 billion kilometres from Earth, beginning the return leg of a 22,500-year journey that will take it to a distance of 241 billion kilometres, nearly 1,600 times the distance from the Earth to the Sun. Scientists believe the object is only 50-100 kilometres across.

Apophis and 2036 - what will be the outcome?

2008-08-04T11:44:00.003+10:00

Recently, I was asked for some information about Apophis, the asteroid formerly known as 2004MN4, which has a slight chance of impacting the earth in 2036.

So, in response to that request I put together the following information which I figured would be worth sharing here with whoever it is who may read these ramblings.

Asteroid 2004 MN4 was first discovered on 19 June 2004, by Roy Tucker, David Tholen and Fabrizio Bernardi of the NASA-funded University of Hawaii Asteroid Survey (UHAS), from Kitt Peak, Arizona, and observed over two nights. It was then lost. On December 18, 2004, the object was then rediscovered by Gordon Garradd of the Siding Spring Survey in Australia.

Further observations from around the world over the next several days allowed the Minor Planet Center to confirm the connection to the June discovery, at which point the possibility of impact in 2029 was realized by the automatic SENTRY system of NASA's Near-Earth Object Program Office.

The asteroid stirred up a flurry of concern in the media around December 2004, when the risk of collision was raised temporarily to as high as 1 out of 40 for the year 2029.

Essentially, this asteroid is a smaller rock, with an estimated diameter of 1,300 feet or 400 metres, and probably won’t cause a global disaster, but will certainly “rock the planet”. Localized damage could be significant in the region struck or nearby if it hit in the ocean and a major tsunami resulted.

More precise plotting has ruled out a collision in 2029. However, Apophis will still make an extremely close pass — missing Earth by mere tens of thousands of miles. At that distance, Earth's gravitational pull could perturb Apophis' orbit enough to put it on a track to hit during another pass in 2036. The current, but still uncertain, best estimate of the flyby distance in 2029 is about twice the distance of the moon, or about 780,000 km (480,000 miles). On average, an asteroid of this size would be expected to pass within 2 lunar distances of Earth every 5 years or so.

Experts say that a 2036 impact could happen if, during the 2029 close encounter, the asteroid passes through an outer-space "keyhole" that measures about 2,000 feet or 600 metres across.

In statistical terms, the risk of an impact is now set at 1 in 5,560, based on the uncertainties surrounding Apophis' orbit.

A quarter of a mile wide and large enough to cause considerable damage, asteroid 2004 MN4 was the first asteroid in history to be ranked 4 on the Torino Scale, a measuring tool like the Richter Scale that measures the threat of space rocks.

Most of this object's orbit lies within the Earth's orbit, and it approaches the sun almost as close as the orbit of Venus. Apophis’s orbital period about the sun is 323 days, placing it within the Aten class of NEAs, which have an orbital period less than one year. It has a low inclination with respect to the Earth's orbit and the asteroid crosses near the Earth's orbit twice on each of its passages about the sun.

In an article on msnbc.com, NASA has outlined what it could do, and in what time frame, in Apophis is on a course to slam into Earth in the year 2036.

The timetable was released in 2005, by the B612 Foundation, a group that is pressing NASA and other government agencies to do more to head off threats from near-Earth objects.

The plan runs like this: In 2013, if there's still a chance of a collision in 2036, NASA would start drawing up plans to put a probe on the space rock or in orbit around it in 2019. Measurements sent back from the probe would characterize Apophis' course to an accuracy of mere yards (metres) by the year 2020.

If those readings still could not rule out a strike in 2036, NASA would try to deflect the asteroid into a non-threatening course in the 2024-2028 time frame by firing an impactor at it — using the deep impact comet-blasting probe of 2005 as a model. Experts would start planning for the "Son of Deep Impact" mission even before they knew whether or not it was needed.

Most Earth Like Planet Discovery Announced by Swiss Astronomers

2008-07-22T18:17:00.002+10:00

A team of astronomers announced they have discovered the smallest and potentially most Earth-like extrasolar planet yet. the planet which is five times as massive as Earth, orbits a relatively cool star at a distance that would provide earthly temperatures as well, signaling the
possibility of liquid water.

'The separation between the planet and its star is just right for having liquid water at its surface,' says astronomer and team spokesperson Stephane Udry of the Observatory of Geneva in Versoix, Switzerland. 'That's why we are a bit excited.'

