Image of the Week 30/07/10: Star birth gone wild
At Galaxy Zoo, several of us have been lucky enough to get this soft-looking beauty to classify:
The Sloan Digital Sky Survey's view of ARP 220
From the SDSS telescope in New Mexico, which supplied the images for Galaxy Zoo’s first two projects. You can look up more details from the SDSS pages here.
From the funny shape, especially the loops towards the right, we can see that it’s a past merger – a collision of two galaxies many millions of years ago. While it’s unlikely that any stars or planets crashed into each other (they are just too far apart), the immense gravity drags both structures around like an adventurous octopus playing with ribbons.
We can also see that it’s got a huge dust lane in the middle. Dust is usually larger particles than the hydrogen and helium gas which is abundant in the Universe, and from which stars form – it’s much rarer, but if it lies over a large enough area it blocks light (this is why we can’t see the centre of our own Galaxy).
The name ARP 220 comes from the Atlas of Peculiar Galaxies, compiled by Halton Arp. ARP 220 is in the constellation Serpens, and 250 million light years away.
It’s been an object of interest before. Back in 1997, it was Astronomy Picture of the Day.
And it’s continued to be interesting. Yesterday, Chris Lintott sent a tweet about a conference he’s attending – an entire talk was given to this object. I did not know until that moment that ARP 220 is the most luminous object in the local Universe.
Here is Hubble’s view:
Hubble has just had a bit of a field day imaging this monster with its Advanced Camera for Surveys, which revealed a cosmic sort of “baby boom”. This often happens with mergers: gas clouds, formerly minding their own business and cheerfully orbiting the centre of their Galaxy with everything else, suddenly get slammed into other gas clouds from the intruding galaxy, collapse, and set off a firework display of new star birth.
In ARP 220, it’s happening as never before. Over a 5,000 light year area – which is pretty titchy for space, only 5% of the Milky Way – there is as much gas as the Milky Way contains.
The clusters of star birth are so close together that they look like individual stars. There are two main groups which have been surveyed: one is only 10 million years old, the other about 70 million. The younger group contains larger stars. It is not yet known whether there were two “baby booms” or whether ARP 220 is undergoing a continuous starforming phase.
The dust blocks the view, but glows brilliantly in infra-red light. Its X-ray output has also captured the attention of astronomers – the intense activity has created a “superwind” that Chandra has picked up, and its effects can be seen 75,000 light years away.
The further out lobes are probably remnants of the merger. These filaments of gas are still hot – glowing, but unlikely to form new stars for a long time.
Astronomers say the conditions in ARP 220 may mimic an earlier, smaller Universe in which galaxy collisions and outrageous star formation were a lot more common.
One final version of this picture comes not from the past but from the Futurity science blog – the Saburu telescope obtained a false-colour image of the merger’s far-flung tidal debris.
If that’s not enough pretty pictures for you, Google Images yields a healthy crop. French speakers should particularly enjoy this one!
The Apollo Program
Here at YA we really love astronomy, but we also really like spaceflight. for the next couple of months I’ll be posting (hopefully) once a week about the missions of one of my favorite human spaceflight programs. It is (as you might have already guessed from the title) the Apollo Program.
Apollo Program Patch
On each post, I plan on writing an overview of the mission, the crew, the objectives, what they did, some fun facts, and maybe something else, we’ll see…
I guess I’ll start next week, and it will be going on for a while. I’m really looking forward to it. I hope you are too!
Scientists dig deeper in the search for dark matter
The search for dark matter is hard. Not only is it dark which makes it hard to visibly see, and no shining a torch on it wont help 
, but also the rare dark matter events that are sought by the cryogenic dark matter search II (CDMSII) could be being masked by cosmic rays striking the earth.
Part of the SNOLAB facility in Canada Credit: BBC
Originally the CDMSII was situated in a tunnel below the Stanford university campus, most probably run by a load of students who never saw the light of day, however it has moved on a long way from those humble beginnings and at the moment the CDMSII is situated in the Soudan mine in Minnesota on the 27th level which is about 2341 ft below the surface, but Dr Marek Kos who is a team member for the experiment outlined details at the high energy physics conference in Paris that the CDMSII could be relocated from Minnesota to the SNOLAB facility in Ontario, Canada, which is about 2 km under ground and this should hopefully stop any interference from those pesky cosmic rays.
