PSA: Bars Kill Galaxies

Barred Spiral Galaxy NGC 6217
Barred Spiral Galaxy NGC 6217


Many spiral galaxies are known to harbor bars. Not the sort in which liquor is served as a social lubricant, but rather, the kind in which gas is served to the central regions of a galaxy. But just as recent studies have identified alcohol as one of the most risky drugs, a new study using results from the Galaxy Zoo 2 project have indicated galactic bars may be associated with dead galaxies as well.

The Galaxy Zoo 2 project is the continuation of the original Galaxy Zoo. Whereas the original project asked participants to categorize galaxies into Hubble Classifications, the continuation adds the additional layer of prompting users to provide further classification including whether or not the nearly quarter of a million galaxies showed the presence of a bar. While relying on only quickly trained volunteers may seem like a risky venture, the percentage of galaxies reported to have bars (about 30%) was in good agreement with previous studies using more rigorous methods.

The new study, led by Karen Masters of the Institute of Cosmology and Gravitation at the University of Portsmouth, analyzed the presence or lack of bars in relation to other variables, such as “colour, luminosity, and estimates of the bulge size, or prominence.” When looking to see if the percent of galaxies with bars evolved over the redshifts observed, the team found no evidence that this had changed in the sample (the GZ2 project contains galaxies to a lookback time of ~6 billion years).

When comparing the fraction with bars to the overall color of the galaxy, the team saw strong trends. In blue galaxies (which have more ongoing star formation) only about 20% of galaxies contained bars. Meanwhile, red galaxies (which contain more older stars) had as many as 50% of their members hosting bars. Even more striking, when the sample was further broken down into grouping by overall galaxy brightness, the team found that dimmer red galaxies were even more likely to harbor bars, peaking at ~70%!

Before considering the possible implications, the team stopped to consider whether or not there was some inherent biasing in the selection based on color. Perhaps bars just stood out more in red galaxies and the ongoing star formation in blue galaxies managed to hide their presence? The team referenced previous studies that determined visual identification for the presence of bars was not hindered in the wavelengths presented and only dipped in the ultraviolet regime which was not presented. Thus, the conclusion was deemed safe.

While the findings don’t establish a causal relationship, the connection is still apparent: If a galaxy has a bar, it is more likely to lack ongoing star formation. This discovery could help astronomers understand how bars form in the first place. Given both structure, such as bars and spiral arms, and star formation are associated with galactic interactions, the expectation would be that we should observe more bars in galaxies in which interactions have caused them to form as well as triggering star formation. As such, this study helps to constrain modes of bar formation. Another possible connection is the ability of bars to assist in movement of gas, potentially shuttling and shielding it from being accessible for formation. As Masters states, “It’s not yet clear whether the bars are some side effect of an external process that turns spiral galaxies red, or if they alone can cause this transformation. We should get closer to answering that question with more work on the Galaxy Zoo dataset.”

The Sloan Digital Sky Survey: “A Grand and Bold Thing”

If you do a search of articles on Universe Today, you’ll find that a large number of our posts reference the Sloan Digital Sky Survey. SDSS is a comprehensive survey to map the sky, using a dedicated 2.5 meter telescope equipped with a 125- megapixel digital camera and spectrographs. Since 2000, SDSS has created terabytes of data that include thousands of deep, multi-color images, covering more than one-quarter of the sky. SDSS is literally changing the way astronomers do their work, and represents a thousand-fold increase in the total amount of data that astronomers have collected to date. In a new book, “A Grand and Bold Thing; An Extraordinary New Map of the Universe Ushering in a New Era of Discovery,” science journalist Ann Finkbeiner tells the story of how SDSS came about (frighteningly, the survey almost didn’t happen), delving into some of the discoveries made as a result of this survey, and sharing how even armchair astronomers are now probing the far reaches of the Universe with SDSS.

SDSS has measured the distances to nearly one million galaxies and over 100,000 quasars to create the largest ever three-dimensional maps of cosmic structure. It also spawned one of our favorite citizen science projects: Galaxy Zoo.

