# Stuck with SDSS data [closed]

I want to do project on astronomical dataset. Regarding that project, I try SDSS who give public dataset but it is quite complicated for me. I gone through public dataset and downloaded some .FITS file one is ~3.2mb and other one is ~3 GB but I don't know how to deal with this file and generate images or other files from .FITS files.

• The more specific you can be in your question asking in stackexchange, the better received the question. Once you have made some progress and can describe a more specific problem, you can consider asking a new question here. In that case you should add sufficient specific details. The question "I'm trying to open an unspecified, unnamed file and I can't; this is my research, what should I do?" is not ideal in SE. It's a very clear and understandable question for sure, but SE has certain requirements. You can take the tour or look at other questions. – uhoh Aug 13 '17 at 8:44
• One problem here is that you haven't described what you have tried so far. "I don't know how to deal with this file..." is not ideal. It would be much better if you had described what you've tried so far. For example, there is a Wikipedia page called FITS which straight-off inks to fits.gsfc.nasa.gov Asking a question here before even going to Wikipedia is not ideal. It happens sometimes, but next time make sure you've addressed "What have you tried so far?" so that nobody has to ask it. Welcome to stackexchange! – uhoh Aug 13 '17 at 8:51

The header of a FITS file is ASCII, and points you to further information. Calling head -n 1 example.fits directs you to "'Astronomy and Astrophysics', volume 376, page 359; bibcode: 2001A&A...376..359H".

A software to view FITS images is ds9 (yes, that makes it hard to google...). Alternatively, there's skycat. Both can be used to view and do basic analysis on FITS images.

For FITS binary tables, it is probably best to write your own analysis software. For a quick look, fv might do the job.

Accessing the data yourself

If you want to write your own software for analysis, take a look at either cfitsio, a C library for reading and writing FITS files, or pyfits, a python module which does the same and which seems to have merged with the astropy software package. The cfitsio page in the link above has links to documentation on both the cfitsio library and the FITS standard in general.

• I just installed Astropy.. Should I go with it? – Akshay Vilas Patil Aug 12 '17 at 14:53
• Why not? Unless, of course, you prefer C. For a quick look, ds9 is, of course, even simpler. But as this is a CS project, you'll be coding eventually anyway. – Alex Aug 12 '17 at 15:14
• I'm working with "astropy.io" library using "jupytar notebook", and it works fine for me now. Thanks for your suggestion which gives me some how to right direction. – Akshay Vilas Patil Sep 18 '17 at 15:12

You should go to the site https://fits.gsfc.nasa.gov/ where you can read about the FITS data format. This site also has utilities for examining and viewing the data. Most of your concerns about this data should be answered by the documentation on this web site.