Researchers do not yet know if the planet contains water. If it is truly rocky like Earth this might make it hospitable to life as we know it. They also do not know whether it has a thick atmosphere.

'What we have,' Udry says, 'is the minimum mass of the planet and its separation" from its
star.'"

The star red dwarf star, Gliese 581, is 20.5 light-years away from us located in the constellation Libra. Their discovery now brings the total number of planets believed to orbiting Gliese 581 to three.

Check out the article at: http://www.sciam.com/article.cfm?id=all-wet-astronomers-claim

Astronomers believe that there are many earth like planets out there - but detection of planets far enough away from their Sun and small enough to be similar to earth are very difficult with current technology to detect. This star is about 50 times cooler than our Sun and the planet orbits approximately 14 times closer so they can expostulate that favourable conditions for water may exist.

So far there are about 13 super earths ( planets with a mass of around 20 earth masses) known compared to more than 200 large gaseous planets similar in size to Saturn or Jupiter or much larger.

The Swiss team use the HARPS spectrograph on the 3.6m telescope based at La Silla, in the southern part of the Atacama desert and operated by ESO. The instrument has been operating since 2003. Since then, the team has a count of 45 candidate planets with a mass below 30 earth masses and an orbital period below 50 days.

Partial Lunar Eclipse Aug 17th 2008

2008-07-21T08:34:00.003+10:00

August 17th will see a partial eclipse of the moon at around moon set for most of us here in Australia. If you live in Africa or Europe you will see it all and if you live in the US or Canada - you will miss it entirely. West Australia will see the most of anyone in Australia.

Unlike solar eclipses, it is quite safe to watch a lunar eclipse with the naked eye - though lots of warm clothes at this time of year are essential. Watching a lunar eclipse is actually better with the naked eye than through a telescope - because as the moon is full - there is little contrast.

A Lunar Eclipse occurs when part or all of the Moon passes into Earth's shadow. This doesn't happen every Full Moon though, because the Moon's orbit is actually tipped about 5° with respect to Earth's orbit around the Sun. This means that during most Full Moon's, the Moon is actually above or below the Earth's plane and therefore not in the shadow of the Earth.

A Partial Lunar Eclipse, such as this one is, occurs when only a part of the Moon passes into the Earth's umbral shadow. This type of eclipse accounts for 30% of all Lunar Eclipses. During this phase, a "chunk" or portion of the moon goes into shadow.

The first stage, which will begin around 4:25 am is called the penumbral stage - the contrast is very subtle and the shadow can be hard to detect at first. This occurs when the moon passes through the Earth's penumbral shadow.

The partial stage will begin at around 5:35am for most of us in Coonabarabran or Sydney and continue to moonset.

Photographing eclipses is quite easy with a digital camera. Check out mreclipse.com for ideas.

http://www.mreclipse.com/LEphoto/LEphoto.html

The next total eclipse visible from Australia will be Dec 21, 2010. Then we get to see 2 in 20011 and 2012 as well.

A new Plutoid - Welcome MakeMake

2008-07-18T09:12:00.002+10:00

Last month as mentioned previously, the IAU announced a new category called plutoids at a meeting of its executive committee in Oslo. The category covers what it calls “transneptunian dwarf planets similar to Pluto”.

Plutoids orbit the Sun at a distance generally greater than that of Neptune and have a minimum defined magnitude of brightness. Makemake now joins the two other two known and named plutoids Eris and Pluto itself.

http://space.newscientist.com/article/dn14318-distant-solar-system-body-named-makemake.html

The IAU fully expects that more plutoids will be named as science progresses and new discoveries are made.

The Kuiper belt object formerly known as 2005 FY9 has now been called "Makemake”. Makemake is named for the supreme god of Rapa Nui (Chile's Easter Island).

Makemake was the creator of the first humans and the patron of the Tangata bird cult. He was worshipped in the form of sea birds, which were his incarnation. His material symbol, a man with a bird's head, can be found carved in petroglyphs on the island. With his divine power he makes the plants and animals grow. Some believe that the huge statues on the island are connected to his cult. Easter Island was first visited by Europeans on Easter Sunday 1722, exactly 283 years before the plutoid was discovered.

Makemake is now classified as both a dwarf planet and a plutoid. Makemake is fifty times further away from the Sun than we are and takes about 310 years to orbit the Sun years and has an apparent magnitude of about 16.7.

