ESO Archive Frequently Asked Questions

How can I check the quality of science observations?


For Service Mode runs, the associated Night Log file is provided together with each science frame when it is requested from the Archive.
If you have a doubt on the quality of a science observation, please first check in the associated Night Log report which contains comments on any issues that could have happened during the observation (e.g. instrument problems), as well as the information about the ambient conditions for that night (seeing, transparency, etc.).

If the information you are looking for is not reported in the NightLog, then please feel free to contact us via