Last year in 2009 team members hit the headlines when they reported to have discovered two signals in their detectors that could have been caused by dark matter, however they did report that the chance of these being caused by WIMPS (weakly interacting massive particles) was low. The CDMSII detects these WIMPS at extremely low temperatures and watches out for the release of energy when a particle hits an atom in germanium and silicon crystals within the detectors, it is believed that when a WIMP hits a particle it interacts with the nucleus of the atom and this is known as a nuclear recoil, however the detectors also pick up electron recoils which are interactions between the electrons of an atom and some of these can look allot like nuclear recoils. Hopefully because of the success of last year the CDMSII will be getting better detectors which will be better at distinguishing between nuclear recoils and electron recoils and eventually the team members are hoping that there plans to move deeper underground to the SNOLAB facility will go ahead and that they will be getting ever closer to finally finding that elusive dark matter.
China Maxes Out on Rocket Power
As China continues to emerge as one of the worlds superpowers and reach for the stars, it’s only natural that they reach out and develop new rockets. The current rocket in development is Long March 5. A prototype should be ready by 2012 with test flights the following year. The rocket will be ready to carry humans, modules and satellites to LEO and to geostationary orbit.
Li Tongyu who is the general manager of the marketing department at the China Academy of Launch vehicle Technology (CALT), says that engineers there are currently studying a rocket engine that is capable of generating 600 pounds of thrust. Long March 5 will only produce 120 pounds of thrust.
Li Tongyu says that rockets capable of 600 pounds of thrust are justifiable only for carrying humans to the moon.
It was also mentioned earlier in March that the next Chinese heavy launch vehicle could produce 300 pounds of thrust. This would look like Long March 5 but on a bigger scale, with one main thruster in the middle and four straps on boosters.
No one knows for sure where we will end up and weather we will explore as separate nations or as a planet. And that is what the Young Astros was set up for – to unite the next generation of space scientists throughout the world and to teach everyone to work and live in peace.
James Webb Space Telescope: Hubble’s Successor
James Webb is a infrared space telescope currently under design and construction. The telescope launch is expected to take place some time during or after 2014. It is a part of the next generation of telescopes that will take the place of famous Hubble Space Telescope. The Webb Telescope is a joint project between NASA, the European Space Agency and the Canadian Space Agency.
Full-scale model of James Webb Space Telescope (credit: Nasa)
This new telescope will study the full history of our universe: since the Big Bang until the formation of Solar System. It have four main objectives: study the first bright objects in the universe; find out how exactly the galaxies were formed; discover more about the birth and development of stars and planets; and study the physical and chemical properties of solar systems (including our own) with the hopes of finding the origins of life.
There are some similarities between Hubble and Webb – both are (or will be) are designed to improve our knowledge about stars and galaxies – but there is a big difference between the two: Webb will explore the universe mainly in the infra-red frequency range, while Hubble ‘sees’ the optical (visible) and ultra-violet range.
Webb take around 3 months after launch to take up its position in orbit and begin observations. It will orbit around 1.5 million kilometres from Earth.
With this new tool, astronomers hope to shed light on some of the questions about the universe the answers to which currently remain illusive.
You can read more about Webb here.
Bucky Balls in Space
Astronomers have discovered a specific variety of carbon called Buckminsterfullerene or Bucky Balls.
An Artist's concept of the Bucky Balls Credit NASA/JPL-Caltech
This is a molecule of carbon containing 60 carbon atoms covalently bonded together in hexagons and pentagons to form football like structures.
There where first shown to exist in a laboratory experiment twenty-five years ago.
They have been detected on Earth in the soot given off by candle flames and in meteorites and within certain layers of rocks in the Earth’s crust.
Despite their existence having been proven to occur outside laboratory conditions this is the first time they have been definitively detected inside deep space.
The molecules have been detected by NASA’s Spritzer infra-red telescope in the planetary nebula Tc-1. The molecules have been detected along with a close chemical relative – C70 which has a slightly elongated structure.
The molecules are the largest free molecules yet identified in open space. Tc-1 is located around 6500 light years away from Earth in the direction of the Southern constellation Ara.
Despite being astrochemically ‘large’ and slightly more than three times the size of water molecules the Bucky Balls are only 1 nanometer in size or in more understandable terms – 1 billionth of a meter – 10,000 times thinner than a human hair.
Due to their size and chemical properties, Bucky Balls are playing a key role in the development of nanotechnology – technology that works at the nanometer level – and have been proposed to play a role in new armor and electrically superconducting technologies. Their discovery in space marks a giant step forward in the detection of specific forms – or allotropes – of elements at the vast interstellar scales of the universe.
