Caelumnoctu

Chris Lintott (him of Sky At Night stardom) reports that Asteroid 57424 (or 2001 SP22) has been given the name Caelumnoctu in honour of the long running, British TV series. In case you were wondering about the name, Caelumnoctu comes from the Latin words caelum (sky or heaven but also an obscure southern constellation) and noctu (night). Apparently this was announced at the 50th anniversary party that was held the other night at Patrick Moore's home. Here's to another 50 years!

Aside: I was amused to discover that Technorati thinks there is "Nothing in the known universe tagged Caelumnoctu". Hopefully that situation should change now.

Posted in astro blog by Stuart on Friday 27th Apr 2007 (00:48 BST) | Permalink

Earth-like planet found?

I'm just reading a European Southern Observatory press release about a potential planet that is 1.5 times the diameter of the Earth and five times the mass. There are some things about it that are niggling me so I'll write more when I've actually read the paper that the discoverers are planning to submit as a Letter to Astronomy & Astrophysics. In the mean time, the Bad Astronomer and News in Space (MP3: 32.6 MB) have their takes on the news.

Update (11:50 BST): I've now read the paper which hasn't been accepted yet (that doesn't mean it won't be!). One of the things in the press release that concerned me was the statement that the radius of the planet was 1.5 that of the Earth. The reason for my concern is that this planet (and the others around the same red dwarf star) were found using the radial velocity method whereby the changes in velocity of the parent star are monitored. This method can only tell you the periods of planets around the star. However, using the period, the size of the change in velocity, and Kepler's laws you can work out the mass and size of the orbit. This still doesn't give you the physical size of the planet. To do that you either need the planet to pass infront of its parent star or to know the composition (rocky, gas etc) and make a guesstimate at the size from mass and density. In this case, the authors have relied on a paper by Valencia et al (2006) which makes various assumptions to get a relationship between the mass of 'super-Earths' and their sizes. So the 1.5 Earth-diameter figure relies on this model being valid for a planet forming near a red dwarf star. It may be fine but I'd like to wait to see.

The other thing I'm slightly confused over are the final masses (why no uncertainties on these?). The quoted masses seem to be the minimum masses that the planets could have and the true mass depends on the inclination of the orbital planes. So, they could be larger. Having said all this, it is good to see that the authors have considered other possibilities to explain their data. For instance, they considered large sunspots on the star. In the end they dismiss these because other measurements show the star to be quite inactive.

Posted in astro blog by Stuart on Wednesday 25th Apr 2007 (10:42 BST) | Permalink

Wow!

The Hubble Space Telescope is celebrating 17 years of operations with a truly fantastic image of the Carina nebula. Take a look (click image for larger versions)!

Carina nebula
Hubble Space Telescope view of the Carina Nebula which is 7500 light years away. Image composed of 48 frames from the ACS. Red is sulphur, green is hydrogen and blue is oxygen. CREDIT: NASA, ESA, N. Smith (University of California, Berkeley), and The Hubble Heritage Team (STScI/AURA)
The full size image totally blew me away but it gets even better when you zoom in and have a look at the star clusters, Bok globules, star formation regions and shocks. I could spend hours looking around this image just exclaiming at the shear beauty of it and finding gems. The full sized image is a mosaic created from 48 separate images taken by the Advanced Camera for Surveys - which broke at the end of January - and consists of a whopping 29,566 x 14,321 pixels. It covers a region about 50 light years across and is false colour; red represents sulphur, green shows the hydrogen and blue is the oxygen. Watch the latest Hubblecast video for more details.

I have tried printing out a lower resolution version (although still huge) but the printer I used washes out the colours so it looks as if I have spilt water all over it. I would love to see this wall-sized from a good printer. Anyway, here are a few close-ups.

Carina close-up
Caring nebula close-up CREDIT: NASA, ESA, N. Smith (University of California, Berkeley), and The Hubble Heritage Team (STScI/AURA)

Carina close-up
Caring nebula close-up CREDIT: NASA, ESA, N. Smith (University of California, Berkeley), and The Hubble Heritage Team (STScI/AURA)
The image above shows a close-up of one region containing an open cluster with Bok globules looking amazing silhouetted against the rest of the nebula. Another area of the full image (below) shows the star Eta Carina (bottom right) itself with its two lobes of material that it ejected around 150 years ago. The area next to it looks pretty circular and I can't help think that it is some kind of shock front from another star.
Carina close-up
Caring nebula close-up CREDIT: NASA, ESA, N. Smith (University of California, Berkeley), and The Hubble Heritage Team (STScI/AURA)
There is a huge amount of really interesting physics going on in this image but, for now, I'm just going to sit and be awed.