For three years, Ann Finkbeiner researched and interviewed astronomers to get the story behind SDSS, to tell the little-known story of this grand project, and how it soon grew into a far vaster undertaking than founder Jim Gunn could have imagined. The book is extremely readable, and Finkbeiner captures the personalities who brought the project to life. If you thought Earth-based observing was passe, this book will make you re-think the future of astronomy.

Finkbeiner is a freelance science writer who has been covering astronomy and cosmology for over two decades. She has written feature articles for Science, Sky & Telescope, Astronomy, and more, with columns for USA Today, and Defense Technology International. She is co-author of The Guide to Living with HIV Infection (Johns Hopkins University Press, 1991; sixth edition, 2006), which won the American Medical Writers Association book award. She is also author of “After the Death of a Child,” and “The Jasons,” which won the American Institute of Physics’ Science Writing Award in 2008.

Below is a Q & A with Finkbeiner about “A Grand and Bold Thing.”

Q: What made you first want to write this book?
A: I was finishing a magazine article about the Sloan Digital Sky Survey just as I was beginning the interviews for a book—The Jasons—for which no one at all wanted to talk to me. But the Sloanies I was interviewing were so happy about what they were doing, so intense about it all, and so open (they even showed me their gazillion archived emails) that writing a book about them felt like it would be a blessed relief, like leaving boot camp and going to a good block party.

I was writing the magazine article in the first place because I’d attended a talk by Jim Gunn at Johns Hopkins, and while I listened, I realized I hadn’t heard any news from him for a long time. So I afterward, I asked him why he’d gone off radar. He told me he’d been working on getting a survey going, using a little 2.5 meter telescope, and I wasn’t impressed. I thought it was an odd use of his splendid capabilities. I was impressed later, though, when he stayed off radar and I found out that other excellent scientists were doing the same. I started wondering why they were giving up their careers for a sky survey.

Q: Has perception of the project changed from the time you first started writing about it until now?
A: Between the time I first heard about it—in the late 1990’s—and the present, the perception of the project changed dramatically: today, it’s hard to overstate its importance. But astronomers’ early reactions to the survey were what mine had been: Little telescope. Not spectacular resolution. Can’t go very deep in the past. Astronomers who knew the value of a survey and Jim’s reputation for building nearly-perfect instruments were quicker to see the potential, but the project’s many, many management problems led to the community taking pot shots at the Sloanies. Then when funding agencies started refusing to give astronomers money because the Sloan was going to do their pet projects better than they would, Sloan became a dirty word. Now, astronomers say it changed the way they do their work.

Q: What do you think have been the most important benefits of the Sloan Survey’s completion?
A: The Sloan was, and still is, the only systematic, beautifully-calibrated survey of the sky and everything in it. And it’s the first survey to be digital. Astronomy before Sloan was photographic, meaning you were at a rich university that owned a telescope, you decided which objects in the sky you liked and took photographs of them, and kept them for yourself. If you wanted to use the only survey of the sky, you bought expensive photographs of it. After the Sloan, you download the objects you want to study onto your computer for free. So whether you’re an astronomer or a regular person, you can study anything you want to with some of the most trustworthy data going. And if you don’t want to learn astronomy jargon and query languages, you can go to and join the 300,000 people doing astronomy on the Internet using this data. The Sloan has democratized astronomy. It’s made “citizen science” real. And it’s about to become redundant because it triggered a population of other newer, bigger surveys.

Q: What do you think the story of the Sloan Survey tells us about current cosmological thought?
A: Before Sloan, cosmology was seen as a fluffy science: the universe is big, distant, and hard to observe, so the phrase “precision cosmology” would have been an in-joke. But Sloan’s data is so comprehensive and exquisite that precision cosmology is now the norm.

