ESO FAQ

Australia entered into a 10 year Strategic Partnership with ESO in July 2017. In order to help get our community “up to speed” in time for the first ESO Call for Proposals, Dr Devika Kamath from the AAO’s International Telescopes Support Office compiled a list of “Frequently Asked Questions”, with input from ESO’s User Support Department. This information does not replace or override ESO’s extensive on-line documentation, but does provide a handy “jumping off point” to hopefully get you quickly to the information you require. Please contact us if you spot any errors or omissions in the information provided. 

I HAVE NEVER USED THE ESO FACILITIES BEFORE. WHERE CAN I START?

All information on how to observe with ESO telescopes is provided here. The link provides all the required information on how to prepare proposals for ESO’s telescopes, information for visiting astronomers as well as information on observing programmes, scheduling, Target of Opportunity (ToO) proposals, Large Programmes and Director’s Discretionary Time (DDT) Requests. All ESO data can be accessed via the ESO Science Archive Facility.

DO I NEED TO HAVE AN ESO USER PORTAL ACCOUNT?

Yes! An ESO User Portal account is essential for accessing all ESO services and observations. This includes submission of proposals to ESO (using the p1 web-based submission system), accessing the OPC results, submitting Phase 2 observing material, as well as accessing the raw and reduced ESO data and advanced data products (catalogs). Please use the ESO User Portal to create an ESO user account, which should include not just your affiliation but also gender, year of PhD, ORCID, and keywords identifying your expertise. More information on the ESO User Portal can be found on the ESO User Portal FAQ page.

WHERE CAN I FIND INFORMATION ON THE PHASE 1 CALL FOR PROPOSALS?

Proposals for observations at the ESO telescopes are invited twice a year. A copy of the Period 106 (Oct 2020 – Mar 2021) Call for proposals can be found here. A direct link to the call for proposals for the La Silla Paranal instruments and facilities can be found here. If you are an experienced user, and just want a précis of what’s new in the coming Period, you can visit AAL’s ESO Forum How to Apply page.

WHAT DOES PHASE 1, PHASE 2 AND PHASE 3 MEAN?

Phase 1 includes processes from proposal preparation to scheduling to the final communication to the PI.

Phase 2 includes the observation preparation for ESO telescopes and follow-up of their execution. Service Mode observations are prepared prior to the observing period start (typically deadlines are in the beginning of February and beginning of August). After the Phase 2 observation material is validated and approved, the Service Mode observations are carried out by ESO staff within the period for which the observing programme is scheduled. Data quality is assessed by the observers, who classify the observations accordingly as completed or to be repeated. All data are transferred in near-real time to the ESO archive and users have access to follow-up the status of their observations as well as to download their data. Pipeline-reduced science data are also made available for most ESO instruments. Visitor Mode observation preparation is typically done shortly before the observing run starts and the observers get support from the observatory staff on the mountain.

Phase 3 consists of preparation, validation and ingestion of science data products for storage in the ESO science archive facility, and subsequent data publication to the scientific community at large. PIs of successful Large Programmes and Public Surveys are committed to carrying out Phase 3. Other contributions are welcome.

DOES ESO PROVIDE EXPOSURE TIME CALCULATORS (ETCS)?

Yes, ESO provides ETCs for most instruments. ESO’s main ETC page can be found here. Note: Users are required to mention the seeing (as defined by a Turbulence Category) used while calculating the exposure times in the Phase 1, preferably in the ‘Technical Justification’ section of the proposal.

HOW DO I PREPARE MY PHASE 2?

Information on preparation for Phase 2 of observing with ESO can be found here. All Phase 2 observing material for Paranal instruments must be prepared using the web-based application p2, while for La Silla observers Phase 2 observing material must be prepared using the similar web-based application p2ls. First-time users are encouraged to make use of the p2demo environment, which can also be used at the Phase 1 stage (i.e., proposal preparation/submission) to calculate the observing overheads. Finding charts for most instruments can be generated automatically within the p2 tool using the p2fc application.

DOES ESO PROVIDE SERVICE MODE OBSERVATIONS?

Yes, ESO observations can be requested in Service Mode. A relatively recent overview of observing modes at ESO telescopes can be found in Marteau et al. (2016), SPIE. Overviews of Service Mode operations and performance metrics can be found in Primas et al. 2014, ESO MessengerPrimas et al. 2016, SPIE and Sterzik et al., 2016, SPIE. Users of Service Mode are usually curious to know how and when their observations would be scheduled. The current algorithms used for scheduling Service Mode observations on Paranal are described in Sec. 2.5 of the old P2PP3 user manual and in this presentation. This algorithm has evolved from the requirements for preparing and scheduling survey observations that is described in Bierwirth et al. 2010, SPIE, and it includes the more general principles described in an older article by Silva 2001, ESO Messenger.

WHAT IS THE DIFFERENCE BETWEEN SERVICE MODE AND VISITOR MODE?

The main difference is that observations in Visitor Mode are scheduled on a specific night or set of nights, while Service Mode observations from many different programmes are scheduled over a longer period of time. This allows flexible scheduling and observations of the programmes within requested constraints depending on current observing conditions. In Service Mode top priority programmes are executed when their observing requirements are met, but if the conditions change, the observer can quickly select another programme that fits well the conditions from the Service Mode pool. Visitor mode offers more certainty about when observations will be taken, as well as real-time flexibility in how observations are carried out depending on the prevailing conditions and the incoming data. For more discussion of the pros and cons of Service Mode vs Visitor Mode, see this presentation from the 2018 La Silla Paranal Users Workshop.

WHAT ARE THE DIFFERENT ‘OBSERVING CONDITIONS’ RELEVANT FOR ESO PROPOSALS?

An overview of the Observing Conditions relevant to ESO proposals can be found here.
 

