Bad Astronomy

Galaxy Zoo: what if you find something totally cool?

So you’re addicted to Galaxy Zoo, and while identifying galaxies hither and yon you found some killer cool galaxy image. Did you discover something new? Could this be the scientific breakthrough of all time?

Probably not. But it’s still wicked nifty, and you want to find out more. What to do?

Actually, it’s not too hard. What you need to find out is the name of the galaxy – really, the catalog number. If the galaxy is bright/big enough, it’ll be in some catalog like the New General Catalog or the Uppsala Galaxy Catalog.

The easiest way to find it is to use an astronomical database. Pretty much every object in the sky to a relatively faint limit is in a catalog somewhere, and a lot of these are online and searchable. The best bet is to use the coordinates of the object you found.

Astronomers use coordinates on the sky like longitude and latitude, but we call them Right Ascension and Declination. The Sloan survey used by Galaxy Zoo lists the coordinates in degrees; RA goes from 0 to 360, and Dec goes from -90 to 90 (just like Earth coords do). You can use these coordinates to find the galaxy, just like you can use long and lat to find, say, an island on Earth.

Let’s look at an example.

You’re tooling around Galaxy Zoo, and you spot this astonishing tableau. Wow! A collision between three galaxies, with the large one showing a very long tidal tail (extending well past the two smaller galaxies in the center).

If you are in Galaxy Zoo at the time, click the galaxy image to get a bigger version. Now look at the URL (or hover your mouse over the image and check out the address in the bottom of your browser). The last bit will have the RA and Dec! In this case, the coordinates part of the URL is

ra=213.44051502&dec=8.21870234

So the RA is 213.44051502 and the Dec is 8.21870234. The best place to go trolling for what this means is the French SIMBAD database. Once there, on the left is a link to search by coordinates (or you can go directly there). Cut and paste the coordinates into the text field – but make sure you leave a space between them, and make sure you put a “plus” or “minus” sign in front of the Dec (if there is no sign in the URL, then put a “+” there). Hit enter!

You may get a single hit, or there may be lots. Chances are there are only one or two. In the case of our interacting trio above, there are five separate names, but I suspect they all mean the same object (there are multiple catalog names for every object in the sky). I see a UGC number in this case, which is good; that’s a popular catalog. I dump the name UGC 9103 into Google, and the first hit returned is to SkyFactory! Win! That is a fantastic resource for images of the sky. The image isn’t as nice as the one from Sloan, but still, there you go. You can track the other catalogs as well and see if your galaxy turns up.

If you happen to get an NGC number, try the Interactive NGC database, too.

All in all, tracking down an interesting object isn’t that hard. And if it doesn’t show up anywhere, well, you might be onto something! Contact the Galaxy Zoo folks. But hold off on the Nobel Prize nomination committee just yet.