Posted in astro blog by Stuart on Tuesday 24th Apr 2007 (14:00 BST) | Permalink

Cheap binoculars

This is just a heads up for people in the UK. Via a friend I have discovered that the LIDL chain of supermarkets is currently selling Bresser (part of Meade) 10x50 binoculars for 10 of your Earth pounds. For only £10 they are really good and worth getting (I've just bought a pair) but I suspect they may sell out pretty quickly.

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Posted in astro blog by Stuart on Tuesday 24th Apr 2007 (12:30 BST) | Permalink

Is Zeus a planet?

In case you were on another spherical object last summer, you were probably aware of the debate over the definition of a planet. In this debate, Pluto has been seen widely to have been "demoted" to dwarf planet status. The word "demoted" has been used often as if Pluto has stopped existing or has had its pension rights removed. Before the debate I was quite happy for Pluto to remain a planet and even admit some new members to the the planet club based on a definition such as "spherical equilibrium". However, the ensuing debate and the apparent emotional response has left me caring very little about what is and what isn't a planet. Ultimately, this is an issue of semantics and doesn't affect the reality of what Pluto, Eris, Earth or Jupiter are actually composed of or how interesting they are.

One of the things that has come out of all this is the emotional attachment, anger and upset that many people have over Pluto (I can't help thinking that there are far more important things for people to worry about on Earth than what we call Pluto). Perhaps some of the attachment to Pluto is due to the name. After all, Disney was quick to use the name for a popular cartoon dog and that must be built into the conciousness of many people in the western world. What if Pluto was not named Pluto? What if Venetia Phair had been ignored and some of the original suggestions had been used? Would we have a Society for the Preservation of Zeus as a Planet? Would anybody start a petition to save 134340? Would New Mexico have made a declaration that Constance is a Planet when over its skies? Does alliteration help Pluto's cause? Can I ask any more rhetorical questions?

Pluto and its three moons are hugely interesting. I no longer care if it is a planet or dwarf planet. It is Pluto.

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Posted in astro blog by Stuart on Tuesday 24th Apr 2007 (12:21 BST) | Permalink

AGILE launched!

I hear that the Italian space mission AGILE was successfully launched from India at 12:00 CEST. AGILE (I think this is pronounced a-jee-lay) is an X-ray and gamma-ray imaging spacecraft which is considered to be like a bigger version of EGRET or a smaller version of NASA's GLAST spacecraft (due for launch no earlier than December this year). Buona fortuna AGILE.

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Posted in astro blog by Stuart on Monday 23rd Apr 2007 (16:09 BST) | Permalink

NAM 2007 in the pod

I've already excused my lack of blog posts from the National Astronomy Meeting and the reason has partly been the time (and effort) I've put in to podcasting the week. Days one to four are now online in special daily shows.

We covered a huge range of topics including: International Heliophysical Year (Lucie Green), meteorites (Monica Grady), wakes left by moving stars (Chris Wareing), the effects of solar radiation on astronauts (Mike Lockwood), magnetic bubbles/force-fields (Ruth Bamford), the Herschel Telescope (Matt Griffin), the Hubble Space Telescope and World Space Observatory (Martin Barstow), astro-chemistry and the Sky At Night (Chris Lintott) and exoplanets (Peter Wheatley). The final day (day 5 which was today) will be released tomorrow and contains interviews about STEREO (Chris Davis), Mars Express (Helen Walker) and RS Ophiuchi (Mike Bode).

Some of the interviews were recorded in the University of Central Lancashire's recording studios and others were recorded in the lecture theatres, corridors and poster sessions. Personally, I like to have some of the background noise because it puts across some of the feel of the conference. Thanks to David Boyce, Paul Steele and Neil Phillips who joined the standard Jodcast crew to help with presenting duty and get a broader view of the many parallel sessions.