Bucky Balls have potentially been detected twice before; one of these detections had contaminants from other chemical sources and the second has yet to receive confirmation so this is the first definitive time the molecules have been detected away from Earth and marks a significant achievement for astrochemistry.
Image of the Week 23/07/10 – Catching a Cluster of Stars
This week’s image is another Cassini image. This time of the globular cluster Omega Centauri or NGC 5139.
Catching a Cluster of Stars Credit: NASA/JPL/SSI
The image was captured by the spacecraft’s narrow-angle camera on March 29 2009 when the space craft was orbiting 1.2 million kilometres from Saturn itself.
The craft was photographing the planet’s F ring when the cluster happened to pass through the camera’s field of view. NASA has compiled the 13 images containing the cluster into a short video sequence visible here.
Omega Centauri is thought to be the remnant of a former satellite galaxy that merged with the Milky Way early in our galaxy’s life. The majority of the galaxy is believed to have been torn apart with only the dense gravitationally bound core remaining intact orbiting the Milky Way itself. This core is believed to contain several million stars with the core being so dense that a star may only be 1/10 of a light year from its nearest neighbour. In comparison in Sol whose nearest neighbour is Proxima Centauri located 4.2 light years away.
Omega Centauri is located around 15800 light years from Earth and is the only globular cluster visible with the naked eye and can be observed in the constellation Centaurus.
Revolutionary Astronomical Words
Hello everyone, and thanks to the Young Astronomers for allowing me aboard despite being a comparatively crumbly non professional astronomer! Now, assuming I can get WordPress to bend to my will, my first post is going to be about words in astronomy that end up not meaning quite what they should, if they don’t want to be misleading. Like all sciences, astronomy is done pretty much in the dark (sorry about that) – and sometimes names stick before we know what we’re actually talking about. Here are a few.
Revolution
When we hear of revolts and revolutions, we think of noisy coup d’etats in which the angry mob displaces the, er, other angry mob – and either things improve for the country in question or they don’t, but in any case, it’s a radical change. But the word “revolution” actually means “going round in a circle”. The Earth completes one revolution round the Sun every – you got it – year. Doesn’t seem a very revolutionary word, does it?
It came from Copernicus. His revolution was, really, the ultimate revolution in Science: the recognition that we are not at the centre of the Universe; that, rather, we revolve around the Sun. The book he wrote (which was only published just before he died, as he knew it wouldn’t be popular!) was called “De revolutionibus orbium coelestium”, or “On the revolutions of the heavenly spheres”. It was a revolution, because it called into question the dogma of the day that the entire Universe was created for us.
Handmade oil painting reproduction of The Copernican System by Andreas Cellarius, devised by Nicolaus Copernicus.
(Picture credit: this online art gallery!)
Which, incidentally, led on to . . .
Planets
The word “planet” comes from Greek, and means “wandering star”. Apart from the odd motions planets made in comparison to the rest of the stars in the sky – which they did because they, like the Earth, were orbiting the Sun – there was no way of knowing in those days that they were any different from stars. Both looked like points of light. But stars are millions of times more massive than planets, and they give off light for entirely different reasons. To be fair on the ancient world, they couldn’t planet to happen . . .
Planetary Nebula
This is the name for beautiful nebulae such as the Cat’s Eye Nebula. They are actually nothing to do with planets, but were named as such in the 18th century when telescopes were not poweful enough to tell the difference.
The Cat's Eye nebula, a "planetary nebula" from a star too small to explode as a supernova.
(Picture credit: NASA.)
A planetary nebula is a much more gentle and orderly shell of gas than a supernova remnant. It is created when a small or medium star, like our own Sun, puffs off its outer layers at the end of its life. It’s often very hot, ionised gas, and is therefore an emission nebula – shining with its own light. It also contains elements such as carbon and oxygen, which are essential for forming rocks, planets, and life.
The word “nebulae”, however, does at least mean clouds. Astronomers referred to “spiral nebulae” many years ago, believing these to be beautiful spiral-shaped clouds at the same sort of distances as the stars in our Galaxy. They had no idea that these were galaxies millions of light years away from our own!
