Chris Lintott’s Universe

I’m still in the US, where we’ve been filming pieces for the next few Sky at Nights. I need to write up the amazing two days we spent in mission control for Phoenix, but for now the Discovery blog has details of the Large Binocular Telescope and the alien-hunting Allen Telescope Array.

Having left the Sky at Night team crowing about their upgrade to first class on the way home and have headed off to visit Pamela. I’m giving a public talk tomorrow (Monday) night about Galaxy Zoo and citizen science more generally, and for those who can’t join us we’ll be broadcasting the event online.

The link is here, although you should be able to watch and chat below. The talk starts at 7pm Central, 1am Tuesday morning BST and midnight GMT.

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I’m shortly off of my travels again, recording interviews for Sky at Night in California and Arizona. On the way back, I’m visiting Pamela of astronomycast fame to work on a few projects. If anyone lives in or around St Louis, U.S.A., then you might be interested, nay, delighted, to know that you can come and listen to me talk about Galaxy Zoo and related issues on the evening of June 30th. Details are over here - and we’ll try and ustream the talk for those who can’t make it.

At any conference there’s one talk that changes the way you think about something, or crystalizes thoughts that you’ve had anyway. In the last few months I’d been thinking carefully about the answer to the question ‘but what happened before the Big Bang’, and a talk by Cosmic Variance blogger Sean Carroll crystalized some of those thoughts. He was clear that he was on the edge of speculation at times, but you can read the short version of my thoughts at the BBC website.

I’ll write more about my thoughts here over the weekend, so watch this space.

Update : Woo! Number 1 most emailed article…

This morning has been insanely busy; rewriting my talk which I’m giving tomorrow in the light of the results of the Galaxy Zoo bias study hasn’t helped. (You can see the latest here.) I did manage to sit in on an excellent press conference this morning though; the highlight was the results from the STAGES survey of a galaxy supercluster. Pamela sums up my feelings here. Oh, and there was a double Einstein ring, too.

My first AAS post was a nod to the talk I’ve just been to, a review of how astronomers meet their end by Thomas Hockney of the University of Northern Iowa. I was standing at the back having just come from another session, and so didn’t catch the names but here are the highlights:

First, the good news. Most astronomers die from natural causes. The most notable exception is probably Giovanni Bruno who was burnt at the stake. Dr Hockney noted, though, that maybe he shouldn’t be considered an astronomical martyr, having been killed for heresy not astronomy, and that he in fact deserved little sympathy having returned to Rome. As Hockney commented, any sane person should at least expect the italian inquisition.

The catalogue of slaughter included the Soviet astronomer killed in one of Stalin’s purges who unfortunately implicated the rest of his observatory staff as spies before he went, the asteroid hunter killed while one discovery away from his 100th minor planet, the great Persian astronomer Ulugh Beg who, killed by his son, goes down as the only astronomical patracide (to date) and many, many more…

Astronomy can sometimes feel like an arms race between observers and theorists. Both groups are often convinced that they’re completely right and - at least over a drink at the end of the day - take great pride in being ahead of the game. The latest battleground is in the field of extrasolar planets, and results from this lunchtime’s press conference will have cheered both sides.

Rory Barnes of the University of Arizona scored an early goal for the theorists, proudly announcing the first successful prediction of a planet since Neptune was discovered more than 160 years ago. His theory suggests that systems with multiple planets are often dynamically unstable, meaning that a small change in their orbits would lead to chaos. He also suggested that all such positions tend to have planets - solar systems tend to be ‘packed’. The system he studied, HD 74156, was already known to have two planets, and computer simulations indicated the presence of a gap. Sure enough, a couple of months ago, a planet was found in the gap just as Barnes predicted. Sara Seager, who gave an excellent talk on the field yesterday, congratulated him, and pointed out that this field littered with predictions which turn out to be wrong - but not this one.