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Posted in astro blog by Stuart on Friday 20th Apr 2007 (22:43 BST) | Permalink

NAM Bloggers

I have been really busy over the past few days and the wifi connection at the National Astronomy Meeting has been a bit flaky so I haven't been able to do much online. However, I have noticed that there are other NAM bloggers out there so I'll put some links to them here. Some of the blogosphere are in attendence and include Orbiting Frog (appears to be a PhD student from Cardiff), Chris Lintott (co-presenter on the Sky At Night), Megan and David Boyce (he is helping podcast NAM).

I'll also add that I'm "micro-blogging" the NAM on Twitter for the Jodcast.

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Posted in astro blog by Stuart on Wednesday 18th Apr 2007 (11:16 BST) | Permalink

ELTs phone home

In my first NAM post I mentioned Extremely Large Telescopes (ELTs). These have been proposed by several nations and even groups of nations such as Europe. They were previously known as OWLs (Over-Whelmingly Large Telescopes) although that name seems to have fallen out of favour and the proposed sizes are no longer quite so over-whelming as the original 100 m (328 ft) diameter. So, I decided to go to the National Astronomy Meeting session on ELTs to find out what the current status of the European effort is.

The European design and technology program is now aiming at a 30-60m diameter telescope with a baseline of 42 m (the answer to life, the universe and everything crops up everywhere!) and a "large" field of view of about 5 to 10 arc minutes (one sixth to a third the angular size of the Moon).

So why do we want huge telescopes? Firstly, the increased collecting area gives the ability to look at fainter objects and, secondly, the increased diameter gives better resolution. Significantly improving these two aspects opens up some new areas of study. For instance, it will be possible to directly image faint exo-planets from their companion star and it should also be able to detect planets with masses as low as the Earth with the radial velocity method.

New study won't just be limited to established planets though as an ELT will be able to image proto-planetary discs where solar systems are forming. On larger scales, and ELT will be used to explore the physics of how galaxies form. Other interesting things that it is hoped to study include dark energy by observing the spectra of Type 1a supernova to huge distances (z~4), variation in fundamental physical parameters in the universe and the physics of black holes.

There are at least two reasons why such large optical telescopes have not been built so far. The most practical problem is the sheer amount of engineering require to build a structure so vast and yet so precise. It will need to point to anywhere in the sky and also withstand earthquakes and wind which will make the whole thing sway. The current European design will oscillate at a rate of 2.1 Hz (with a wind speed of 10 m/s) which one of the speakers - Guy Monnet - pointed out will lead to a wobble of the image of around 1 arc second. This will need to be corrected for.

The other major limiting factor is the Earth's atmosphere. It sits in front of every ground-based telescope wobbling away and distorting the images. In recent years this limitation has started to be corrected for on large, professional telescopes using adaptive optics. However, that doesn't mean that the problem is solved because it becomes a much harder task as you make your telescope larger.

So where might it be? An ELT site needs clear skies (lacking in clouds, dust, contrails etc), the atmosphere has to be suitable for adaptive optics, and it needs to be suitable from a geographical, economical and political point of view (astronomers need to be able to get in and out of the country to be able to observe). A decision on the site may happen by the end of 2008.

So what does the future hold? Well, there is a lot of work being put into this but we aren't going to see anything for at least 10 or 15 years.

I'll finish with a great quote from Guy Monnet who said (in reference to ELTs):

"It has gone from being enormous to being half enormous"

Posted in astro blog by Stuart on Tuesday 17th Apr 2007 (10:07 BST) | Permalink

NAM public talk NOW

In case anyone is out there in Internet-land right now, there is a live webcast of Astronomy Question Time. It will have Chris Lintott, Jocelyn Bell-Burnell and possibly Lucie Green. Check out the wmv feed (although I don't seem to be getting it).

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Posted in astro blog by Stuart on Monday 16th Apr 2007 (19:39 BST) | Permalink

NAM Blogging Live!

NAM is the UK's National Astronomy Meeting and this year is in Preston. I've now had it pointed out by at least three people that this blog is unfortunately ranked higher on Google for "nam 2007" than the real NAM site. The Jodcast team are here for most of the week and will be recording interviews with some of the astronomers that are here. I'll be trying to keep the blog up-to-date too. As full blog entries take a bit of time to type, I'll also be keeping a micro-blog on twitter for the Jodcast.