Before the Sloan, cosmology was fractured into many fields whose relation to each other wasn’t obvious and wasn’t being studied. Sloan found all kinds of things in all areas of astronomy: asteroids in whole families, stars that had only been theories, star streams around the Milky Way, the era when quasars were born, the evolution of galaxies, the structure of the universe on the large scale, and compelling evidence for dark energy. So after the Sloan, cosmologists began seeing the universe as a whole, as a single system with parts that interact and evolve.

Q: Work like this costs an enormous amount of money, but doesn’t yield the sort of practical results the average American can see. What is the best argument to continue funding science like this?
A: The main Sloan survey cost $85 million over 10 or 15 years. In the realm of government budgets, that’s spare change. It cost so little partly because the scientists gave their time for free—they had university salaries already. And since this free time came at the expense of their own research and personal reputations, they’re a case study in altruism. In addition, the universe is mankind’s most fundamental context; and astronomy and cosmology have, I think, some of the appeal of philosophy and religion. Put scientific intelligence together with altruism and questions of origin and place in the universe, throw in beautiful pictures, and I’d give it money in a minute.

Q: There are a lot of good stories behind the making of the Survey. What are some of your personal favorites?
A: My all-time favorite is Galaxy Zoo, which started when a couple of Sloanies needed to know which galaxies were spirals, which were ellipticals, and which were irregular. But Sloan had a million galaxies, which is a lot for any human to sort through: computers are no good at identifying shapes, humans are superb at it. So the Sloanies put the million galaxies on the internet, asked for help, and within a day, their computer server melted. There are now 300,000 Galaxy Zooites of all ages, all levels of education, from all over the world, and they’ve gone way beyond classifying shapes. Hanny van Arkel, a Dutch primary school teacher, found a strange blue object the Zooites called Hanny’s Voorwerp, and after followups with xray, ultraviolet, and radio telescopes (not to mention the Hubble Space Telescope), the Voorwerp turned out to be a place in an enormous cloud of gas which was being hit by a hard xray jet from a galactic-sized black hole. Zooites also found a new kind of greenish, round galaxy, and then found enough of them that they’re now officially called Green Pea galaxies. Green Peas turn out to be small, nearby, previously unknown galaxies in which stars are being born at a furious rate. Then Zooites went off and taught themselves serious astronomical techniques and began collecting and studying irregular galaxies; astronomers knew of 161 irregulars, the Zooites found 19,000 of them and called their project, Do It Ourselves.

I also love Jim Gunn’s professional trajectory from fame to invisibility, and while invisible, his fight-starting and progress-impeding insistence on doing everything as well as it can possibly be done. When Jim started the Sloan, he was extremely famous and highly respected. He walked away from his own research and spent the next 30 (he’s still doing it) years first putting together the collaboration, then building the camera, while also overseeing and micromanaging every detail of every piece of hardware, software, and politics. He’s a perfectionist whose motto is: “if you don’t do it right to begin with, you’ll have to do it again, no matter what the bloody cost and schedule says.” He caused no end of arguments, particularly when the “young astronomers” involved adopted the same motto. The perfectionism was finally controlled, on the surface anyway, by a remarkable project manager, but Jim and the young astronomers kept doing it right on their own time and without permission. The Sloan’s whole value today is that it’s nearly perfect, and this precision has enabled much of its most important contributions. Jim’s now nominally retired and in any case, has turned the survey over to the young astronomers who have, in their turn, turned it over to the whole astronomical community and to the public.

Q: One thing that might surprise readers is how “political” scientists sometimes have to be in working with their colleagues, other institutions, and even asking for funding. Why is this, and has it always been this way?
A: It’s been that way ever since science stopped being a gentleman’s hobby—Jim’s phrase, “gentleman astronomers in their coats and ties”—and began getting funding from foundations and the government. The amount of funding is limited and everyone has to complete for the same small, fixed pot. It’s hair-raising. The astronomical community solves this brilliantly: they find out what everybody else is doing, then they do something different and complementary, and finally they get together and tell the funders what the community’s priorities are. The result is that astronomy keeps getting funded. Meanwhile, individual astronomers are free to be competitive and dog-eat-dog, just as their human nature requires.