Any theorists who were looking forward to the full time whistle should have listened to Carl Melis’ talk just a few minutes later. Looking through an old data set (from the IRAS satellite which went into orbit in 1983). His team have found two very confusing stars. They look like a type of young star called classical T Tauri stars, which have dusty disks, jets and lots of infrared light (see image above). So do the two stars Melis was studying, but there isn’t much lithium in them, which indicates that they are old. (Stars `burn’ lithium so its concentration should be highest when they’re young). So these are old stars pretending to be young, and possibly undergoing a second wave of planet formation. No-one predicted this, and I’m looking forward to seeing what the reaction might be and what explanations people will come up with.

I spent the morning in the science session devoted to galaxy morphologies – shapes- and environments and the lunch break with my press hat on listening to the latest results from Hubble (the telescope, not the astronomer; even a repair mission won’t help him now). There was lots of good stuff at both, but three items in particular grabbed my attention.

The first was the talk by Preethi Nair from the University of Toronto who has classified 15,000 of the brightest Sloan galaxies by eye. Her classification is much more detailed than ours, and includes many of the things we’ll try to do with Zoo 2 when it launches (hopefully in a month or so). The important thing from our point of view is that she agrees that visual classification makes a huge difference to the results; she found 20% difference between her ellipticals and those classified by looking at the concentrations of the galaxies. (Ellipticals – on average – are more concentrated – there’s more stuff in the middle – than spirals).

The second came in the press conference talk by Duilia de Mello. Her group have been studying a ‘blue blob’ near the classic spiral galaxy M81, which turned out to be a group of stars forming outside the main disks, probably as a result of interaction between M81 and its neighbours, the most prominent of which is M82. Indeed, Hubble images show some older stars which date to the time of the last major interaction between the systems.

The story of the blue blob should be ringing bells for all of you who read the Galaxy Zoo forum. We’ve been puzzling about a blue blob known as Hanny’s Voorwerp for a while, and on face value it does look like the blue blobs discussed by de Mello’s team. We’re working on getting a quick spectrum of the Voorwerp; the other possibility is that it’s a distant galaxy from which we’re only seeing one spectral line. Either way, it’d be great to find out which.

Finally, a cautionary tale from Gene Byrd. He was talking about NGC4622, a seemingly ordinary spiral galaxy. The only problem is that its two outer arms are rotating in the opposite direction to the two inner arms Byrd’s team managed to identify via some very clever image processing. Some of our GZ results assume that our results assume that the direction the spiral arms are pointing tells us about the direction of rotation of a galaxy. Most (more than 90% of galaxies do), but this sort of thing is a reminder that we don’t really understand spiral arms at all.

Update : You really should keep an eye on the hard work being done over at the Astronomy Cast conference page. With multiple people covering (almost) all the things going on at the meeting, this is the future of reporting from big conferences like this. And I’m not just saying that because they’re hosting drinks later this evening.

I’ve said again and again that the most exciting area of observational astronomy at the moment is the search for extrasolar planets. It’s incredible to think that in not much more than a decade we’ve moved from finding the first planet in a solar system other than our own to having several hundred in the catalogues. It’s fitting that the first science talk of the meeting, by James Kasting of Penn State, dealt with exactly that. While he talked about lots of the exciting results, it also proved an excellent reminder of just how hard it is to get science done sometimes. With the honourable exception of Kepler, due for launch next year (which he mentioned) and the French COROT mission which I don’t think he did, most of the planned planet seeking missions are either under review or postponed, both in Europe and the US.

Meanwhile, the brave planet hunters soldier on, looking for the first rocky planets in the habitable zone of their star (or, as I prefer, the Goldilocks zone - not too hot, not too cold). Some thought we’d got there with the discovery of Gliese 581c last year, but new results Kasting talked about show that’s it’s too warm, receiving 30% more light from its parent star than Venus does. Time to keep looking…

Update : More detailed lecture blogging here.

Astronomers do not easily get up for an 8am start. I’m sitting in the main meeting room and they’re can’t be more than 100 of the few thousand attendees here…

Seven of the Galaxy Zoo team are gathered in Portsmouth today for our first science meeting. The plan is to go through all of the hard work we’ve been doing to analyise the results and see what we agree on - and what we don’t. Sadly we can’t invite the more than 100,000 people who have contributed to the meeting, but we’ll try to keep you up to date here. I’ve turned off comment moderation, so feel free to join in.

