General Information

Paranal Science Operations (PSO) is the department of the European Southern Observatory responsible for the scientific operation of the telescopes at the Paranal Observatory site. These facilities include:

• The four Unit Telescopes (UTs) of the Very Large Telescope (VLT).
• The Very Large Telescope Interferometer (VLTI), combining the light from either the UTs or the Auxiliary Telescopes (ATs).
• The VLT Survey Telescope (VST).
• The Visible and Infrared Survey Telescope for Astronomy (VISTA).
• The future Extremely Large Telescope (ELT).

Watch live summit webcams and monitor current atmospheric conditions using the Astronomical Site Monitor (ASM).

Please see the LPO news page for observatory news.

If you are interested in joining PSO, please explore our information on career prospects and working conditions. You can also visit our alumni page to learn where former department members have continued their careers.

Information for Observers

The Science Operations pages provide information and support throughout the complete lifecycle of an observing programme, from proposal preparation to data reduction and archive access.

Preparing your proposals for observing time and your observations

• Call for Proposals: CfP 
• Target of Opportunity Proposals
• Director discretionary time
• Exposure Time Calculators: ETC 
• Tools to compute ephemerides, visiblity, airmass, etc.

Visitor Mode Observations (VM)

• Before your observing run, please familiarize yourself with the relevant instrument documentation and observation preparation tools (p2). 
• Detailed practical information for visiting astronomers is available on the  Visitor Information page. 

Designated Visitor Mode Observations (dVM)

• Prepare the observing material following the phase2 guidelines.
• At least 10 days before your run, complete and validate all observing material in p2, including the Readme file. 
• Additional information is available on the Designated Visitor Information page.

Service Mode Observation (SM)

• Information on observation preparation, submission, scheduling, execution, and data delivery is available through the USD Phase 2 page.

After the observations...

• Observer feedback is important for operational improvement.  Following your observing run, you will receive a link to a web-based feedback survey. We greatly appreciate your participation.
• Data access: Science Archive

Targets of Opportunity (ToO) and Director Discretionary Time (DDT)

• DDT Instructions: Information for submitting DDT proposals.
• RRM trigger Instructions for triggering Rapid Response Mode Observations.
• RRM Status: Log of current instrument status and RRM triggers.
• ToO Policies: Policies governing the execution of ToO observations.

Other policies

• VLT/VLTI Science Operations Policy: approved by the ESO Council.
• LGSF Policies: policies governing operational constraints and potential conflicts related to laser guide star observations.

Technical Information

Paranal:

• Information about the site position, general weather information, seismicity
• Weather, past, present and forecasted
• Forecasts for advanced users
• Ambient condition database: access the database for any past night at ESO sites
• Ambient conditions of the last 24 hours

Telescopes

• VLT Unit Telescopes 
• VLTI Auxiliary Telescopes
• VST, the VLT Survey Telescope
  
• VISTA, the Visible and Infrared Survey Telescope for Astronomy
  
• DIMM, the seeing monitor
• MASCOT, the all-sky camera

Instruments

• Instrumentation overview