At Least Two Weeks Before Your Observing Run

  • To schedule a remote session, please follow the instructions on the remote observing page.  If you wish to observe remotely, you must have prior on-site observing experience.  If you have any questions about remote access, please contact our Data Scientist, Jeremy Jones (This email address is being protected from spambots. You need JavaScript enabled to view it.).  Software and operations are evolving at CHARA, so if you have not observed in some time, please contact Chris Farrington (This email address is being protected from spambots. You need JavaScript enabled to view it.) to find out about recent operational changes.
  • For NOAO observers, please contact our Visitor Support Scientist, Gail Schaefer (This email address is being protected from spambots. You need JavaScript enabled to view it.) for help with preparing the observing plan.


Sending Your Setup Request to the CHARA Team

In order to streamline nightly operations, observers should send their configuration requests to This email address is being protected from spambots. You need JavaScript enabled to view it. at least two days prior to the beginning of your scheduled observing time. This request is sent to both the day-time and night-time staff. It is used to align the lab during the day and to set the configuration and slew to the first target at the start of the night. Please include the observing date, PI name, and program ID in the subject heading. The following information should be included directly in the text of the email:

  • Date of program
  • PI and program ID
  • Beam combiner(s)
  • Telescopes in first configuration and any changes during the night
  • Beam order (if you have a preference - see explanation)
  • PoP combination to start.  
  • Filter for CLASSIC or CLIMB: K', H, J
  • Spectral Mode for MIRCX: Prism50, Prism102, or Grism190
  • First target or check star. Please specify if the first target is an alignment star, fringe finder, calibrator, or object.
  • Any special requirements you might have (LDCs, CLIMB for fringe finding/tracking, non-standard AO beam splitter).
  • For MIRC-X, if your first target does not have 6T delay, please specify which telescopes you want to be in delay at the start and whether you want light on all 6 telescopes.
  • Communication with the array operators is currently done through the night-time-operations channel of the CHARA discord server. Please contact Chris Farrington or Jeremy Jones if you need an invitation to Discord. Skype can be used as a backup.

If you have made arrangements to have the array operator assist you with collecting the observations (e.g., if you are unable to be on the mountain and don't have access to a Remote Observing Center), then please include a detailed schedule for the night. This can be sent as a text file, pdf file, or excel spreadsheet and should include the following information:

  • UT range and baseline/POP configuration for each target
  • List of science target and calibrators (HD number, RA, DEC, Vmag, Kmag, diameter)
  • Calibration strategies, instrument settings, etc.


On the Night of Observation

Please arrive in the control room or the remote observing center around sunset. The Array Operator can provide an update on the status of the array and current conditions. In the case of inclement weather, the Array Operator will inform the observers whether to go on stand-by or to cancel the night. The work schedule for the Array Operators is posted in the Observing Schedule. The operator will begin opening the telescopes around 6 degree twilight, and science observations usually begin around 12 degree twilight.


Links for Detailed Observing Procedures