10.07 : Typical organised start to a meeting; currently everyone is running around trying to connect their laptops to the internet while Steven is downstairs printing draft copies of the papers and Edd is making coffee for us visitors. Personally, three donuts have been consumed so I’m waking up. More soon.

10.18 : Starting 18 minutes late is probably a record. Bob has just announced he’s paying for lunch.

10.57 : I’ve just presented my paper, which will be an introduction to the project. The bottom line is that there are many different ways to go from clicks on a website to a final catalogue, and that understanding the biases in each is difficult. In particular, the fraction of galaxies which are classified as elliptical is very sensitive to what decisions we make. However, if we require a high level of agreement we get results that agree with other professional data. Other people can then use the results to do interesting science - over to Steven.

11.07 : Steven’s job has been to work out where ellipticals and spirals live. We know that you’re more likely to find ellipticals in the heart of clusters, but quantifying that in the nearby Universe is hard because you have to look across large regions of sky, which is exactly what Sloan and hence Galaxy Zoo does.

11.18 : …it turns out that comparing to high redshift results is difficult. If I’m understanding the discussion correctly, the problem is defining how dense an environment actually is. Is it enough to count how many neighbours, or do we need to something more complicated?

11:42 : If you take the data at face value, the fraction of galaxies which are classified as elliptical changes rapidly with redshift (distance). This isn’t true if you only look at the brightest galaxies, suggesting it’s just the tendency of people to see faint fuzzy things as elliptical. However, Steven can account for this by correcting to match the results from the closest galaxies of a particular brightness.

12.15 : We’ve moved on from talking about the main population of galaxies to the weird and wonderful. Kevin has been collecting the bluest ellipticals in the sample; remember this was one of the main points of Galaxy Zoo. Most elliptical galaxies formed their stars in the early Universe and are now ‘red and dead’. Elliptical galaxies which are blue might be late developers, allowing us to see stars forming in elliptical galaxies today.

12:39 : Yey, we find lots of blue ellipticals. Many more than anyone else has, and lots of them are pretty close (so we can be sure that we’re not confusing faint fuzzy spirals with ellipticals again). We immediately plunge into an argument as to what these strange objects actually are.

12.45 : I may be becoming flippant (blood sugar from donuts is all but gone) but I think we agree we don’t know what these are, and that that’s what we’re excited about. Bob’s talking next but has run away.

12.47 : He’s back, but we’re back to arguing about what these blue ellipticals are, particularly about how to compare to computer simulations. Bob’ll be talking about our other set of weird galaxies - red spirals.

12.57 : Bob’s now standing up, and we’re still arguing about what the blue ellipticals are. It’s his own fault, though. OK, he’s now moved on.

13.04 : Here there’s more confusion - distinguishing between true spirals, and galaxies which have no spiral arms but do have a disc - is all important. Not all of them can be explained away by this, though.

13.11 : Off to lunch to argue about those results. Back about 2.

14.14 : Back from lunch, and just setting up conference calls to other team members who couldn’t be in Portsmouth today. - Edd

14.18 : One of the other interesting parts to the Zoo is the social science side - looking at the users rather than the galaxies, user demographics, motivations and so on. Jordan’s giving us a rundown. - Edd

14.37 : Jordan’s telling us his plans for surveys of users. It’s not only sounding interesting, but also useful in keeping the Zoo something everyone enjoys using. - Edd

14.43 : And moving on to talk about our plans for the next phase of Galaxy Zoo - Edd

As a who’s who - the last pic, Chris has is back to you all, with Kate on the left. Then it’s Kevin, Daniel and me on the far right. The middle one’s from the other side, and you can see Steven at the back on the left. Bob’s not pictured - he’s the man with the camera. - Edd

15.25 : And Kate is now telling us about the mysteries of spiral handedness… - Edd

16:25 : Which caused a huge argument - all good fun. Some of us have to head home, others to the pub. Thanks for joining us. Chris