Makemake was discovered in March 2005 by astronomers at California’s Palomar Observatory. According to Mike Brown (he also discovered Eris – previously nown as Xena). He is the leader the Caltech team that found the object, they nicknamed it “Easterbunny” due to its discovery date being so close to Easter.

It had been previously designated 2005 FY9. Brown says the planet is two thirds the size of Pluto and is the brightest object in the Kuiper Belt after Pluto itself. He says the surface is “covered with large amounts of almost pure methane ice, which is scientifically fascinating, but really not easily relatable to terrestrial mythology.”

Only those in the room at the General Assembly could vote, and most who voted are not planetary scientists. Many planetary scientists do not belong to the IAU and therefore had no say in this whatsovever. One of the signatories of Stern's petition was Dr. David Rabinowitz, a member of Mike Brown's team that discovered Eris, MakeMake, and EL61.This debate is far from over. The IAU determination that dwarf planets are not planets at all makes no linguistic sense and must be reversed. Dwarf planets are simply one subcategory of the broader term planet, as are terrestrial planets, gas giants, ice giants, super Earths, hot Jupiters, etc.

Check out the ongoing Great planet debate info at http://gpd.jhuapl.edu/index.php

Amateur or Professional

2008-07-10T10:19:00.002+10:00

Sometimes this week, I have mentioned that I am a keen amateur as well as studying to be a professional. It has led to a number of conversations - not all very positive - I struggle with the difference - a simple definition is that a professional gets paid - okay - I have been employed by both the AAO and currently the ANU - I was an observer on the UKST for 13 months and have been paid over the last 2 years when I have observed on the Uppsala telescope at SSO. If I want to enter Malin's photo contest at CWAS - no doubt about it - I have to enter the semi-professional section. (that's another debate) - but when I am in my back paddock at home comet hunting if I was to find one and have it recognised - then I would be eligible for a share of the amateur prize. So, why is it when I mention that a fair bit of work on my thesis will be based on work done on my 12" from home - do people consider that amateur and appear to look down on such things.

I will also use data obtained from the ANU 1M and 2.3M telescopes - that is all right of course - because they are professional telescopes. Doesn't make the overall quality of data collected from them any better just different - I have seen some pretty data data obtained from so called professional telescopes and some amazing data from so called amateur gear and non professional astronomers.

I have no answer - at the end of the day or night - I am an astronomer - one who studies astronomy, the stars and the physical universe - and I am one whose major area of research is astronomy and astrophysics.

Einstein and General Relativity live to fight another day

2008-07-06T00:42:00.002+10:00

Science News reports that General Relativity has passed yet another test. One of things being discussed this week at the HWWS I have been attending relates to gravitational waves and whether Einstein's GR theory actually works outside of the earth environment.

In 1915, in his Theory of General Relativity, Einstein predicted that in a close system of two very massive objects, such as neutron stars, one object's gravitational tug, along with an effect of its spinning around its axis, should cause the spin axis of the other to wobble or precess. Over the years there have been studies which have shown that such wobbling does occur but they have been unable to have precise measurements as to the amount of wobbling.

The system that was used to test GR was a pair of neutron stars which are unique in that of the 1700 plus known pulsars these are the only binary system. The two pulsars orbit each other and hence produce a very strong gravitational field. Also, of significance is that the orbital plane of these two pulsars is aligned with earth so eclipsing events can be monitored from here. Scientists from McGill University used the Green Bank Telescope to do a four year study of the system.

"A system like this, with two very massive objects very close to each other, is precisely the kind of extreme "cosmic laboratory" needed to test Einstein's prediction," said Victoria Kaspi, leader of McGill University's Pulsar Group. Theories of gravity don't differ significantly in "ordinary" regions of space such as our own Solar System. In regions of extremely strong gravity fields, such as near a pair of close, massive objects, however, differences are expected to show up.

In the binary-pulsar study, General Relativity "passed the test" provided by such an extreme environment, the scientists said.

1500th Comet for SOHO

2008-06-30T20:45:00.003+10:00

So why is SOHO, the Solar and Heliospheric Observatory, which was designed to study solar physics doing looking for comets? In so many ways it is just literally in the right place between us and the Sun so it can see those places near the Sun it is impossible for us to see from Earth.

On June 25th it discovered it's 1500th comet it was announced by ESA last Saturday.

So, how does it all work? The cynic is me remembers the diligent dedicated computer whiz kids who set up their computer programs running and checking every new image downloaded to be the first to announce their discovery.