Q: What do you hope readers take away from this book?
A: The joy and entertainment of watching these impressively intelligent and persistent guys fumble around until they’ve done something remarkable.

Citizen Science Goes to the Moon

Screen shot from Moon Zoo.


Have you ever wanted to explore the Moon? Well, now you can as a virtual astronaut, and you can help lunar scientists answer important questions, as well. New from the Zooniverse — from the same folks that brought you Galaxy Zoo — is Moon Zoo. “We’re asking citizen scientists to help answer different aspects of lunar science and outstanding questions that we still have,” said Dr. Katherine Joy from the Lunar and Planetary Institute and a Moon Zoo science team member.

Moon Zoo uses about 70,000 high resolution images gathered by the NASA’s newest lunar spacecraft. the Lunar Reconnaissance Orbiter. In these images are details as small as 50 centimeters (20 inches) across, and ‘Zooites’ are will be asked to catergorize craters, boulders and more, including lava channels and even all sorts of different spacecraft sitting on the Moon’s surface.

How fun is this latest Zoo project?

“Actually, I have to say after a few days of playing with it I find it much more addictive than the others,” said Chris Lintott, head “zookeeper” of the Zooniverse and chair of the Citizen Science Alliance. “Galaxy Zoo was bad enough but I’m obsessed with the Moon now. I can’t quite believe the variety of the places we’re seeing. People think the Moon is this boring place – they say, ‘we know what it looks like, it’s just grey and flat, right?’ But actually it has its own landscape that is really quite dramatic, especially when the sun is low, so it’s a world well worth exploring.”

Want to join in? Go to the Moon Zoo website, and if you’ve participated any of the previous Galaxy Zoo or Solar Storm Watch projects, you can use the same username and password. If not, it’s easy to sign up.

Under the “How to Take Part” tab you’ll find a tutorial that will teach you how to participate in Moon Zoo.

The two main biggest tasks right now are the Crater Survey, where you can mark all the craters (down to a certain size), and Boulder Wars, where you are shown two images and you determine which has the most boulders.

But Dr. Joy said there will soon be some additional tasks, created from a wish list from lunar scientists. “One of the main tasks we really want to do is to compare these new LRO images to older Apollo panoramic camera images that were taken 40 years ago,” she said. “And what we can do is match these older images against the new images with similar lighting conditions and similar angles at which the camera was pointed at the surface and what we might be able to do is to spot differences that have occurred between 40 years ago and now, which could be in the form of say, new impact craters that have formed from incoming bolides. We might be able to spot new debris flows and landslides that have happened in the past 40 years. This can provide us information about the really recent history of the Moon.”

Questions? There’s a FAQ section and a discussion forum where you can pose queries or discuss any issues or interesting finds with other Zooites.

“We’re hoping to reach out to people that have never really looked at the Moon before in any kind of detail and get them excited about all the secrets the Moon still has,” said Dr. Joy “because there are plenty of new things that people have never looked at before.”

Listen to the May 19, 2010 edition of the 365 Days of Astronomy podcast for an interview with Katie Joy and Chris Lintott.

Astronomers Begin Observing Hanny’s Voorwerp with the Hubble Space Telescope

The green "blob" is Hanny's Voorwerp. Credit: Dan Herbert, Peter Smith, Matt Jarvis, Galaxy Zoo Team, Isaac Newton Telescope


The green “blob” is Hanny’s Voorwerp. Credit: Dan Herbert, Peter Smith, Matt Jarvis, Galaxy Zoo Team, Isaac Newton Telescope

A storybook astronomy mystery is now part of the most famous telescope in history. A team of astronomers secured time on the Hubble Space Telescope to observe Hanny’s Voorwerp, the unusual object found by Dutch teacher Hanny Van Arkel while she was scanning through images for the Galaxy Zoo project. Hubble will be trained on the Voorwerp during three separate observing sessions, the first of which occurred on April 4, 2010. “The WFC3 (Wide Field Camera 3) images were obtained (Sunday),” said Principal Investigator Bill Keel from the University of Alabama in an email to Universe Today “and I was able to pull the calibrated files over last night for a quick look. Combining pairs of offset images to reject cosmic rays optimally will take some further work, but we’re happy to start working with the data and see what emerges at each step.”

