ESO User Portal Frequently Asked Questions

Archive-Related Questions

Can I browse the science archive from the User Portal web page?
Logging into the User Portal is not required in order to browse the archive web interfaces, which are accessible by browsing to or clicking on the links in the "Archive Services" card on the main User Portal page (if you are already logged in to the User Portal).

Bulk data download or direct download of individual files through query forms under or through the ESO Archive Science Portal ( does not require being logged in for public data. If at the time you request proprietary data you are not already logged in you will be presented with the User Portal login page.

Browsing and downloading via programmatic access does not require authentication for public data (or, in fact, any interaction with the User Portal). For more details see