ESO Faint Object Spectrograph and Camera
Portrait of an Observing Run
Observations and After

Daily schedule Calibration observations
Official observing time
After observations
The Daily Schedule
16.00 Hr (Local Time) Introduction to the telescope/control room on the first afternoon
16.00 Hr (Local Time) Start of dome/internal calibration observations every day
Sunset Start of twilight sky calibration observations
End of nautical twilight (sun at -12 deg) Can start observing standard stars and other bright targets
End of astronomical twilight (sun at -18 deg) Official start of observing night
00.00 - 02.00 Hr (Local Time) Midnight snack time at the canteen
Beginning of  astronomical twilight (-18 deg) Official end of observing night
16.00 Hr (Local Time)   till   Sunrise Telescope building accessible to the observer
16.00 Hr (Local Time)   till   Sunrise Car #137 at the observer's disposal

Note: Afternoon activities will be advanced by 30 minutes during winter to compensate for the earlier sunset

Visit to the Telescope/Dome
During the first afternoon, about 30 minutes before the start of calibration observations the observer will, if so desired, be taken on a brief tour of the telescope building including the observing floor and the cat-walk surrounding the dome.

The Control Room
Following the telescope tour, the observer will be given an introduction to the control room. Information on some of the more often used Control Room facilities (i.e. used by the observer) may be found here. These include computing facilities for  scheduling observations, data reduction and back-up, internet access, personal lap-top connections, a lounge for relaxing and some appliances for making/storing snacks.

Midnight Snack
The canteen is open for snacks between midnight and 2.00 AM every night. During this period observers may schedule a long observation and use the time to visit the canteen. Alternatively, observers can order a packed snack during lunch and collect the same after dinner and bring it along with them to the telescope.

Telescope/Control Room Access
Observers can only work in the control room between 16.00 hr and end of observations in the morning. The control room will be used by several of the support staff during the day as they go about making the telescope ready for the next night's observation.  We strongly discourage requests from observers to access the telescope/control room during the day and in the absence of a compelling need they will be turned down. It may be noted that the visitor accounts on the computers in the control room can be accessed from the general user room in the main office building below the hotel.

A car (currently #137) will be at the disposal of the observer between 16.00 hr and end of observations in the morning for moving between the hotel and telescope. The car may be picked up at 16.00 hr from its designated parking place just before the 300 series dormitories (above and behind the hotel). The key will always be in the ignition. Note: The same car is used by the day crew; thus the car has to be left in the designated space after the end of observations. Remember not to remove the key from the ignition.

Calibration Observations

Typically the afternoon calibration session will start by 16.15 hr (Local Time). The observer will be assisted by the support astronomer and/or  the telescope operator and the observer's role is essentially limited to deciding the type and sequence of the observations. In general, observers are expected to have a calibration sequence requiring not more than 2 hours on any single  day. An adequate sequence typically lasts about 45-90 minutes;  trying to cover all possible contingencies is not necessary and is discouraged. The instrument is stable across days on end and one can obtain a calibration frame of an unforeseen configuration the next day.

Twilight calibration exposures may be started around sunset  :  narrow band and spectroscopic flat-fields may need to be started even when the sun is visible above the horizon while one has to wait 5-10 minutes after sunset for broad band flats.  One usually has about 30 minutes for twilight observations.

One can save some time by focussing the telescope when the sky is still too bright for regular observations and even observing standard stars (especially spectrophotometric standards) before the end of nautical twilight.

Twilight calibrations may also be obtained at the end of the night but observers are requested to keep this to a minimum so as to allow the telescope operator to finish his duties at the stipulated time.

We do not entertain requests for calibration observations during the morning. The only exception is one sequence of long exposure dark current frames which may be left running unattended at the end of the night after the telescope has been parked and the dome lights switched off. Please note that the engineering staff start work in the dome at 8.00 AM and so if the darks are not completed by then there is the possibility of light contamination.

If for whatever reason these calibrations could not be executed during a run every effort shall be made to carry out the same on subsequent nights in service mode before any change in instrumental configuration and the data will be passed on to the observer..... but this is not guaranteed. In general the instrument is quite stable and calibration frames taken within a few days will be adequate. Note  :  In the ultimate reckoning it is the observer's responsibility to ensure he/she has all the required calibration before leaving the mountain.

Official Observing Time

The officially allocated observing night is the time when the Sun is more than 18 degrees below the horizon. Any fractional night allocation of telescope night will refer to the fraction of this period. Similarly only the time lost during this period (either due to technical problems or due to weather) will be counted in the official statistics compiled for each night.

It is emphasized that any time lost during the afternoon or twilight does not count towards telescope down time.

After the Observations
Data Tape
The observer's copy of the night's data is stored on a DAT tape as FITS files (DDS 3; using theUnix command dd with block size = 2880). This is left on the observer's table the following morning. This tape may be picked up when he/she returns for calibration observations during the afternoon. The data tape from the final night of the run will be collected by the support astronomer from the Control Room and handed over to the observer (in the hotel area) before his/her departure from La Silla. If required, observers will be provided with DATs or CDs for making their own back-up of raw images as well as of the results of analysis they may have carried out during the run.

Instructions for burning CDs are available here. Please note that CD burning and verification is solely the responsibility of the observer, and in particular we do not accept any liability nor do we make replacement copies.

Night Reports, Problem Reports, Requests
The observer should submit a report of every night's observation before retiring in the morning and the telescope operator will assist him/her in this matter. This consists of a brief comment summarising the observations followed by a report of problems and the consequent time lost, if any. This is very essential for efficient operation of the telescope as the day-crew will try and solve the problems reported in time for the next night's observations. This is also the place to put in any requests for the day-crew (instrumental set-up modification, special data back-up requests etc)

End of Mission Report
The observer is expected to submit a detailed end-of-mission report evaluating all aspects of the observing run - observing efficacy, facilities, support, improvements and  (why not) appreciation of the team's efforts if warranted! This is an important feed-back from the user community which will help us in improving the efficiency the services provided. We encourage observers to submit this before leaving La Silla but it can also be done on the La Silla Home Page  (clickon the End of Mission Report link under  Observing and Operations) after returning to their home institutes.

Send comments to : ls-spectro

Last modified: Wed Jan 16 04:12:17 CLST 2002 

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