Herstmonceux Astronomy Festival 2008 lecture
I’m very pleased to announce that I will be giving a talk at this year’s Herstmonceux Astronomy Festival, held at the famous Herstmonceux observatory in Sussex. The subject of my talk will be the science behind the Hubble Space Telescope’s greatest images. To find out more about the festival, which will be held on the 5th, 6th and 7th of September, visit the Observatory Science Centre’s website here.
Hubble’s magnificent mergers
OK I admit it. Galaxies are my favourite objects that the Hubble Space Telescope studies and images. But it’s true; there’s something so awesome about the HST images that ooze detail in a way that captures the vast and magnificent nature of these ‘stellar cities’. But it’s not all about the pictures. Hubble has allowed scientists to see the farthest galaxies in the Universe, that also happen to be some of the earliest too. Those observations have given us a real insight into how the galaxies we see today form. Hubble has studied Cepheid variables in distant galaxies too, allowing us to make accurate distance measurements of far off galaxies.
Today the Hubble team have released the most stunning collection of galaxy images I have ever seen. Fifty nine images in total showing many galaxies merging. What’s fascinating is that you can piece together a rough idea of how a merger takes place, out of several images of different ‘collisions’. This isn’t unusual. Astronomers do it all the time. If you wanted to see the lifetime of a Sun-like star you obviously wouldn’t hang around for 10 billion years to watch it from start to finish. What you do is look around the Universe for different Sun-like stars at different points in their life. We can do this now to get at a very basic overview of how a galaxy merger unfolds.
The above image is made from six separate images of differing collisions. Yet put together they show the progression of a galaxy merger. In reality a galaxy collision is a slow and stately affair. In fact during galaxy mergers the stars within the galaxy generally don’t smash together. That’s because of the vast distances between stars; however some stars will ultimately be thrown from the galaxies out into the depths of space.
Over millions of years the gravity of the galaxies begins to twist and shape streams of stars. In the first panel you can see the left hand galaxy is slowly starting to deform as the two galaxies begin to interact. Emerging from the lower left of the left galaxy is a noticeable stream of stars – the first sign that a merger is underway. In the second panel the merger is further along. Here much bigger streams, called ‘tidal tails’, extend out from the galaxies as the two get ever closer. In the third panel the merger is advanced even more with a massive bridge of millions of stars stretching between the two galaxies’ cores. In the last three images the mergers show dramatic twisting and swirling shapes. As the collisions of clouds of dust and gas take place, shockwaves travel through the galaxies. This results in a staggering burst of star formation (note the young blueish stars in the fourth image). Eventually the two galaxies will become one – usually a enormous dusty elliptical galaxy.
To see the full catalogue of the Hubble merger images view the press release here and of course you can watch the latest episode of the Hubblecast about the images here.
First image credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and K. Noll (STScI). Second image credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University), K. Noll (STScI), and J. Westphal (Caltech). Third image credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University)
BBC Sky At Night magazine podcast now on iTunes
What the title says really. For those of you that want to subscribe it’s on iTunes here.
BBC Sky At Night magazine podcast released
Our new podcast is now out on its very own webpage here. In the first episode Sky At Night magazine’s editor Graham Southorn and I chat about the Royal Astronomical Society’s National Astronomy Meeting that I visited a few weeks ago.
If you listen to the podcast you can also find out what James Bond has been doing at one of the world’s largest observatories (the VLT in Chile), hear about the latest on the plans to upgrade Hubble this summer and the discovery of the youngest extrasolar planet ever found.
Where do comets really come from?
I have a new feature in May’s BBC Sky At Night magazine (out in the shops early next week) entitled “Where do comets really come from?”. It’s about how new results from the NASA Stardust mission are unveiling new insights into the origin of cometary material.
Left: Comet Wild 2. Credit: Stardust/JPL/NASA
International Year of Astronomy 2009 trailer
Turn up the sound on your computer, get ready and watch this! It’s a new trailer for the International Year of Astronomy 2009. Very cool indeed. The Year is fast approaching and there will be lots happening around the globe. If you haven’t got any ideas on what to do (but want to get involved) contact your national node, get some ideas from here and get involved!
Credit: International Year of Astronomy 2009, IAU and UNESCO
P.S. another new site definitely worth a look is the new International Astronomical Union website. There’s a wealth of information on there. Especially make sure to check out the ‘themes’ section – it’s the definitive IAU reference for lots of subjects like naming stars, classifying planets and much more. Oh and if you want the HD version of the above trailer be sure to get it here.
Cassini gets go for two more years
It was great to see this news drop in my inbox this morning. Firstly because (in my opinion) the Cassini-Huygens mission is one of the most important planetary missions ever undertaken by humankind but also because it gives me the excuse to put up one of Cassini’s dazzling images on the blog.
