Our own paper covering the discovery of Hanny’s Voorwerp is still working it’s way through the refereeing process. We’ve come up against a referee who really understands the subject and it’s taking time to put right our numerous missteps and to make everything clear. A new version will be submitted in the next couple of days, so hopefully you’ll be able to read it soon.

In the meantime, a group of Dutch radio astronomers have published a paper reporting their own results which is accepted and available online. They were kind enough to discuss it with us, and add some of the team to the list of authors – and they’ll be blogging here next week to tell you about what they’ve done.

It still hurts to be beaten to publication, but at least they’re friendly and it’s another sign of how this remarkable object has captured people’s attention.

In our latest (behind-the-scenes) update of the Galaxy Zoo blog software, we’ve installed a plug in that makes it easy for you to share any story on the blog that you particularly like via portals such as digg.com and facebook. If you do like a post and want to spread the word about it, all you have to do is click on`Bookmark it’ to submit the story.

A while ago we asked you to fill out a short survey about your thoughts about Galaxy Zoo. The purpose of this survey was to get an idea of what was inspiring people to participate in Galaxy Zoo. Thank you for participating in that survey. We are starting to analyze the results of that survey, and we’re learning some interesting things. We’re waiting to share the results until we are finished with all the research, so that we don’t run the risk of biasing your answers because you have heard about the results. But don’t worry, we’ll describe all the results here on the blog, just as we are doing with all the Galaxy Zoo research results.

We’d like to ask you a few follow-up questions about why you participate in Galaxy Zoo. Please click on the link below to answer a short 4-question survey. Your responses will help us learn more about why so many people have found Galaxy Zoo engaging, and will help us design future projects to be even more appealing.

Please click on the link below and fill out the short survey. Thank you for your help!

Galaxy Zoo user follow-up survey

Clear skies,
Jordan

Cape Canaveral, Florida – The space shuttle Atlantis lifted off today after a nearly flawless countdown, beginning an 11-day mission to refurbish and repair the Hubble Space Telescope for the final time. That’s how a news story would report it. But there’s a lot missing there, even from the viewpoint of spectators watching the launch. Read More…

Galaxy Zoo participants usually have a keen interest in the Hubble Space Telescope. Not only has it delivered unparalleled views of galaxies, and advanced our understanding of cosmic distances, the relation between galaxies and black holes, and their coupled evolution – but we have a project scheduled for the coming year to observe Hanny’s Voorwerp with three of its instruments. Of these three, one is currently sitting in the payload bay of the space shuttle Atlantis, and the other two are out of commission awaiting a service call by the crew of Atlantis. These views (taken from the coast about 10 km from the site) show the shuttle at dusk on May 10, about 16 hours before scheduled launch (May 11, 1401 local EDT time or 1801 UT). The rotating service structure has been pulled around to keep it clear of the launch blast, and floodlights illuminate the entire pad area for continuing work. The safety measures enacted following the loss of Columbia and its crew have led to the unprecedented situation of the shuttle Endeavour sitting on the other launch pad, ready to be prepared for a rescue mission at short notice. This is needed because, unlike missions to the International Space Station, Hubble missions do not offer a safe haven in case of damage to the thermal protection system, or from impacts with space debris. This is the final scheduled visit to Hubble, so the crew has a full schedule of replacements and repairs. Stand by for updates…

The Object of the Day thread on the forums is always worth watching, but today’s is particularly good. Jules explains what the mysterious object that forms the ‘O’ in the Galaxy Zoo logo is – and if you don’t know already, you might be surprised to find it isn’t a galaxy…

Earlier this month Galaxy Zoo took part in the 100 Hours of Astronomy, which was extremely successful and enjoyable too! Since then, several zooites have remarked that it was great fun and a real inspiration to classify more. So just for today, we decided we’d like to have another go.

Galaxy Zoo was inspired by zookeeperKevin’s PhD thesis a few years ago. Trying to find those blue ellipticals, he was running a program separating spiral from elliptical. He classified 50,000 galaxies in one week. ZookeeperChris was later heard to say in a lecture: “A PhD student will classify 50,000 galaxies before telling you exactly what you can do with the other 850,000.” (The rest is history.) Among other units, this incredible achievement was given a name, “The Kevin-Week”.

Today is Kevin’s 28th birthday. To celebrate, Arfon has set us up a Zoonometer again for today. We have a very special target: How many Kevin-weeks can we collectively click our way to on Kevin’s birthday? Let’s find out.

Thank you all for your inspiration, and Arfon for his kindness and technical genius – and happy birthday Kevin!