Astrology/Astronomy
Once upon a time, these two words meant the same thing. In the days when it was essential to know when to expect floods or plant your crops, and indeed when there were no TVs or streetlights at night, people would have known the sky very well. It would make perfect sense to think, “When such-and-such a constellation rises above that hill, it’s time to plant this out”, or “Oh dear, that one. The weather will be bad soon.” Into the Middle Ages, royals employed professional astrologers. A British tabloid newspaper claimed that Dr Brian May, the Queen guitarist who is also an astronomer, has a PhD in astrology . . .
Any word ending in “-ology” (biology, geology etc) usually means science. However, as the science and the myths separated, they needed two different names. They now have pretty well nothing to do with each other – but a lot of people don’t believe me when I say that!
Nova
The word “nova” implies newness. However, a nova is a star so old that it’s no longer strictly a star. It’s a massive explosion caused by the accretion of gas onto a white dwarf. This white dwarf is pinching this gas from a nearby star, usually in a binary system; every so often, it acquires enough for fusion to start again. It has to reach about 20 million Kelvin to do this, as a white dwarf is made of extremely compressed material which contains no hydrogen fuel to fuse (otherwise it would still be a star!). In order to make this even simpler, novae are not to be confused with supernovae, although a Type I supernova can result from the same sort of process.
The Big Bang
Time and again I’ve been told almost angrily: “It doesn’t make sense. The Big Bang was an explosion, so how could it create such an ordered Universe?”
The term “Big Bang” was actually coined as a derogatory joke, by Fred Hoyle, who preferred the steady state theory (that the Universe remains the same size and had no beginning). He said in the 1960′s on a radio program something along the lines of that he didn’t believe the Universe could have begun in one big bang. The name stuck!
We will never know what sort of noise it made – of course, even if we’d been around to hear it, it would have been so incredibly hot and violent that we’d have been smashed to bits. Certainly everything would have been bumping into each other a lot. There were no atoms and molecules as we know them, let alone solid objects or stars – everything was a seething plasma of atomic nuclei, electrons, and most of all radiation. It’s particles bumping into each other that make noise. But when the Big Bang occurred, any noise that occurred would have been inside it.
That’s because any explosion we think of today is nothing like the Big Bang at all. An explosion happens in one place, and its shock waves – flying shrapnel, for instance – fly out and damage their surroundings. The Big Bang didn’t have any surroundings. It’s easy to think of it as an expanding globe, with a centre and an edge. We think of the edge as rippling through something – perhaps the Earth! – at some point in time.
It sounds like it took place – in, well, a place. Somewhere we could go and visit. From there we’d see the evidence of destruction, perhaps everything rushing away . . .
That is everywhere and nowhere. The Big Bang happened right where you’re sitting. It happened across the room for you, and it happened on the other side of the Universe. It’s quite a mind-blowing thought. But it really wasn’t much like a bomb!
An artist's impression of the size of the Universe at the time of the Big Bang, then inflation, then its expansion.
(Picture credit: good old Wiki.)
It was really quite complex too, with inflation, and a period of darkness (because all the atomic nuclei and electrons were flying around in too disorderly a manner to let light through. This is what happens inside a cloud – there’s too much stuff in the way, so light bounces off everything in random directions and goes any old where. It also means it’s relatively dark).
And guess what else? It wasn’t big at all. It was small. It was absolutely tiny – smaller than the head of a needle – perhaps smaller than an atom! How did all this stuff in the Universe today come out of something so small? We don’t know. In fact, theoretically, such an object shouldn’t exist. It’s called a “singularity”, and it means, because it’s too small even to have a size, it must have infinite density. But we know there are black holes which are also singularities – and, really, when we look at the earlier Universe and see how much smaller and hotter it was, and when we do the mathematics, it’s the only conclusion we can come up with.
It’s not only how we began, but it’s an immense – and immensely complicated – puzzle. It’s odd to think that something so huge and important could have such a jokey, normal name. But Universes happen before words do!
Alice
Project Nebula – Novae Debris
A binary system that contains a main sequence star, like Sol, and a White Dwarf can create a cataclysmic x-ray binary. Matter from the main sequence star can be transferred to the white dwarf companion. This matter builds on the surface of the White Dwarf until it passes a critical level and a burst of fusion in the White Dwarf’s outer layer. The fusion is similar to what occurs in the cores of main sequence stars, i.e. isotopes of hydrogen being fused to create helium. Unlike in main sequence stars however this fusion occurs in the outermost layer of the White Dwarf and can only be maintained for a short time as the supply of hydrogen is quickly depleted. This burst of thermonuclear fusion creates a massive outflow of energy this allows the outer layers to overcome the star’s significant gravity and blast into space, this event is known as a Nova after the ancient Greek for new as they were believed to be the births of new stars. Despite this upheaval both the stars survive the explosion and over a period of time the system returns to its normal configuration with more matter being sucked onto the White Dwarf. The outer layers blown off in the Nova form a shell around the binary system. This can be classed as a type of nebulosity.
