Skip to main content

Archive - FAQ (Getting Data - General) - Knowledgebase / Archive / FAQ - ESO Operations Helpdesk

Archive - FAQ (Getting Data - General)

Authors list

ESO Archive Frequently Asked Questions

Getting Data (General)

  • Are all data from ESO Archive available worldwide?

As a rule, science data in ESO Archive are available to users worldwide as soon as data proprietary period has expired (typically: one year), while calibration files are available immediately. A limited number of special programmes may have non-standard proprietary periods or be restricted to users from ESO Member States.

  • How is the proprietary period of data regulated?

Starting as of Period 91 (and covering also observations carried over to period 91 and subsequent), the proprietary period of all science and acquisition files is counted from the moment the files can be accessed and downloaded from the ESO Science Archive, i.e. both data and metadata have arrived in the ESO Science Archive in Garching. The release date of any affected file is set to the date of that event (successful reception) plus "the proprietary period" (typically one year), and the proprietary countdown begins.

The above applies to both Visitor and Service Mode data, as the Archive is the only official channel for accessing the data.

No PI or PI delegate action affects the run of the proprietary period.

Calibration files are not subject to any proprietary period, and are immediately accessible to all users.

Processed data have their proprietary period associated with their parent raw files.

Related link: ESO data access policy

  • How can I monitor the progress of my request?

For requests submitted using Instant Download or USB Disk, they can be tracked by accessing the ESO Archive Requests facility at

For Download Requests performed via the ESO Science Portal and other query interfaces, progress of a request of data can be visualized at the link[random string]

  • Will I be notified once my data become available in the Archive?

Your data are available in the archive within 10 minutes after observations hence no notification is sent to you either than browsing the archive. A month before the first file of your programme becomes publicly available in the ESO Science Archive, you will receive a reminder email.

  • I have problems untarring .tar files.

While untarring a file, a colon ":" in a filename may be misinterpreted by your system.
To untar such a file, you may then use the --force-local option.
Example: tar -xvf HARPS.2019-09-01T01:21:50.518.tar --force-local

Alternatively, you may add a "./" before the filename.
Example : tar -xvf ./

  • How can I display the 9 Gb fits files of the stacked UltraVISTA images?

You must have a 64 bit OS to display the images. It will work right away in ds9 if your machine has at least 9 GByte of RAM. If not, you can choose to cut the image and open only the section you are interested in, by making use the cut-out service offered via the Science Portal.

Alternatively, you can use imcopy in IRAF, the Cutout2D utility in Python (from astropy.nddata.utils import Cutout2D), or the stand-alone utility fitscopy that comes with CFITSIO. Compiling fitscopy is usually as simple as:
 make fitscopy
You can then copy out a subsection e.g. as
fitscopy 'filename.fits[6317:42736,7063:37182]' filename.trim.fits This particular subsection would be about 4 Gbyte (and requires about 4 Gbyte RAM to make); you can of course try something smaller. The format of the subsection is x1:x2,y1:y2 (just like in IRAF).

  • How can I make use of the Phase 3 1d spectra I just downloaded?

See the spectroscopic data products page.