ETC (Exposure Time Calculator)

The Spanish WSO-UV Team at the Universidad Complutense de Madrid has developed an Exposure Time Calculator (ETC) for ISSIS. The ETC allows the astronomers to evaluate the obseving time needed for a given scientific observation. ISSIS ETC allows computing the exposure time needed to reach an specific signal-to-noise ratio (S/N) for a given observation, or viceversa. ISSIS ETC is available here. The user's manual can be downloaded as a PDF.

Frontend of our ETC tool.


Large sky surveys are providing a huge amount of information for studies of the interstellar medium, the galactic structure or the cosmic web. Setting into a common frame information coming from different wavelengths, over large fields of view, is needed for this kind of research. GALEX is the only nearly all-sky survey at ultraviolet wavelengths and contains fundamental information for all types of studies. GALEX field of view is circular embedded in a squared matrix of 3840 x 3840 pixels. This fact makes it hard to get GALEX images properly overlapped with the existing astronomical tools such as Aladin or Montage. We developed our own software for this purpose. In this website, the software is made available to the community.


The Galex Educational Reader (GalexER) is a simple web interface to access the GALEX files providing only a specific data like UV channel (far or near), right ascension, declination, observation date, observation time and exposure time. The GalexER was developed to search in the Galex database for files within a range of parameters in a simple way. It includes a small database. To be used, it is required an user ID/PASSWD. Ask us for the password by e-mail.

The GalexER application has not its own FITS files database. It only redirects to the original GALEX archive in the Mikulski Archive for Space Telescopes.
Visit the complete form of Galexer in this link.