The European Southern Observatory operates several observatory sites in the southern hemisphere, including the world famous Paranal Observatory, home to the Very Large Telescope (the VLT). This afternoon I stumbled across an amazing video of the VLT which shows this incredible facility, high in the Atacama Desert, in a way I’ve never seen it before — it’s in 3D!
The video is the work of astrophotographer and head Optics Engineer on the VLT, Stéphane Guisard. Stéphane has recently been working with ESO and fellow astrophotographer Serge Brunier to create some truly stunning images for ESO’s GigaGalaxy Zoom project, which you can check out here. There’s lots I love about this video. From the ISS zipping over to the excited movements of the telescopes and the way it appears the observatories are living and breathing things inspecting the skies above them. Grab a pair of 3D specs and check it out for yourself below.
© Stéphane Guisard. Many thanks to Stéphane for giving me permission to post this cool video on the blog. Click the video to go to a larger YouTube version.
Video credit: Sky At Night Magazine. Click ‘HD’ for high quality version.
A few of us from Sky At Night Magazine visited the 2009 Joint European National Astronomy Meeting at the University of Hertfordshire, in late April. Whilst there we filmed two special episodes of the magazine’s vodcast, the first of which (an extended 10 minute episode) has just been released. In it we talk to Prof Michel Mayor, who tells us about a new extrasolar planet he and his colleagues recently discovered, and we chat with Prof Bruno Liebundgut from ESO about the European Extremely Large Telescope. Part 2 will be along next month with a special interview with another one of the JENAM’s wheely interesting delegates!
How the real ALMA will look. Credit: ESO/Calcada/Heyer/Zodet
ALMA is the Atacama Large Millimeter/submillimeter Array, a huge arrangement of 80 astronomical antennas currently being built by several organisations on the arid plains of the Atacama Desert, in Chile. It will observe the sky to explore in detail, amongst other things, the origins of the Universe, stars and extrasolar planets. This morning I had somewhat smaller ambitions.
Stuart mentioned on Wednesday about the instructions/plans for a model ALMA antenna that the team at the National Astronomical Observatory of Japan — who are involved in building ALMA — have on their website. So this morning I thought I’d have a go at making one. I printed the plans out and had them photocopied onto 300gsm A4 card at the local stationery store. A few hours later I had something that, remarkably for me, actually looked like the antenna in the instructions. Here are a few pictures I took during the construction process.
My attempt at making the NOAJ’s ALMA model. Credit: WillGater.com
In (1) the main dish and part of the fork arms are done; in (2) you can see the base taking shape (I substituted a small piece of dowel to support the weight of the main dish) and (3) shows the finished model. If you want the plans to build your own ALMA antenna then they are on the NOAJ website here and you can find out more about the project itself on the new ALMA website here. Now though, I’ve got to find the time to build the other 79!
NGC 2264 containing The Christmas Tree cluster. Credit: ESO
Sometimes it’s nice just to sit back and revel in the countless images that are produced by the world’s observatories, be they in space or on the ground. It might be a friend’s ‘amateur’ astroimage one day and a celestial scene from Spitzer the next. Despite the title of my previous talks, we all love a good pretty picture.
With this thought in mind then, here’s a newly released image from the European Southern Observatory of NGC 2264 — an object that contains the festively named Christmas Tree cluster. The cluster, made of young blue stars, is surrounded by an enormous star forming nebula. The startling rich ruby colour of the nebula is coming from the glowing hydrogen gas that is being excited by ultraviolet radiation, from the young (bluer) stars within the cluster. Sitting atop the ‘Christmas tree’ is the object astronomers call the Cone Nebula — a huge tower of cool gas that protrudes into the main nebula. The Cone Nebula has been observed many times before, perhaps most notably by the Hubble Space Telescope.
Scientifically, there are loads of interesting facets to this region from stellar families to signs of jets from infant stars (called Herbig-Haro objects) and even dust being gently corralled by starlight. Mainly however, this image has been released just for us to enjoy. You can read more about the NGC 2264 region (and download some very large versions of the image) from the ESO website here. For now though, let me take this opportunity to wish everyone a very safe and enjoyable holiday and a successful International Year of Astronomy in 2009!
The stars at the centre of the Milky Way, in infrared. Credit: ESO/S. Gillessen et al.
My colleagues at ESO have just published a press release I worked on about a study into the black hole at the centre of our galaxy — the Milky Way. The release is the largest one I’ve done to date, and great fun to do too — not least because of the several fascinating intertwined stories within it. I’ll start with the big one though.
