FITS files - an introduction

Astronomers use a special file format for storing and sending astronomical data such as images and spectra. These are called Flexible Image Transport System or FITS files for short. These are not strictly image files as they contain much more information and so there are many ways to view a FITS files.

All LCO images are stored in a compressed FITS format which reduces the file size by a factor 3.5. The file extension '.fits.fz' shows that the files have been compressed. You need specialist software to view these files - more information on this is given on the astronomical imaging page. When you download data from the LCO archive, or from your own LCO account, it will be in .fits.fz format. However, if you have imaged an object with 3 filters (BVR) then you will have the option in your LCO account to download a colour image of your object. This is not perfect but gives a nice idea of what your object looks like in colour.