SDSS Plate Graphics

I had an idle thought a couple weeks ago...

Wouldn't it be nice to see a picture of a Sloan Digital Sky Surveys field, with the footprint of one particular plate overlaid, and different symbols showing what objects have spectra?

I admittedly have several such "wouldn't-it-be-loverly" thoughts a week. But this seemed useful, beyond the "neato" factor. This kind of information is not immediately accessible on SkyServer--in fact, you need to a little SQL querying to get it, which is not the easiest thing in the world. This also might be a cool thing to distribute with old plates.

So, I built a little python tool that does this. Basically, it calls a routine that retrieves a square jpg image of the Sloan sky that has all the hard work done to it already. This means it takes just a few seconds to make.

The output looks like this--not bad for a couple hours of work. The only downside is that the images are super low-res (this is limited by the webpage I scrape the jpgs from). Originally, the plan was to download 3-band FITS images and stack them using aplpy, but that hit a couple weird snags1 and I moved to the current method, since I had already written code for it for a different project.

There's also another aspect of this code that I'll describe in a later post. Frankly, it's interactive (jazz hands) and pretty sweet.

1 - This is totally something I want to fix, or at least write a function that gets a high-res version. I have some code written already, that uses montage-wrapper, but there are weird perspective issues. Another improvement I'd be interested in making is to allow someone to visit a webpage, punch in a plate number, and receive a figure. Since there are literally thousands of plates, it would be nice to not have to store all the images. If anyone feels like taking (either of) these on, I accept pull requests!