La Silla Science Operations

La Silla Science Operations Department (LSO) is part of the La Silla Paranal Observatory and is in charge of the operations of the telescopes on La Silla. These telescopes are: the 3.5-m New Technology Telescope (NTT), 3.6-m Telescope, 2.2-m ESO/MPI Telescope.


Always carry your torch with you and flash it while walking during the night on La Silla. Be cautious, because cars are driven with very low illumination. If you did not find a torch in your room, please request one immediately at the Reception (phone 4192).

LSO News

  • 2009-Jul-29: See below the new transportation schedule for visiting astronomers, to be started in October 2009.
  • 2009-Feb-11: From the second week of July, 2009, observations will be carried out from a new control room located in the administration building.
  • 2009-Feb-11: A new page describing the way that operations will run after P83 (ie from October 2009) is available here.
  • 2008-Apr-22: A document that explains how to interface >visitor instruments with focal stations of La Silla telescopes is available here (2.8MB PDF format).
  • 2007-Mar-26: The dome of the 3.6m has been fully restored, and moves with nominal speed.
  • 2006-Oct-05: The dome of the 3.6m enters an extended period of corrective maintenance. Science operations at the 3.6m is temporarily suspended until further notice.
  • 2006-May-17: A Trio of Neptunes discovered with HARPS, see ESO PR 18/06
  • 2006-Jan-26: A 5.5 Mearth planet discovered with the 1.54m Danish telescope.

Information for Observers

In the La Silla Science Operation 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 LSO pages for the astronomers, which are described in more details hereafter. Also, some useful ESO pages (not belonging to LSO) can be accessible from the left sub-menus and are explained in this page.

Preparing your proposals for observing time and your observations

Visiting astronomer coming to La Silla

  • The presence of the Visiting Astronomer at LA SILLA before the start of the observations depends on the transportation schedule. As of Period 84 (October 01, 2009) ground transportation between the observatory and the airport in La Serena and vice versa will be available from Mondays to Fridays only. In general, the Visiting Astronomer will arrive 1 to 2 days before the start of observations, and may leave the site up to 1 to 2 days after the observations.
  • Before your observation run: you should familiarise yourself with the technical documentation (see below), and with P2PP. This Visitor Information page contains the info you will need. From that page, you will also find informations on the Data Reduction Facilities and e-mail at your disposal.


    Remember to prepare
    • a backup program in case of poor seeing, thin clouds or strong winds (usually implying targets with Dec <-25 deg),
    • the list of additional objects you want to observe in addition to your approved targets
    and to request their approval well in advance using this procedure

    NEW - Jul.2007 - requests have to be sent using the webform included in the updated procedure


  • Arriving on La Silla, you should also check out the practical information you should find in your room (or on this web page)

Before the Observations

The information in this section is incomplete. More details will be added asap

  • Contact your Support Astronomer
  • Fill out Request Forms

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.
  • ToO Policies: the rules governing the execution of ToO at the La Silla Paranal Observatory.

Technical Information

La Silla