Essential tasks of a SA during an on-duty night

5-7 days before your observers' run

• Send an email to your observers to introduce yourself, and ask them what their plans are for their run. This is particularly important for LRIS observers, as their masks need to be milled, installed, and tested before going to sky. Ask them for questions they might have.

• In the case of remote observers, make sure they install the observing software some days beforehand, so the software is tested properly, and there is enough time to fix potential problems. Make sure the observers test their connection, and that they are able to see all the VNCs before the day of the run. Make sure they have all the passwords they need.

• Agree on a time to meet during the afternoon on the day of their run for cals.

The day of the observing run: afternoon

• If it is a split night with one instrument at the cassegrain focus, and one instrument at the nasmyth focus (e.g. HIRES-1st half/LRIS-2nd half, HIRES-1st half/MOSFIRE-2nd half at Keck 1), make sure that you call/email the summit (summitlead@keck.hawaii.edu), and the OA in duty that night, so that the cassegrain instrument is released as selected instrument. This is EXTREMELY IMPORTANT for LRIS, that needs to be focused every day for each of the observing configurations that are going to be used during the night. This focus is mandatory and needs to be done during the afternoon. LRIS and MOSFIRE calibrations require dome flats, and can be done simultaneously during the afternoon to HIRES calibrations, that do not require dome flats. In the case of MOSFIRE, it is less critical if cals cannot be done in the afternoon, as the observers will have the morning to do them.

• Check the weather (http://mkwc.ifa.hawaii.edu/forecast/mko/trends/), and the outside cameras at the summit (http://mkwc.ifa.hawaii.edu/current/cams/). The observers will ask you about that first thing in the afternoon.

• Check the SIAS webpage to see if the instrument/telescope has been released (https://www2.keck.hawaii.edu/realpublic/inst/siastng/release/web/Sias/siasEh.php?host=mysqlserver&table=datebook). The internal version of the webpage contains the phone numbers of the SWOC (software on call), that might be useful in case of software problems during the night.

• When the instrument has been released, and/or when it’s the time to meet your observers, join the zoom meeting at Remote obs. 1 (808 881 3714) to talk to your observers, and log into the VNCs corresponding to the session of today’s run.

• If the observers are beginners, you will need to explain to them how the instrument works, and how to use it.

• Tell the observers to put their starlist in the /kroot/starlists/nameofobserver/ directory.

• The electronic log of the observations is available here (internal link): http://observinglogs

• Once the observers are sort of familiarize with the instrument and are taken cals, you can leave until sunset. Give them your phone number to reach you in case of problems or questions.

The day of the observing run: sunset

• Arrive 5-10 min before sunset to the zoom meeting so that you can talk briefly with the OA on duty of the situation at the summit (weather, telescope, etc.).

• At sunset, the OA will ask the observers to open the hatch/trap door of the instrument. The OA will put the different elements of the telescope in position for observation, check the pointing, and do a focus. The focus is done using the MIRA (https://www.spiedigitallibrary.org/conference-proceedings-of-spie/4848/1/Mira-a-case-study/10.1117/12.461305.short?SSO=1) routine for instruments with imaging option (e.g. MOSFIRE, LRIS at Keck 1), or AUTOFOC for the others (HIRES).

• Pay attention that all the settings of the telescope/instrument look good in FACSUM (https://keckobservatory.atlassian.net/l/c/aDcEX0rD ). For the case of MOSFIRE, the drive angle is important to be taken into account during the observation. Rotator mode needs to be always PA mode during the observations. You will be able to see in FACSUM in which pointing origin the instrument is set (https://keckobservatory.atlassian.net/l/c/n5gvvhsQ ). It is good to be aware of the stage of the different mechanisms of the telescope during normal observations, in case troubleshooting is needed.

• Once the observers are in their first target, make sure they are confident with the procedure of the observation before you leave them on their own.

• Their data will be available in KOA next day.