The nebula contains mostly hydrogen and helium. An example of such of an event is Nova Cygni 1992. As its name suggests it was located in 1992 within the constellation Cygnus – The Swan.
Nova Cygni 1992 Credit: NASA; ESA; HST;* F. Paresce, R. Jedrzejewski STScI
This time lapsed image shows the event shortly after the initial outburst (left ) with the second image (right) taken 13 months after the event. The image shows the expansion on the debris as time passes. It is however important to note that the camera had been repaired and improved between the two images.
The initial explosive force from the nova can propel the debris many thousands of kilometres across at speeds of many hundred of kilometres per second. Whilst not as powerful as the more well known supernovae, the cycle of matter build up and thermonuclear reaction can occur many times and can occur in very regular cycles making them very interesting objects to study.
Welcome to our New Editor: Alice Sheppard
Alice Sheppard
We have recruited a new editor! Meet Alice Sheppard, she lives in the United Kingdom with her family and two Cats. She has had an interest in astronomy from a young age, and is a forum moderator for Galaxy Zoo and She is an Astronomer. As well as moderating, she also has her own blog, Alice in Galaxyland. From there she writes about astronomy, people, the skeptic movement and politics, and when she does she conveys her enthusiasm to the reader in an infectious manner. When she can she writes for other websites, blogs, magazines and has recently co-founded Skeptics in the Pub in Wales.
Tell us about yourself.
At the moment I hire out wheelchairs and build up a website to make a living, but I want to be a science journalist and book writer.
I have recently co-founded Cardiff Skeptics. Skepticism is not cynicism. It means always looking at the best evidence rather than people’s opinions when extraordinary stories or claims are made.
My special favourite astronomy topics are star birth and death, astrochemistry, galaxies, and the physics of the Universe (dark matter, etc).
What started you off with astronomy?
When I was a kid I was lucky enough that there was a basic astronomy book in the house that was one of the first things I read. Then my mum and a friend got me a few more, including the Uncle Albert series, and Heather Couper & Nigel Henbest’s Space Atlas (1992!).
When I was 24, just graduated, and bored and disappointed with environmental science, I decided to be a chemistry teacher – that got me interested in physics again. I bought BANG!, and got into e-mailing Chris Lintott. He actually answered me and taught me more than anyone else ever had, and also it got much easier to look things up because he pointed me to things I ought to!
What got you into science communication?
Well at university I realised I was far better at writing than at science. I nearly did a unit called “science communication in a public forum”, but then it turned out I’d have to buy my own video player and camera so I dropped out. And then I realised I loved teaching. (Actually at school people would say “oh Alice I wrote down everything you’ve been saying all year for my exams and I got an A!”). So I’ve always loved explaining things. Galaxy Zoo really got me started though, of course. The zookeepers gave me lots of encouragement to give lectures and write articles.
What do you do at Galaxy Zoo?
I moderate, organise the OOTD (Object of the Day) rota and most meet-ups, I act as the link between the zookeepers and the Zooites when messages need to get across from one to another, and I’m also usually the one to find people to be interviewed by journalists.
Tell us about your blog
It started off as meaning to be about astronomy, to practice for being a science journalist, but I soon found out I wanted to write about people and education and politics too. Then along came the skeptics, so I started also writing about that. What I’m rather enjoying is how similar Skeptics in the Pub is to Galaxy Zoo, in the sense of groups of people who dissect science together online, and meet up and have great fun at pubs etc. Both are ordinary people on a mission. I love writing about both, and feel it’s something anyone should be able to get involved in. In both cases you need the tools and skills to get involved, and that’s something I want to bring to anyone interested, not just those already privileged to know a lot about it.
You’re a freelance journalist, what do you write about for various magazines?
I wish I more of a freelance journalist. I’ve written two articles so far, both about the zoo, though I hope to write more! One for Young Stargazers (part of the Society for Popular Astronomy magazine) and one for Astronomy Now. I’ve also guest blogged for Pulse-Project and Chris Lintott’s Universe.
Why did you want to take part in YA?
You can find Alice’s blog here, and her twitter here.