DOES ESO SUGGEST ANY TIPS AND TRICKS FOR OBSERVERS?

A lot of useful tips for users can be found in the various presentations at the 2018 La Silla Paranal Users Workshop, where copies of presentations from ESO staff, and recordings of their presentations can be viewed.

HOW CAN I MAKE BEST USE OF BRIGHT TIME?

The following articles explain how to make most effective use of bright time for your observations:
Patat, F., 2004, Messenger: “Observing During Bright Time: Tips and Tricks
Patat, F., 2004, Messenger: “Night sky brightness during sunspot maximum at Paranal
Patat, F., 2008, A&A, 481, 575: “The dancing sky: 6 years of night-sky observations at Cerro Paranal

IS IT POSSIBLE TO MONITOR THE STATUS OF A SERVICE MODE PROGRAMME?

Yes, you are encouraged to monitor the status of your SM observations. This can be done from the Phase 2 section after logging in to your ESO User Portal account, using the “Check the status of your observing runs” link. This will bring up a list of all programmes on which you are the PI, or have been delegated access to. Clicking on any Run ID will show a breakdown of each OB and their execution status. From here you can also subscribe to receive night reports via e-mail each time an observation for their programme is executed.

WHERE CAN I FIND INFORMATION ON THE PROCEDURES CURRENTLY IN PLACE AT ESO FOR PROPOSAL SELECTION AND TELESCOPE TIME ALLOCATION?

Information on selecting and scheduling observing programmes at ESO can be found in Patat & Hussain, 2013 as well as in the article on “Growth of Observing Programmes at ESO” by Patat & Hussain, 2012, ESO Messenger. A deeper insight into the OPC process may be gleaned from watching ESOcast 116. You should also familiarise yourself with the requirements for dual-anonynous peer review.

CAN A PI DELEGATE ACCESS TO THE PHASE 2 TASKS AS WELL AS DELEGATE PROPRIETARY DATA ACCESS RIGHTS TO A CO-I?

Yes. A PI can delegate the Phase 2 responsibility, as well as give proprietary data access rights to any Co-I listed on the proposal. This can be done from the Phase 2 section after logging in to the ESO User Portal.

DOES ESO PROVIDE REDUCED DATA?

A variety of processed data is available via the ESO Science Archive Facility. They are either generated by the community for specific programmes and science goals, or by ESO using standard data reduction procedures for the entire history of the most popular instrument modes. Extensive documentation is available for each data collection (ESO data releases and ESO data streams). Users should critically evaluate whether the available processed data are suitable for their science goals. As an alternative, ESO makes tools available to process raw data, through which users have full control over the reduction process.

The official ESO data access policy can be found here.

WHAT ARE THE RECOMMENDED WAYS TO REDUCE ESO DATA?

EsoReflex, (Freudling et al., 2013Ballester et al., 2011) is the recommended environment to reduce ESO data. It automatically organizes input files according to their category and runs the entire reduction chain at the push of a button. It supports break points in the reduction sequence to inspect and interact with intermediate and final products, and rerun the corresponding step if necessary. EsoRex, a command-line utility for running pipeline recipes, and Gasgano, a Java-based data file organiser, are also available. The list of available pipelines, and corresponding tutorials can be found here.

CAN I MONITOR THE ESO DATA QUALITY CONTROL?

The trending of the ESO instruments can be found here.

HOW CAN I ACCESS THE ESO DATA ARCHIVE?

Access to the ESO archive can be found here. In the archive one can get the Raw data (science, calibrations and acquisition) as well as the Processed data. Browsing the science archive does not require any login, but downloading data does require you to login with your User Portal account.

A more intuitive, visual interface to data availability on particular targets or patch of sky is available at the ESO Archive Science Portal.

CAN I APPLY FOR DIRECTOR'S DISCRETIONARY TIME (DDT)?

DDT proposals can be submitted at any time. Full details on the nature of DDT proposals and applying for DDT can be found in the ESO DDT page.

WHAT IS A SCIENCE VERIFICATION (SV) PROGRAMME?

Science Verification (SV) programmes are intended for verification of the performance and capability of a new instrument or mode. These are Service Mode observations and are ideally ‘demonstration’ proposals (preferably 2 to 5 hours). These proposals should be directly aimed at the new mode of the instrument offered. SV nights are advertised in the ‘Science Newsletter’. They are normally announced before the typical proposal deadlines and are timed to follow-up with the normal calls. Please refer to the ESO SV page for further details.

DOES ESO HAVE A NEWSLETTER?

ESO has a number of on-line and printed publications that provide the latest news from ESO. The monthly ESO Science Newsletter is aimed at the scientific community and provides information on the technical and operational news from ESO. To start receiving the ESO science Newsletter you will need to create an ESO User Portal account. ESO also has a quarterly journal presenting ESO’s activities to the public. This is called ‘The Messenger’. Click here for more information on ‘The Messenger’ and how to subscribe to the print version.

WHAT IS ESO TELBIB?

TELBIB is the ESO Telescope Bibliography.  Here, users can view and query for ESO publications, and reach the raw and processed data used in each publication.

HOW CAN I GET IMMEDIATE HELP WITH AN ESO QUERY?

Australian ESO users are encouraged to direct all queries for help in the first instance to [email protected]. Due to time-zone differences between Australia and ESO Headquarters in Garching/Santiago, urgent or relatively simple queries may be directed to [email protected] or (0419) 970834, and we will endeavour to provide an answer as quickly as we can.

ARE ESO DATA PROTECTED BY COPYRIGHT, AND HOW DO I ACKNOWLEDGE THEIR USE IN PUBLICATIONS?

When using ESO scientific data, please follow these guidelines. There are separate rules on the usage of ESO public images and videos.