Today’s guest blogger is Shanil Virani, a grad student at Yale who has been working on the X-ray follow-up of IC2497 & Hanny’s Voorwerp:

Most of you, if not all, are familiar with the story of Hanny’s Voorwerp — an unusual object found by the GZ team near the disk galaxy IC 2497. The optical spectrum of the object (taking the light and splitting it up into its “rainbow” of colors) suggests it was “lit up” by an active galactic nucleus in the nearby galaxy IC 2497. Active galactic nuclei, or AGN, are believed to be powered by supermassive black holes that reside in the centers of galaxies devouring the gas and dust that come within their reach. Every galaxy has one, including our own Galaxy! But how do you find something you can’t see? The best evidence for the existence of supermassive black holes actually comes from near-infrared observations of the orbits of stars right near the central black hole in our own Galaxy (see this short animated movie if you have never seen it before!). Simple application of Newtonian mechanics demonstrates that these stars orbit a central object whose mass is approximately 4 million times that of the Sun and is confined to a region roughly the size of our Solar System! The only physical object we know of with such properties is a supermassive black hole. However, with the launch of a new generation of X-ray observatories we now know that observations at X-ray wavelengths also provide definitive evidence of whether an object is a black hole as X-ray observations probe the extreme physical conditions in the immediate vicinity of a black hole. Recently, we have been awarded significant observing time with two space-based X-ray observatories — the primarily European XMM-Newton telescope and the Japanese/American Suzaku Observatory — to determine whether IC 2497 hosts an active supermassive black hole that can explain the mystery of what’s lighting up Hanny’s Voorwerp.

Since my Ph.D. dissertation involves X-ray astronomy, principally carrying out one of the deepest surveys of the X-ray sky performed to date (see my web site), Kevin and I thought it would be cool to blog about what X-ray astronomy is and how we do it since it is completely different than optical astronomy. In a second blog post later this summer, I will provide a more physical picture of what we think is going on in IC 2497 and how we are testing this hypothesis with data from these X-ray observations.

This year we are celebrating the International Year of Astronomy which in part commemorates the 400th anniversary of Galileo’s first astronomical use of the telescope. From 1609 to the present, we’ve seen a remarkable revolution in technology in optical astronomy that has allowed us to see deeper into the cosmos. X-ray astronomy, on the other hand, is a relative newcomer having only begun in the 1950s. X-ray photons are energetic enough to go through objects compared to optical photons but they are also easily absorbed. Only a few millimeters of bone or a few meters of air will stop them. The latter is critical for life to occur on the surface but it also means we need to get above the atmosphere if we wish to do X-ray astronomy. The former tendency, for X-ray photons to be absorbed, is what is exploited when we go to the doctor’s office and get an X-ray of our teeth or bones. In this case, a film is placed behind the object we are interested in (teeth in the case of a dentist) and X-rays are then shone on the patient. The teeth and bones easily absorb these X-rays while the tissue does not. The dentist then uses this image to identify cavities, etc. In the case of X-ray astronomy, however, we collect X-ray photons from celestial objects rather than exposing objects to human-made X-rays and taking a picture (like in the dentist example). This also means that the way in which X-rays are collected are fundamentally different than optical telescopes. In optical astronomy, we all have this picture in our mind of a large telescope tube at the back of which sits a large mirror to collect the light which is then focused onto an instrument. This prescription does not work in the X-rays because they are too energetic to be collected in this way — they would just be absorbed by the mirror. Instead, X-ray photons are softly deflected several times so that they can be focused directly onto the instrument. Think of skipping pebbles off the surface of the water at a beach. The image below (courtesy of the Chandra X-ray Observatory’s education web site) provides a good schematic of how modern X-ray satellites work. The more mirrors you have nestled together, the more collecting area you have, and therefore the more fainter you can go.

The data that come back from these observatories are also different then the kind of data that you are used to seeing from optical telescopes. For example, we are all amazed by the beautiful images produced the Hubble Space Telescope. It has produced some of the prettiest pictures such that even rock bands have used its images for album covers (see Pearl Jam’s Binaural for a great example!). This is the basic product, an image, that the HST produces and its observers analyze. Now, they also have more advanced facilities so that you can take a spectrum of a source but you generally can’t do both simultaneously. With X-ray instruments, you get imaging and spectroscopic data and timing data all in one go if your source is bright enough or if you stare at it long enough! It is exactly these attributes we intend to exploit in the data returned by our Suzaku and XMM-Newton observations of Hanny’s Voorwerp to determine if IC 2497 does indeed host a supermassive black hole! The imaging, spectroscopic and perhaps even the timing data will allow us to conclusively demonstrate if the black hole in IC 2497 is currently active enough to explain Hanny’s Voorwerp. If it is not, then that may even be more interesting as it would be providing us with a rough diary of what are the eating habits of the supermassive black hole! Either way, a great story is about to unfold and will reveal another level of detail about this exciting object.

Stay tuned for more details as the data begin to come in and are analyzed. In the mean time, if you are interested in learning more about the history of X-ray astronomy, check out this excellent page at the University of Cambridge.

Shanil Virani