The Voorwerp (also known by the much less endearing name of SDSS J094103.80+344334.2) created a sensation among amateur, armchair and professional astronomers alike, almost immediately after Van Arkel saw the object in 2007 and posted a question on the Galaxy Zoo forum, asking “What is this?” All this took place just a month after the Galaxy Zoo project opened up their online citizen science shop, and the rest is history. But in case you haven’t heard the story yet, a quick rundown is that ‘voorwerp’ means ‘object’ in Dutch – and as of yet, no one has determined exactly what Hanny’s Voorwerp is.

The working hypothesis, according to the Galaxy Zoo team, is that Hanny’s Voorwerp might be a “light echo” of an event that occurred millions of years ago. The object itself consists of dust and gas which perhaps was illuminated by a quasar outburst within the nearby galaxy IC 2497 (see the images). The outburst has faded within the last 100,000 years but the light reached the dust and gas in time for our telescopes to see the effect.

Hanny's Voorwerp. Credit: Matt Jarvis, William Herschel Telescope.

The Galaxy Zoo images come from observations done by the Sloan Digital Sky Survey. In evidence of the interest in this object, since 2007 Hanny’s Voorwerp has also been imaged by the Swift gamma-ray satellite, the Suzaku X-ray telescope, the Westerbork Synthesis Radio Telescope (WSRT), the Issac Newton Telescope and the William Herschel Telescope, to name a few.

But now, the most famous telescope of all – with its new and updated instruments – will take a gander to see if the mysteries of the Voorwerp can be solved.

The team – which includes Keel, and fellow Galaxy “Zookeepers” Chris Lintott, Kevin Schawinski, Vardha Nicola Bennert, Daniel Thomas, and Hanny Van Arkel herself – submitted a proposal to the Space Telescope Science Institute back in 2008 and were among the proud and few from close to 1000 proposals submitted to be granted observing time on Hubble.

During the three observing sessions, three different Hubble instruments will be used.

“The observations use three instruments and would naturally be broken into three target visits,” said Keel, “some constrained to be at different times because of the required orientations on the sky –for example, to have both Hanny’s Voorwerp and IC 2497 in the narrow field of view of ACS (Advanced Camera for Surveys) with the monochromatic ramp filters.”

“The next observations will probably be the most visually striking,” Keel continued. “Two orbits’ worth of ACS images in narrow bands including [O III] an H-alpha emission, and are scheduled for April 12. The final visit in the program has 2 orbits of STIS (Space Telescope Imaging Spectrograph) spectroscopy around the nucleus of IC2497, and should be coming up by mid-June.”

The April 4 observations included three orbits of data from the WFC3.

So, even though the first images have now been seen, the team won’t be able to share their findings until all the observations have occurred and the data has been analyzed.

Hanny Van Arkel. Image courtesy of Hanny.

“I indeed can’t say much more than that we got the first data in our mailboxes,” Van Arkel said in an email to Universe Today. “The team is still working on it and until they’ve worked it out, I won’t even understand enough of it myself to explain anything on the matter. It is exciting however that the investigations have started and it’s nice to see how many curious people are sending me messages about it and ‘retweeting’ my quotes on Twitter. After almost two years, I’m very much looking forward to the outcome of all of this!”

Van Arkel isn’t the only one excited.

“Through a combination of geometry and weather,” Keel shared,”I saw HST sail by to our south less than two orbits after it finished this first data set. So I waved in what was probably a most unprofessional manner.”

And the rest of us will be waiting – and waving – until Hubble can tell us more about Hanny’s Voorwerp.

For more information:

Hanny Van Arkel’s website

A post on the Galaxy Zoo blog by Bill Keel explaining in greater detail the Hubble observing sessions.