That is, a 16 year long study by astronomers (from the Max-Planck-Institute for Extraterrestrial Physics in Germany) has given us the best empirical evidence, so far, of the existence of truly massive black holes. Not only does the evidence verify the existence of these leviathan objects, it also shows that one is “beyond any reasonable doubt” hiding at the heart of the Milky Way, with a mass of some four million times that of the Sun. Here’s a section from the start of the release:
“By watching the motions of 28 stars orbiting the Milky Way’s most central region with admirable patience and amazing precision, astronomers have been able to study the super-massive black hole lurking there. The new research marks the first time that the orbits of so many of these central stars have been calculated precisely and reveals information about the enigmatic formation of these stars — and about the black hole to which they are bound.”
An artist’s impression of the orbits of the central stars. Credit: ESO
Incredibly, over the course of the study, one star (known as ‘S2′) was even able to make a complete orbit of the Milky Way’s hub. Yet it gets even better. Thanks to the observations we can now watch S2 whirl around (with all its companions) in actual infrared images from ESO’s telescopes, taken over the 16 years. The telescopes use adaptive optics to counteract the problems associated with trying to observe through Earth’s turbulent atmosphere. Observing in the infrared also allows the telescopes to penetrate the thick dust and gas of the Galaxy, and thus peer straight at these intriguing central stars. You can watch the animation of these real images in a (7MB) Quicktime video here. The motion of the stars has been sped up by just over 30 million times!
A frame from the video (see link above). Credit: ESO/ R.Genzel and S. Gillessen
If you want to get the full story you can read the whole press release here. There are some great videos to go with the article so be sure to have a look at them on the ESO webpage. And of course check out the second episode of the ESOcast (summarising the result), here. It’s great to see that, already, this fascinating result has sparked the interest of some major news outlets including here, here and here.
Omega Centauri as seen by the WFI. Credit: ESO/EIS
I’ve just had a new press release published over at the European Southern Observatory’s website. It’s about an image (above) of the stunning globular cluster Omega Centauri, taken with the observatory’s Wide Field Imager camera. Here’s a snippet from the release:
This new image is based on data collected with the Wide Field Imager (WFI), mounted on the 2.2-metre diameter Max-Planck/ESO telescope, located at ESO’s La Silla observatory, high up in the arid mountains of the southern Atacama Desert in Chile. Omega Centauri is about 150 light-years across and is the most massive of all the Milky Way’s globular clusters. It is thought to contain some ten million stars!
Omega Centauri is roughly 12 billion years old and had long been thought to be just a massive globular cluster – a huge, roughly spherical, collection of ancient stars. But recent research has found that there are several generations of stars in Omega Centauri – not a typical trait of globular clusters. This discovery has led to some astronomers suggesting that the cluster is actually the remnant centre of a dwarf galaxy. You can read the full story here. And be sure to have a look at the high resolution image, to get a real sense of perspective, with the millions of stars in the cluster. I’ve included a small crop below.
A crop of the left hand side of the new WFI image. Credit: ESO/EIS
Looking at this stunning new picture* from the European Observatory (below) you’d be forgiven for thinking that this is a region of calm beauty, hanging in interstellar space. This is the object known as Gum 29 – a huge nebulous region of ionised hydrogen gas sitting around 26,000 light-years from Earth just on the outer part of the Carina spiral arm of our galaxy, the Milky Way. Whilst the swirling clouds of gas do look serene, they are detracting from a maelstrom of violence which is being perpetrated by two massive stars within the cluster, at the heart of the nebula. The cluster is known as Westerlund 2 and it is the location of a binary star system (known as WR20a) composed of two huge stars with masses of 82 and 83 solar masses.
Gum 29 hides a secret. Credit: ESO
These stars are on the verge of dying and are classified by astronomers as ‘Wolf-Rayet’ stars. These are stars that are ejecting huge quantities of material (like gas and dust) as they go about the last stages of their lives. As they eject this material it is lofted on strong stellar winds which rush away from the stars at incredible rates, sometimes as quickly as several thousand kilometres every second. The binary star system of WR20a is circling every 3.7 days and as it does the stars’ respective winds buffet each other.
The result is a violent collision of gas which prodcues a flood of X-rays, that can be seen by X-ray observatories like the Chandra Observatory orbiting Earth. This blast of X-rays can be seen in the X-ray image here (from Chandra) as a yellow fuzzy blob, towards the bottom right of the cluster. You can also see the (visible) light, from the system, in the image below. In time the stars of the WR20a system will die, as their cores collapse, most likely creating a blast known as a supernova. That’s going to be an incredible sight when it happens and we’ll have a front row seat, if we’re still around.