The first talk of the conference was a plenary session given by Tim de Zeeuw from Leiden Observatory (I think). He talked about the Sauron Project which did imaging spectroscopy so that you can find out the chemical and velocity information of all parts of the object you are looking at. Some of the galaxies they've looked at were really bizarre with counter-rotating discs and even a galaxy which appears to have the gas rotating in a plane at 90 degrees to the stars. Bizarre!!

I missed the afternoon tea break to talk to Lucie Green about the International Heliophysical Year (IHY). We got to use a real recording studio for once (but using our own new mics and recorders). The echo is virtually non-existent so the sound quality should be great.

I'm now in a session about Extremely Large Telescopes (ELT). There are only around 20 people in this session because there are three other sessions happening in parallel. Guy Monnet is talking about the history of telescope sizes and why (and how) we need bigger telescopes. Amongst the other problems, big telescopes - 30, 50 or 100m - need new technology to help keep the weight down.

Earlier I also bumped into David Boyce - a PhD student from Leicester - who keeps an excellent blog which we updates nearly every day.

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Posted in astro blog by Stuart on Monday 16th Apr 2007 (16:01 BST) | Permalink

Black hole eclipse

Head over to Tom's Astronomy Blog for a post about Chandra observing an eclipse caused when a dense cloud of gas passed in front of the disc surrounding the supermassive black hole at the centre of NGC 1365 (it is a large, barred spiral galaxy in the direction of the Fornax cluster of galaxies). This is really cool because you can work out the size of the disc of material feeding matter into the black hole. It turns out to be about 2 billion times smaller than the galaxy - which is 160,000 light years across according to Wikipedia - and about 10 times larger than the size of the expected event horizon.

You can hear about this on the Science@NASA podcast - Black Hole Eclipse (MP3: 1.3 MB).

Posted in astro blog by Stuart on Friday 13th Apr 2007 (11:37 CEDT) | Permalink

Chinese Lunar Rover

The BBC have a story that engineers at the Shanghai Institute have unveiled a new prototype rover. This is nothing to do Longbridge - that is a different type of Rover - but instead refers to a rover which may end up as part of a Chinese mission to the Moon in 2012. Here is the accompanying picture.

Chinese lunar rover
Prototype for a lunar rover being displayed at the Shanghai Institute CREDIT: Reuters
I must admit that, like cars, planetary rovers appear to look very similar these days. They all seem to have gold foil bodies, solar panels spread wing-like, six wheels, and stereo cameras on a mast. For instance, compare this new prototype to the Spirit rover or ESA's proposed ExoMars rover (although ExoMars is starting to look a bit more like Jonny 5). I guess that once you've found a practical design you stick with it.

Another interesting thing I noticed in the image above is the presence of the Open University's Prof John Zarnecki (left-most of the group of three). Prof Zarnecki was the principle investigator on the Huygens Surface Science Package (landed on Titan) and is also the principle investigator for the UV spectrometer on ExoMars, so it makes sense for him to be visiting and perhaps sharing ideas.

Posted in astro blog by Stuart on Monday 09th Apr 2007 (11:43 BST) | Permalink

STEREO animations

STEREO consists of two spacecraft that between them will make three dimensional images of the Sun and was launched last year. Back on the February Jodcast we talked to Chris Davis (MP3: 4.5 MB) of the STEREO mission about current progress. The spacecraft are not yet in position but they are on their way and producing some early results. A few weeks ago I somehow missed the news (although Tom, Phil and everyone else didn't) about the amazing video the STEREO team have released showing the Earth's Moon passing between the "behind" spacecraft and the Sun. It is just stunning. More recent news is that Ian has an animation of Comet Machholz seen by STEREO. I may be late to the party but all these animations are worth it.

Posted in astro blog by Stuart on Sunday 08th Apr 2007 (17:03 BST) | Permalink

Exoplanet count

Over at PlanetQuest (maintained by the Jet Propulsion Laboratory) the current planet count is standing at 204 following the recent announcement of four more gas-giant planets around the stars HD 219828, HD 100777, HD 190647 and HD 221287 all of which are between 170 and 260 light years away. However, that number disagrees with my preferred planet counter; the fantastic Extrasolar Planets Encyclopaedia (EPE) maintained by Jean Schneider of Paris Observatory. That is currently reporting a total of 218 candidate planets (as of 7th April 2007). One of the cool features of the EPE is that, as well as giving you the low-down on each new candidate, it splits them up by detection method. So, for instance, you can see that an amazing 206 of the 218 candidate planets have been found using the radial velocity method.
Of course planets are all very well and good but sometimes I want to know how many moons various solar system bodies have. For those answers I use Scott Sheppard's excellent satellite count page. Saturn is up to 56 moons now and with Cassini still spotting them, it may exceed Jupiter's 63 known moons!