Galaxy Zoo

For other citizen science projects, visit the Zooniverse

Galaxy Zoo is Expanding to Include a Whole New “Zooniverse”

Galaxy Zoo has been an enormously successful citizen science project; so much so, that other astronomers, as well as scientists from other disciplines, have taken notice and now they want to get in on the act of having the public help make discoveries about our world and Universe. Today, the Galaxy Zoo team has launched Zooniverse. This new website will be a platform, or “home” to a plethora of new science projects where the public can take their pick of where and how they can make meaningful contributions and discoveries.

Zooniverse became inevitable around the time that Galaxy Zoo launched in 2007,” said Chris Lintott, one of the founders of the original Galaxy Zoo, and now Zooniverse, “because it was obvious a few hours into the first day that we had hit on a way of doing science that was really powerful. And it was clear that this was not only going to work with for galaxies, but for other science as well. Soon we’ll we have solar investigations, climate science, and a lot of other citizen science projects coming online.”

For those “Zooites” who love Galaxy Zoo – don’t worry, that project isn’t going anywhere.

“Galaxy Zoo itself will remain the sort of comfortable old sofa in the corner,” Lintott told Universe Today, “so anyone who is comfortable with that can remain sitting there, classifying galaxies and discovering things. But for people who want to explore a bit further and find new and exciting places to be, we’re going to expand the Zooniverse by pointing some new data to the sofa.”

On Dec. 16 an astrophysics project will be introduced in Beta to people already involved in Galaxy Zoo and the offshoot projects: Galaxy Zoo 2, Supernova Hunt, and Galaxy Mergers. If all goes well, it will be launched “live” to the public early 2010.

With new advanced instruments and ways of gathering data, scientists in almost all disciplines are inundated with data but don’t have an efficient way to sort through, organize and classify the information. Galaxy Zoo’s success (over 51 million classifications by over 250,000 people, as well as new discoveries and several science papers published) has attracted the attention of other scientists, many who have contacted Lintott and his team, wondering if there was any way they could use that same model to have the public help with other unique science tasks.

Lintott said they have a long list of additional projects that are already under development. “In a couple of years’ time we should have some wonderful projects come online, such as studying ancient artifacts, oceanography projects, looking at Earth from space, animal behavior projects, and more. We keep getting new really great projects contacting us all the time.”

“We’ve known this has been coming for years, but we didn’t really know how to do it,” said Arfon Smith from Oxford University, one of the developers of the Zooniverse site, who has been working on how to integrate other science projects into the Galaxy Zoo model. “We needed a big project to come along that wasn’t dealing with galaxies to actually get us pointed in the right direction. The technical challenge was to make the Zooniverse a nice place to be, and to make it easy for users to move between the different ‘Zoos.'”

If you are registered on Galaxy Zoo, you’ll notice you can now access and seamlessly move between Galaxy Zoo, the Mergers and Supernova Hunt sites without re-logging in. The same will hold true for the new science projects that will be coming online on the Zooniverse in the coming months and years.

“There’s an opportunity here for people to explore a range of citizen science projects,” said Smith. “Zooniverse will be a place where people can check to see what projects they might want to work on.”

“The common thread is that each project needs the public’s help to increase our understanding of the Universe, and each will produce results that could not happen without the public,” said Lintott. “Soon, there should be a science project for everyone’s interests.”

Lintott said Universe Today readers will have to wait a little while to see what they actually are, but we will definitely keep everyone updated on the new citizen science projects as they become available.

Alongside the Zooniverse, another new website, Citizen Science Alliance, has been launched for the organizations who will be coming to the Zooniverse. “The Citizen Science Alliance involves our partners,” said Lintott, “and all of us believe that making use the public’s skills, talents and energy is not only helpful in dealing with the flood of data confronting us, but it is necessary.”

