Paranal Science Operations

General Information

Paranal Science Operations (PSO) is the department of the La Silla Paranal Observatory that is in charge of the operation of the telescopes on Paranal. These telescopes are:

  • The four Unit Telescopes (UTs) forming the VLT.
  • The VLTI, which is the interferometric combination of either the UTs or the Auxiliary Telescopes (ATs).
  • The VST and VISTA survey telescopes.
  • And in the future: the ELT!

Watch live webcam pictures from the summit of Paranal. Go here for a real-time check of the atmospheric conditions on site.

If you are interested in working at Paranal, you are invited to inform yourself about the career prospects and working conditions in the PSO department. Also check out our alumni page to see where our previous department members are working now.


PSO News

  • September 18, 2020: First scientific data taken with UVES@UT1 and FORS@UT2. Please see the LPO news page.
  • August 28, 2020: Minimal science operations to be resumed at Paranal, foreseen starting date September 23. Please see the LPO news page for more details.  
  • March 24, 2020: Science operations at Paranal have been stopped due to the Covid pandemic. For regularly updated news given the Corona virus situation, please consult the LPO news page.
  • April 2019: Visiting astronomers are asked to prepare their observations on their own laptop, via the p2 tool and the associated instrument specific tools. Upon request a Linux desktop can be provided to help with the observation preparation. 
  • October 2017: Users of designated visitor mode programs will be able to view from their computer at home the relevant operation panel in the Paranal control room, via the Paranal Observatory Eavesdropping Mode (POEM). Access credentials will be provided by the mountain staff at the beginning of the run. 
    • POEM is also available for co-Is that want to join visiting astronomers on the mountain remotely.
  • April 2017: As of April 3, visitors at Paranal are asked to prepare their observations using the new web-based tool p2 that replaces p2pp3. This includes designated visitor mode. Main changes with respect to p2pp3 include:
    • OBs are created using a web browser without the need for installation of a dedicated software.   
    • Any OB created through p2 will be directly recorded in ESO’s database and hence become available in real-time at the telescope console in the Paranal Control Room [i.e. no need to export OBs and/or transfer OBs]
  • September 2013: As mentioned in the CfP for P93 (section 5.1.2), ESO reserves the right to allocate time in Designated Visitor Mode (dVM) on the VLT(I) telescopes instead of in regular Visitor Mode. PIs of such dVM runs are informed at the time of the web letters that instructions for the relevant procedures are described under the section  “Information for Observers” at the URL: (this page).
  • January 2013: In our commitment to continuously improve the services provided to the community of ESO users, our operations model has recently undergone a reorganization of the day- and night- time tasks. The implementation of the related changes has started in January of 2013 and full deployment is expected to last until mid-2013. These changes aim at enhancing: 
    • the quality of the daytime support, in particular towards visiting astronomers (the nighttime support astronomer will most of the time also be available to help with the preparation of the science programs), and
    • the quality of the instrument support (documentation, science product and related calibration/reduction).

Information for Observers

In the SciOps pages, you should find all the information you need for your observations from the time you have an idea of observations until when you finish processing your data. The menu on the left contains the list of the PSO pages for the astronomers, which are described in more details hereafter. Also, some useful ESO pages (not belonging to PSO) can be accessible from the left sub-menus.

  • Preparing your proposals for observing time and your observations

  • Visiting astronomer coming to Paranal

    • Before your observation run: familiarize yourself with the technical documentation and with p2
    • This Visitor Information page contains the info you will need. 
  • Designated Visitor Mode Observations (dVM)

    • Although the preparation and execution of your dVM run are similar to that of a VM run, the preparation of the observing material should follow the phase2 guidelines.
    • At least 10 days before your run, please have your observation material prepared within p2, including the Readme file. 
    • This Designated Visitor Information page contains the info you will need.
  • Service Observation

  • After the observations...

  • Special cases - Targets of Opportunity and Director Discretionary time:

    • DDT Instructions: how to apply for Director Discretionary time.
    • RRM trigger instructions for triggering Rapid Response Mode Observations.
    • RRM Status: log of the instrument status and of the RRM triggers.
    • ToO Policies: the rules governing the execution of ToO at the La Silla Paranal Observatory.
  • Other policies

Technical Information