The Cassini-Huygens mission has given us views of another planet and its moons like no other spacecraft has and I’m routinely mesmerized by the views it sends back, let alone what its scientific instruments are telling us. It’s incredible to think that in the last six months Cassini has found evidence of: an ocean underneath Encealdus’s surface; a system of rings around Rhea and even organic material in the geysers on Enceladus.
Above is my favourite recent image from Cassini. It shows Saturn when it was 2.6 million km from Cassini. You can also see four of Saturn’s moons – Tethys, Mimas, Janus and Pandora. If you can’t spot them in the above image then have a scan around the stunning full resolution one available here.
Image credit: NASA/JPL/Space Science Institute
The Carnival of Space no. 49
Hello and welcome to the 49th Carnival of Space. I’m really pleased to be hosting the carnival this week as we have some brilliant stories for you, thanks to some great writers and bloggers. This is where after a week of hard work you can now sit back and get your full dose of astronomy related news and views, finding out what the blogosphere has had to say about the Universe, in the last week. Don’t forget to check back soon and subscribe to the RSS feed on the right to keep up-to-date with the site. So, without further delay let’s begin…
The start of this week’s carnival takes on a distinctly stellar theme. Fraser at Universe Today responds to a superb astronomical question from his young daughter that I am sure we have all wondered about at one point or another.
Towards the end of March a massive Gamma Ray Burst (or GRB) was seen in the night sky. It was the brightest most distant GRB to date and one that was so bright it was visible to the naked eye! Dr. Ian O’Neill on Astroengine asks whether a peculiar type of star called a ‘Wolf-Rayet star’ could be responsible.
Complementing this nicely, Ethan at Starts With A Bang! poses the question “Do all stars eventually explode?”. The Hubble Space Telescope has certainly found a star that will eventually explode. In fact, as Phil on the Bad Astronomy blog says, Hubble astronomers have caught a supernova in a galaxy right at the point it is beginning to ‘go off’.
If a star is big enough when it dies it can form a black hole. Alan Boyle, of Cosmic Log, explores how new simulations of black hole interactions are showing the disparity between Newton’s and Einstein’s gravitational theories.
With the release of the new Indiana Jones film a matter of months away, Rob carries out his own astronomy related archaeological investigation of a prehistoric site in Alabama in the USA, over at Orbiting Frog. Though as far as I can tell didn’t find any rats, sacred relics or hidden treasure!
Meanwhile Chris Lintott reports from the Royal Astronomical Society’s National Astronomy Meeting (on the NAM blog) on the discussion held in Belfast on the current funding situation of UK astronomy and particle physics.
One of the big tasks for those returning to the Moon and then looking forward to Mars is how we are going to carry out day-to-day tasks, like exercise and growing plants for food etc. Ken Murphy at Out of the Cradle explores how we might be able to grow plants in the lunar soil in part one of his post ‘Of a garden on the Moon’. Let’s hope when we get to the Moon or Mars they also have Internet access.
For those of you that can’t get enough of Mars though the Martian Chronicles team have another update on the Opportunity Mars Exploration Rover, including a stunning panorama of the martian ‘Cape Verde’ rocky outcrop. When we do get to Mars maybe we will move our bases around with giant robots, Colony Worlds investigates what that might involve. And if you are new to the excitement of martian exploration then Stuart has some tips on how to survive your first Mars landing. Meanwhile, Bill Dunford at ridingwithrobots.org has an incredible animation of Victoria crater taken at different times (and illuminations) during a martian day.
Centauri Dreams skeptically ponders whether the SETI program should search for extraterrestrial constructions known as Dyson Spheres, and asks if any other potential civilizations around other stars think like we do. Clearly when we humans want to venture out into space we are going to have to develop new technologies. Next Big Future has an article on how carbon nanotubes may be used in future space power and propulsion system whilst Henry Cate reports from Space Access 2008.
Music of the Spheres blogs about the 2008 Space Expo at the New England Air Museum. Even though the Space Shuttle simulated flights made by visitors to his stand might not have had the smoothest landings that NASA has seen, their educational value was worth it all.
A Mars Odyssey also brings us up-to-date on the launch of the Soyuz from Baikonur on the latest ISS Expedition 17.
Well that’s about it for this week’s Carnival of Space, remember that you can find a list of all previous carnivals on the Universe Today website.
Top: Artist’s impression of a GRB. Credit: NASA
Middle: Hubble has spied an exploding star in this galaxy (NGC 2397). Credit: NASA, ESA & Stephen Smartt (Queen’s University Belfast, UK)
Lower middle: Artist’s impression of a MER. Credit: NASA/JPL
Bottom: Touchdown for the Shuttle. Credit: NASA
Brilliant Noise @ Bristol’s Arnolfini gallery
Yesterday a few of us from the magazine went to see the Brilliant Noise exhibit at the Arnolfini gallery here in Bristol. The exhibit is based around a 5 month placement of two artists at NASA’s Space Sciences Laboratory at the UC Berkeley.
