Galaxy Zoo 2 data release

It’s always exciting to see a new Galaxy Zoo paper out, but today’s release of our latest is really exciting. Galaxy Zoo 2: detailed morphological classifications for 304,122 galaxies from the Sloan Digital Sky Survey, now accepted for publication in the Monthly Notices of the Royal Astronomical Society, is the result of a lot of hard work by Kyle Willett and friends.

Lead author Kyle, seen here taking a rare moment away from reducing Galaxy Zoo data.

Galaxy Zoo 2 was the first of our projects to go beyond simply splitting galaxies into ellipticals and spirals, and so these results provide data on bars, on the number of spiral arms and on much more besides. The more complicated project made things more complicated for us in turning raw clicks on the website into scientific calculations – we had to take into account the way the different classifications depended on each other, and still had to worry about the inevitable effect that more distant, fainter or smaller galaxies will be less likely to show features.

We’ve got plenty of science out of the Zoo 2 data set while we were resolving these problems, but the good news is that all of that work is now done, and in addition to the paper we’re making the data available for anyone to use. You can find it alongside data from Zoo 1 at data.galaxyzoo.org. One of the most rewarding things about the project so far has been watching other astronomers make use of the original data set – and now they have much more information about each galaxy to go on.