Must confess, there are times that the purist in me, can be sorely tempted on a frosty pre-dawn morning as I visually survey the south eastern skies.... though I do confess to checking the images as c2006/P1 McNaught burst into all its glory and out did Venus back in January 2007.

On laser pointers

2008-06-23T14:28:00.004+10:00

Just read the changes to the Summary Offences Act which make laser pointers a dangerous implement. It was given assent by the Legislative Assembly on the 20th June after it's third reading and return by that house to the lower house. Supported by all parties.

The definition of a laser pointer in the bill means a hand-held battery-operated device, designed or adapted to emit a laser beam, that may be used for the purposes of aiming, targeting or pointing.

It further states:

Schedule 2 [2] provides that it is a reasonable excuse for a person to have custody of, or use, a laser pointer if the custody or use is reasonably necessary in all the circumstances for the lawful pursuit of the person's occupation, education, training or hobby. It is also a reasonable excuse for a person to have custody of a laser pointer during travel to or from or incidental to that occupation, education, training or hobby

http://www.parliament.nsw.gov.au/prod/parlment/hansart.nsf/8bd91bc90780f150ca256e630010302c/e86bbee1d2511fb2ca25746d0008da75!OpenDocument is the link to Hansard and the whole speech

There is nothing in there about a permit - it would appear you need to be able to prove to the police's satisfaction that you are doing the right thing and have an appropriate reason to carry and use the device. This appears to be similar to the situation with knives - I carry a leatherman around the farm and at work as a tech support person - I have a legitimate reason - if I am at the Opera or something in Sydney and get caught with it during an affray - I better have a real good reason.

You can read the draft of the Bill here: http://www.smh.com.au/multimedia/pdf/laserpointersbill-summary.pdf

In Hansard, in the lower house readings on 13th June when teh bill was being passed to the Legislative Assembly - the Police Minister, Mr David Campbell is quoted as follows:

" thank all members who have contributed to debate on the Summary Offences and Law Enforcement Legislation Amendment (Laser Pointers) Bill 2008. Significantly there has been a concern about what amateur astronomers may or may not be able to do. Notwithstanding the critique of my agreement in principle speech by the member for Wakehurst, I did make it clear that an amateur astronomer, a teacher, a lecturer, an architect or a builder would have a legitimate and lawful excuse to use a laser pointer. I make it clear that the Government's intent is to exempt anyone who is a member of an astronomical society. I also make it clear that in preparing this bill I made sure that the Ministry for Police consulted with the New South Wales Astronomical Society, and I understand that consultation occurred with Mr Les Sara.The permit process is being developed and we intend to ensure that information is circulated to all societies regarding an exemption that will be available to them and what they need to do to formalise those permits. It is important to make that point, particularly following the contributions of the member for Murray-Darling and the member for Dubbo. I note that the member for Dubbo raised the concerns of astronomers, particularly those associated with the Parkes Observatory and those involved with the Central West Astrofest, which I am sure is an important community festival in the central west. I noted that the member for Epping made the comment that the Government is right, which I very much appreciate in the context of this debate."

So, as I see it - and this is just my 0.02 worth - if you are doing the right thing - you're fine - maybe astronomy clubs need to do up membership cards for the members or something that can identify them as such - and since a lot of us do a lot of public outreach this may not be a bad idea anyway. As my old dad says - the bad guys will do the wrong thing regardless of the law - it is only the good guys that suffer!

Pluto having another Identity Crisis?

2008-06-20T14:07:00.004+10:00

Have you heard -----

The IAU, it appears has decided on a new term to describe Pluto and some of its fellow dwarf planet mates! The term is "plutoid" .

It is two years since Pluto and the other dwarf planets were given their new status. Now it seem Pluto and Eris at least are to have a new class of their own!

Here is the new definition: (from the IAU release of June 11 2008)

"Plutoids are celestial bodies in orbit around the Sun at a semi-major axis greater than that of Neptune that have sufficient mass for their self-gravity to overcome rigid body forces so that they assume a hydrostatic equilibrium (near-spherical) shape, and that have not cleared the neighbourhood around their orbit. Satellites of plutoids are not plutoids themselves, even if they are massive enough that their shape is dictated by self-gravity. The two known and named plutoids are Pluto and Eris. "

Now poor old Ceres will not be a plutoid as he lies between Mars and Jupiter and since they believe he is one of a kind - I wonder if he stays as a dwarf planet or goes back to being the Asteroid we all have known and loved or even a planet as the ancients considered!