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Posted in astro blog by Stuart on Sunday 08th Apr 2007 (16:43 BST) | Permalink

NAM 2007

In just over a week's time, the UK National Astronomy Meeting (NAM) will be taking place at the University of Central Lancashire in Preston. NAM is a bit like the UK equivalent of a AAS meeting bringing together astronomers from all over the UK as well as a few from overseas. In total there are around 480 people currently registered for the event with over 400 abstracts submitted for talks and posters. Bizarrely, my dad got talking to someone on a plane the other day who turned out to be an astronomer from Hawaii who will be attending NAM. This planet can seem very small sometimes!

Anyway, I'm going to be at NAM for the full four or five days and I'll be trying to do as much live blogging and podcasting as is humanly possibly. If anyone else out there in the blogosphere is going, let me know and I'll make sure I link to you during NAM.

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Posted in astro blog by Stuart on Sunday 08th Apr 2007 (11:20 BST) | Permalink

AMP improvements

Near the end of last year I created the Astronomy Media Player as a way to bring astronomy podcasts together. Since then, the number of astronomy podcasts has grown quite a lot and the list on the front page of the AMP is no longer big enough to include everything - especially after adding a few more today (thanks Ed). In an effort to include everything and group the podcasts by topic, I've created a new front page for the AMP. The new layout was inspired by a popular podcatcher and it has taken me the best part of this evening to get it all working. It should work in Firefox and Internet Explorer 6. It would be great if people would give it a test (especially with other computers/browsers) and let me know what you think. If it doesn't cause any problems and people think it is an improvement, I'll make it the real front page.

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Posted in astro blog by Stuart on Saturday 07th Apr 2007 (02:41 BST) | Permalink

50 years backwards, 50 years forwards

If you're in the UK (or can watch BBC1 some other way) check out the 50th anniversary episode of the Sky at Night tonight at 11.30pm. The episode is titled "Time Lord" and that evokes images of that other great (and traditionally low budget) BBC programme Doctor Who. The April episode transports Patrick Moore back into 1957 to talk to his younger self (played by the great Jon Culshaw according to Chris Lintott) and then into 2057 to talk to a virtual Patrick and rather old looking Brian May and Chris Lintott. Chris says (assuming it isn't an April fool) that the virtual Patrick will resemble his incarnation in the early nineties Channel 4 programme Gamesmaster which will be great to see. The idea of this time travelling is to see how much astronomy has changed since the dawn of the space age and how it might change in the next 50 years. It sounds as though this episode will be a lot of fun.

It will be repeated tomorrow night on BBC4 and next Saturday on BBC2. For those without access to UK TV, you should be able to see it on the website archives in a week or so.

Posted in astro blog by Stuart on Sunday 01st Apr 2007 (16:41 GMT) | Permalink

Gravity waves and quasars

At midnight (UTC) the April edition of the Jodcast went live and you'd be a fool to miss it. We re-visited the topic of gravitational waves by talking to Dr Graham Woan, of the University of Glasgow and even hearing the 'sounds' that they might make. Dr Woan is part of the team behind the GEO600 detector near Hannover and he is part of the LIGO Scientific Consortium. The gravitational wave folks seem to be nudging closer and closer to actually being able to detect the tiny effects of gravity waves passing by; it is quite exciting. There is also an interview with Prof Steve Rawlings of Oxford about quasars and the black holes that are thought to be at their centres.

Between 16th and 20th April the Jodcast team shall be heading over to the National Astronomy Meeting in Preston. It is a much smaller, UK-equivalent, to the annual AAS meeting and the Jodcast will be podcasting it. I'll try to blog it too if I get chance.

Posted in astro blog by Stuart on Sunday 01st Apr 2007 (11:25 BST) | Permalink
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