I won’t give away all the detail but the exhibit uses raw videos of the Sun (from various solar spacecraft) followed by some interviews, on the big scientific quandaries, with scientists from NASA.
I haven’t seen science portrayed so well, in art, for a long time — the exhibit is well worth a visit. The power of the Sun, its magnetic field and the turbulent nature of its surface and atmosphere was conveyed with incredible power and real feeling. If you are Bristol way then I definitely recommend you pop in.
The Sky At Night – The Sun revealed
Just a quick reminder that The Sky At Night is on BBC Four tomorrow night at 20:00 (more details, repeats etc., here). The title is ‘The Sun revealed’ and looks as if it will be covering the onset of solar cycle 24 and the Ulysses spacecraft which I blogged about recently.
07.04.08 edit: If you are in the UK you can also watch the programme on BBC iPlayer here for the next 6 days.
Exoplanet NAM post
I’ve written up a new post about today’s NAM announcement of the discovery of an embryonic exoplanet. The first paragraph is below:
“Astronomers here in Belfast have just announced that they have discovered what they believe to be the youngest ever planet observed. So young that it may have not completely formed yet. They used radio telescopes in the UK (the MERLIN network) and in the US (the VLA) to study the star system of HL Tau, a star in Taurus about 520 light years from Earth”
You can read the full article and see the pictures here.
NAM day two
Well today is day two of the National Astronomy Meeting. I’m going to be posting any future NAM news I have on the NAMblog so be sure to check there for the latest NAM news. Today has kicked off with some great plenary session lectures on the acceleration of the Universe and the dynamic nature of the magnetic fields on the surface of the Sun. Chris and I have posted two takes on Dr Brian Schmidt’s ‘Measuring cosmic acceleration’ talk, why not take a look.
NAM news 2: Massive starburst in the early Universe
Dr. Scott Chapman from the Institute of Astronomy in Cambridge has just presented the latest results from a collaboration between the MERLIN UK radio telescope array, Keck (at optical wavelengths), the VLA in the US and the Plateau de Bure submillimetre observatory in France. The results show that there was a group of galaxies in the early Universe that experienced an incredible burst of star formation about 2 billion years after the Big Bang. This phenomenal burst of activity was observed in galaxies that were shining a mere 3 billion years after the Big Bang and is thought to have been vastly more dramatic than any star formation we see nowadays.
Remarkably it was only until relatively recently that astronomers detected a similar gathering of sub-mm galaxies in the early Universe. These galaxies are particularly faint in optical wavelengths but very bright in the radio wavelengths. Instruments like SCUBA mounted on the James Clerk Maxwell Telescope (JCMT), on Mauna Kea in Hawaii could see the sky in sub-mm wavelengths and so could detect them; allowing astronomers to investigate their nature. Yet astronomers believed that these galaxies were only part of what was going on (star-forming wise) in the early Universe, because SCUBA was good at looking at relatively cooler sub-mm galaxies.
Now, these new results from the collaboration of many telescopes do indeed show a gathering of slightly warmer galaxies, not altogether different from those spied by SCUBA, undergoing dramatic star formation. The observations indicate that these galaxies are surrounded by vast clouds of gas. That gas, the astronomers argue, will keep the star formation going at a tremendous rate for “hundreds of millions of years”.
You can see images from the results and a very cool video here.
NAM news 1: SuperWASP strikes (10x)
One of the results that has just been released from the National Astronomy Meeting is that the SuperWASP exoplanet hunting project has discovered an incredible 10 new exoplanets. SuperWASP is an ingenious project which uses eight sensitive CCDs on eight wide field telescopes to monitor a huge number of stars in the night sky. It can record an incredible 100,000 stars in one image! What they are looking for is the tell-tale blink (more of a temporary and gradual dimming) of a star’s light which indicates a planet passing in front of the star.
This method of looking for the dimming of a star is known as the ‘transit method’ of exoplanet hunting. There have been around 270 exoplanets discovered so far and 45 of those found have been via the transit method. What’s even more impressive is that of those 45, 15 were detected by the SuperWASP instruments. The new planets that the robotic telescope has discovered range in masses of between half and just over eight Jupiter masses.
If you haven’t heard of the SuperWASP project or want to find out more then have a read of their pages here.
Above: The SuperWASP-South instrument array
Credit: SuperWASP
Touchdown at NAM
It’s great to be visiting Belfast for this year’s National Astronomy Meeting. It’s my first visit to the city and having arrived only half an hour ago I’ve already seen many old friends. More importantly it looks as if there are going to be some really interesting science results coming out of this year’s meeting. Chris has a post up on the new Hubble result which astronomers here at Queen’s University (who are hosting NAM this year) worked on. There’s an interesting lecture session on galaxy formation and evolution on in just over ten minutes so more soon…
