Visitor Mode Phase 2 Guidelines

This page provides information about Observation Block (OB) creation only for users assigned Visitor Mode time at ESO telescopes. Astronomers having obtained observing time in Service Mode should consult instead the links provided on this page.


Users should familiarize themselves with the appropriate instrument documentation, including ESO supported calibration plans, as well as with all the various logistic-related aspects available from the La Silla and Paranal webpages. Please consult as well the ESO Travel Guidelines for Astronomers on Mission to Chile.

All Paranal Visitor and designated Visitor Mode users are asked to prepare their observations using the web-based application p2.

For general definitions related to Phase 2 preparation, visitors should read the Phase 2 workflow page before arriving at Paranal.

Starting in October 2019 the web-based replacement for the ESO Phase 2 observing preparation tool P2PP named p2ls, has been released for operations at La Silla.  p2ls fully replaces P2PP for (designated) Visitor Mode observations of all instruments available at La Silla.  Note that p2ls is the La Silla “cousin” of the Paranal tool p2.

With the introduction of p2ls also the Phase 2 delegation becomes available for La Silla. Visitor Mode observers traveling to La Silla who are not PI of the observing run must obtain the delegation by the PI in order to be able to access the observing material. Please use the dedicated FAQs for details related to the Phase 2 delegation.

Targets and backup: Make sure you have enough targets for the whole night. In case you need more to fill the night, additional targets must be requested and approved in advance. Similarly, you should have a backup program in case the conditions do not permit your main program to be executed. In particular, keep in mind that strong wind often comes from the North, so backup targets to the South should be prepared. Additional targets, backup targets and change of set-up must be sought at least two weeks in advance of the observing run  using this procedure. Requests sent on shorter notice, in particular, less than 48 hours from the start of the run, may not be processed in time. In those cases, the corresponding data will not be accessible from the ESO Science Archive Facility until the request is approved.


OB Preparation on the Mountain

In principle, all Visitor Mode observers are requested to arrive on La Silla or Paranal 48 hours before the beginning of their observing run to allow time for OB preparation. Your Support Astronomer on the mountain will provide you with all needed guidance with the process of preparing your OBs. Visitor Mode observers with previous on-site observing experience may arrive on the mountain 24 hours before the beginning of their observing runs. Even in this latter case however, if you expect to need substantial assistance during the preparation of your observing run (for example because of using a new instrument), you should plan to arrive 48 hours in advance.


OB Preparation before arriving on the Mountain

ESO strongly encourages all users to prepare their OBs in advance to the arrival at the Paranal Observatory using the web tool p2.

Please notice that the scheduling containers can NOT BE USED for preparation of Visitor Mode OBs, because the Visitor Mode Observing Tool (vOT), used to execute the observations at the telescope on Paranal, will ignore them.

Please contact the ESO User Support Department if you need general assistance with p2, or if you have any questions on the preparation of your OBs not specifically related to your observing programme.


Whom To Contact For Help

Investigators assigned (designated) Visitor Mode time should contact the appropriate telescope team:

All investigators assigned Service Mode time should contact the ESO User Support Department in all matters regarding Phase 2.

If you are unsure of whether your allocated time is in Service or Visitor Mode, please contact the Observing Programmes Office (OPO).

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This page is valid for all instruments

Visitor Mode