Source: interview with Chris Lintott and Arfon Smith

Try Your Hand At Galaxy Zoo’s New “Slot Machine”

Galaxy mergers, such as the Mice Galaxies will be part of Galaxy Zoo's newest project. Credit: Hubble Space Telescope
The Mice galaxies, merging. Credit: Hubble Space Telescope

Here’s your chance to play online slot machines without risking your life savings. Plus it’s an opportunity to contribute to a citizen science project that is sure to revolutionize our understanding of galaxy mergers. Galaxy Zoo’s newest project asks for help in looking at colliding galaxies, and uses a tool akin to a cosmic slot machine to compare images of galactic pile-ups with millions of simulated mergers.

“The analogy I’ve been using is that it is like driving past a car crash,” said Galaxy Zoo team member Chris Lintott from Oxford University. “You get a snapshot of the action, but there are two things you want to know: what caused the crash (or what did things look like before it all went wrong), and you want to know what the outcome is going to be. We’re doing the same thing. We want to know what the galaxies looked like before the mergers started disrupting them, and we want to know how they are going to end up. Just like our other Galaxy Zoo projects, humans are much better at doing this than computers, and lots of humans are even better.”

The Galaxy Zoo mergers project goes live on November 24 at

“This is another classic Galaxy Zoo problem,” Lintott told Universe Today. “We found 3,000 galaxy mergers from Galaxy Zoo 1, and we don’t have a good understanding of the processes that take place during and after the collisions. This new project will help us work that out.”

On the Galaxy Zoo Mergers page, there will be a real image of a galactic merger in the center and with eight randomly selected merger simulations filling the other eight ‘slots’ around it. Visitors to the site pick which animation best demonstrates what is happening in that collision. But if they don’t see a good simulation, they can “spin the wheel again,” Lintott said, until a good depiction of the merger shows up.

A Grazing Encounter Between Two Spiral Galaxies (NGC 2207 and IC2163).  Credit: HubbleSite
A Grazing Encounter Between Two Spiral Galaxies (NGC 2207 and IC2163). Credit: HubbleSite

“By randomly cycling through the millions of simulated possibilities and selecting only the very best matches the users are helping to build up a profile of what kind of factors are necessary to create the galaxies we see in the Universe around us — and, hopefully, having fun too,” Lintott said.

There’s also the “enhance” option, where you can take control. “Once you have picked a simulation, you can take control of it directly, and change the parameters by hand such as the size, mass, the speed, for example. So, if you get impatient you can take control and see if you can do a better job than the slot machine,” Lintott explained.

For some of mergers, there will be a unique solution – only one way to get the merger we see today. For others there may be many different simulations that could provide the answer.

The Mergers project is a bit different than the regular Galaxy Zoo in that there will be, initially, just one daily challenge. “We’re aiming for one a day, but obviously if everyone who reads Universe Today turns up, we’ve got an idea of how many people we need to look at each one, so then we’ll change them out quicker,” Lintott said. “The more that people do, the more galaxies they’ll get to see.”

Of course, galaxy mergers are beautiful and amazing astronomical objects to behold, so the Galaxy Zoo team is hoping this will be a popular project.

“The point of Galaxy Zoo is to try and understand how we got the mix of galaxies that we see today,” Lintott said. “One of the mysteries is trying to work out how the ellipticals formed. We know that one way to form elliptical is to smash two spirals together. There’s the famous simulation of the Milky Way and Andromeda colliding and everyone assumes it will end up as a big elliptical that has used up all its gas. But actually it’s not clear how often that happens, and it’s not clear that you always get elliptical when you smash spirals together. In fact we know that in some cases they don’t. There is a lot of debate as to how important mergers are in this process.”

Right now, 3% of galaxies are in the process of merging, so, Lintott said, if most big galaxies undergo a merger every million years or so, this is clearly an important process.

“But we don’t understand what affects it has, and that’s what we hope to realize in this project.”

And Lintott admitted this newest Galaxy Zoo project is supposed to be fun and addictive. “Some people will love it, and some people will probably prefer the regular Galaxy Zoo. But it’s nice to have a range of scientific tasks that we have to work through.”