The binary system WR20a. Credit: ESO
Astronomers are interested in studying these incredible objects as they can then get a better understanding of what happens to massive stars at the end of their lives and refine their models of stellar evolution. It’s thought that most extremely massive stars in the Universe will behave like WR20a and become Wolf-Rayet stars prior to exploding as supernovae. But there are still some stars which throw the proverbial spanner in the works. Take Eta Carinae for example (below). It’s an odd, extremely massive, rare type of star known as a luminous blue variable. It’s been expelling huge amounts of material for a long time and is four million times more luminous than our own, rather meagre in comparison, Sun. Today we see the star surrounded by two huge lobes of pinkish gas, each formed during one of the star’s larger ejections, seen to appear in the early 1840s. Some astronomers think that Eta Carinae is exhibiting Wolf-Rayet star like properties due to this extreme behaviour, and may even be on its way to becoming one. But astronomers from the Gemini Observatory have recently found that the material moving out from Eta Carinae is travelling much faster than if it was being swept on fierce stellar winds.
Eta Carinae. Credit: Jon Morse and NASA/ESA
They have found that the gas and dust flying away from the star is moving away (at speeds up to 6,000 km/s) with a little less energy than you might expect from the blast of a supernova. Below you can see a wonderful animation depicting the scenario, with a blast wave emerging from the star. That blast wave excites the gas from previous ejections and we begin to see the familiar shape of the two lobes around Eta Carinae, that we see today. But the star hasn’t gone supernova, so what’s going on? Well astronomers don’t quite know at the moment and so it seems Eta Carinae has become just that little bit more interesting and peculiar. Some argue that perhaps Eta Carinae is similar to other stars which appear to have released an explosive amount of energy at the end of their lives, yet haven’t gone supernova. However, as yet, there’s no concrete theory on how these stars might evolve (at the end of their lives) and what may trigger their violent ejections. Maybe we are looking at a new type of stellar explosion? Even so, if we aren’t sure what’s happening with Eta Carinae, will we actually have enough time to study it to find out? Well the answer is yes, it looks as if we’ll have a little while yet. Astronomers from ESO think that it might be 10,000 years from kicking the bucket. That’s still very soon in the lifetime of a star mind you. Nevertheless, it appears that Eta Carinae is going to be intriguing, at least several, generations of astronomers for millenia to come.
- Eta Carinae’s expanding shells. Credit: Gemini Observatory, artwork by Lynette Cook.
*I recently finished writing the press release for the Gum 29 image and you if you’re interested you can read it in full on the ESO website here.
Last week ESO, the European Southern Observatory, released a press release about their observations of the gamma-ray burst GRB 080319B – one the brightest gamma-ray bursts ever seen – that occurred in March of this year. The press release covers the results of a new investigation into the burst. Astronomers who studied the burst have come to a startling conclusion about its orientation! From the press release:
“We conclude that the burst’s extraordinary brightness arose from a jet that shot material almost directly towards Earth at almost the speed of light,” says Guido Chincarini, a member of the team.
Above: Artist’s impression of GRB 080319B. Credit ESO
I was asked by the press team at the ESO headquarters, in Germany, to write the background story of that burst, including the many different observations made by telescopes around the world and how and when it appeared. The finished article has now been posted alongside the release as a two page pdf. You can read the ESO press release here and also download my feature story on GRB 080319B here (pdf download in link).
The stunning galaxy M83. Credit: ESO
My first press release for the European Southern Observatory has now been released. It accompanies what is, of course, the real interest in the story – a fantastic new image from the observatory’s Wild Field Imager camera. It shows the stunning spiral galaxy M83, arguably one of the most beautiful galaxies in Messier’s famous catalogue of deep sky objects. Here’s a snippet from the press release:
This dramatic image of the galaxy Messier 83 was captured by the Wide Field Imager at ESO’s La Silla Observatory, located high in the dry desert mountains of the Chilean Atacama Desert. Messier 83 lies roughly 15 million light-years away towards the huge southern constellation of Hydra (the sea serpent). It stretches over 40 000 light-years, making it roughly 2.5 times smaller than our own Milky Way. However, in some respects, Messier 83 is quite similar to our own galaxy. Both the Milky Way and Messier 83 possess a bar across their galactic nucleus, the dense spherical conglomeration of stars seen at the centre of the galaxies.
You can read the full press release and download a hugggeeee version of the image here.
The European Southern Observatory is running an international competition for students (in primary or secondary education) called ‘Catch a Star’. Entrants can either submit reports or artwork on an astronomical topic of their choice.
The deadline is Friday 29th February 2008. Prizes include T-shirts, DVDs, posters as well as (for the top prizes) trips to various worldwide observatories including ESO’s Paranal site in Chile!
For more information and the full rules, details and requirements visit the ESO ‘Catch A Star’ site here.