Read it all for yourself

http://www.iau.org/public_press/news/release/iau0804/

The Position of the Moon in the Southern Winter Sky

2008-06-20T10:36:00.003+10:00

Got asked a question today about why the moon appears so far North at present - so since I had to write a response thought I would it post it here to be pulled apart by all.

Although most people seem to know that the position of the rising and setting Sun changes during the course of a year, as does the Sun’s height at noon vary in relation to the horizon dependent upon the seasons. In winter, the Sun rises in the southeast and sets in the southwest, while in summer it rises in the northeast and sets in the northwest, obviously spending more time in the sky than during winter. At the spring and autumn equinoxes the sun rises at due east and sets and due west and the length of day and night are the same. The points at which the Sun is at its greatest distance from the equator are called the solstices. The solstices mark the longest and shortest day of the year. The longest day of the year is the summer solstice, and the shortest day is the winter solstice.

The imaginary line which the sun follows through the heavens is called by astronomers the "ecliptic". The sun takes one year (365.25 days) to complete one journey around the sky along the Ecliptic. At the same time the earth is tilted 23.5 degrees from its axis of rotation and this is the only reason we have our four seasons. Where the moon crosses the ecliptic moving northward, is called the ascending node and where it crosses it moving southward is called the descending node. These two nodes are always located 180 degrees apart, or at opposite sides of the sky to each other. It takes the Moon just 14 days to make the journey from one node to the other, but it takes the Sun six months to make a similar 180-degree trip through the sky. The nodes themselves slowly move through the sky, so that the Moon's intersection with, and maximum separation from, the Ecliptic move through the constellations slowly over time. This movement is westerly, taking the rotation of the nodes in the opposite direction of the Moon's movement through the stars, which is from west to east.

Perturbations to the moons orbit , mainly from the sun, cause the position of the nodes to shift slightly or regress every year. The nodes will return to their original positions every 18.6 years. This is node to node and called Draconic as it is related to eclipses and according to some cultures eclipses happen when a dragon eats the Moon. The draconic cycle can increase or decrease how far the Moon is north or south. The Moon is currently almost at the northern most point of its orbit which is about 4 degrees more northerly than usual.

The 12 so called Zodiac constellations are those through which the Sun, and the planets, passes through on their journey through the sky. However, while the planets follow the general path of the Ecliptic (or the Sun’s path), the Moon does not. The line formed by the Moon's course on its 29-day journey (lunation) around the sky is tilted slightly towards the Ecliptic. This means that, while the and Sun's path (Ecliptic) intercept twice during one lunation, its path is tilted slightly so that it separates from the Sun's path by a maximum of about 5 degrees which is roughly 10 moon widths to the observer on Earth.

Clouds in the West and a glimpse of C/2007 W1

2008-06-08T18:24:00.002+10:00

Well looks like it will be the books again this evening as the clouds in the west will make observing a pain - had a quick glimpse of Comet Boattini and will try again in a little while after dinner before it sinks behind Mopra....

C/2007 W1 Boattini Observing

2008-06-08T12:43:00.001+10:00

Been checking up most nights on C/2007 W1 Boattini which is looking really good in binoculars and except for the poor seeing that seems to make all things look like comets at times great naked eye. It is easily about 4-4.5 magnitude at present under the dark skies. I intend to go out again tonight and tomorrow night and check it out as it travels through Canis Major.

Andrea works at Mt Lemmon and is part of the Catalina Sky Survey team while, on occasion I work with Rob McNaught and Gordon Garrard on the Southern Part of the team at Uppsala.

Getting ready for Exam Time!

2008-06-08T12:18:00.000+10:00

Well supposed to be studying so why am I writing on my blog? Because I really struggle with the subject of statistics - who cares about the null hypothesis and p value in the real world! Still, have to pass to get my Masters - this should be my last exam and all the rest of the subjects are research based. Exam is on the 18th and have a project due on the 27th as well so had better get on top it all.

Have purchased the materials to get the observatory started - still totally confused as to what sort of roof to use. Need to do some tests as to whether the 6 foot high walls need to be hinged so that I get full visibility.

Had a great visit with Dick Shamrell from Clarke College Vancouver USA last week - it is really good to meet up with astronomers from all over the world.

Did my presentation for Research Practices and Ethics last week and submitted it - waiting to get results back as I really need to get some feedback as that is what I am going to use as the basis of my poster paper for ASA/HWWS conference next month in Perth.