For more information:

Galaxy Zoo Mergers

Galaxy Zoo

Barred Spiral Galaxy

A barred spiral galaxy, from the Galaxy Zoo 2 tutorial (How to Take Part)

As its name implies, a barred spiral galaxy is a spiral galaxy with a bar through the center.

Hubble introduced the ‘tuning fork’ scheme for describing the shapes of galaxies (“morphologies” in astronomer-speak) in 1936. In this, the two arms of the fork are barred spirals (from SBa to SBc) and spirals without bars (from Sa to Sc); the S stands for spiral, B for ‘it’s got a bar’, and a/b/c for how tightly wound the spiral arms are. This was later extended to a fourth type, SBm and Sm, for irregular barred spiral galaxies which have no bulge.

In 1959, Gérard de Vaucouleurs extended the scheme to the one perhaps the most commonly used by astronomers today (though there’ve been some mods since). In this scheme spirals without bars are SA, and those which have really weak bars are SAB; barred spirals remain SB. He also added a ‘d’ (SAd, SBd), and a few other things, like rings.

About half of spiral galaxies are barred; examples include M58 (SBc), M61 (SABbc), the Large Magellanic Cloud (LMC, Sm), … and our own Milky Way galaxy!

The bars are mostly stars (usually), unlike spiral arms (which have lots of gas and dust besides stars). The formation and evolution of bars is an active area of research in astronomy today; they seem to form from close encounters of the galaxy kind (galaxy near-collisions), funnel gas into the central bulge (where the super-massive black holes there snack on it), and are sustained by the same density waves which keep the arms alive.

Why not join the Galaxy Zoo project, and have some fun classifying spiral galaxies into whether they have bars or not (and getting to see some amazing sights too)?

Hubble Early Release Observation of Barred Spiral NGC 6217, Two Galaxies Walk Into a Bar…, and The Milky Way Has Only Two Spiral Arms; just some of the Universe Today stories on barred spiral galaxies.

Astronomy Casts featuring barred spiral galaxies include The Story of Galaxy Evolution, and Galaxies.

Hunt for Supernovae With Galaxy Zoo

How would you like to find a supernova? I can’t think of anyone who wouldn’t be proud to say they have spotted an exploding star. And now, perhaps you can – and without all the work of setting up your telescope and staying up all night (well, that can be fun, too, but…). The great folks who brought you Galaxy Zoo have now partnered with the Palomar Transient Factory to offer the public a chance to hunt and click for supernovae from the comfort of your own computer. And yes, you can still classify galaxies at Galaxy Zoo, but now you can search for for the big guns out in space, too. Sound like fun?

The Palomar Transient Facory uses the famous Palomar Observatory and the Samuel Oschin 1.2 m telescope to look for anything that’s changing in the sky — whether it’s a variable star, an asteroid moving across the sky, the flickering of an active galaxy’s nucleus or a supernova. For now, though, the partnership with Galaxy Zoo will concentrate on finding supernovae, and in particular Type 1A supernovae.

According to Scott Kardel of the Palomar Observatory, “the quantity and quality of the new data that’s been coming in are absolutely mind blowing for astronomers working in this field. On one recent night PTF patrolled a section of the sky about five times the size of the Big Dipper and found eleven new objects.” For the supernova search, it returns to the same galaxies twice a night, every five nights.

That’s where the Zooites from Galaxy Zoo come in: searching through all specially chosen PTF data and looking for supernovae.

“Your task is to search through the candidates found by PTF” said the Galaxy Zoo team. “Waiting for your results are two intrepid Oxford astronomers, Mark and Sarah, who have travelled out to the Roque de los Muchachos Observatory on the Canary Island of La Palma. They have time allocated on the 4.2m William Herschel Telescope to follow up the best of our discoveries.”

Check out Galaxy Zoo’s Supernova page for more info and to sign up to be part of this exciting new Citizen Science project!

For more info on the Palomar Transient Factory, listen to Scott Kardel’s 365 Days of Astronomy podcast.