Daytime and Nighttime Communication

Daytime staff and daytime OSs need to ensure that the telescope, instrument(s), and observatory tools are functioning as expected before the beginning of any night to minimize time loss due to unexpected faults.

Observers Arrival

Daytime OSs are charged with all telescope preparations and checkouts during the day. The daytime OS (day shift) schedule runs from 9 am - 9 pm summit time. The nighttime OS (late shift) schedule runs from 8 pm - 8 am the following morning, or wheneven observations are finished.

These sections describe afternoon checkout and fault reporting:

Staff that work on the summit depart for La Serena at 16:30 summit time Monday-Friday.

Night Logs

Details of work done during the day, such as software changes or mechanical work like as filter changes, mirror cleaning, and maintenance are published to OLE before the start of the night. Daytime staff publish the details before the end of day at the summit - 16:30 summit time.

More information about creating and writing night logs is found on the Nighttime Logging page.

Afternoon Checkout

Afternoon checkouts are important procedures to ensure that the telescopes and instruments are functional before the beginning of the night. The full procedures for the different afternoon or recommended daily checkouts are described on these pages:

  • AuxTel Daily Checkout

  • LATISS Calibrations

  • Comcam Calibrations

Reporting Faults

The JIRA project called Observing Operations (OBS) for all night time or telescope faults is specifically to raise issues that impair data being taken on sky. In case there is a telescope or instrument issue found during the day or during the afternoon checkout, the daystaff or observer must file a fault report and flag it to recive priority attention before the night begins. Observers are also encouraged to communicate directly with summit staff or Tucson support to address an issue quickly, but must file a fault report describing the issue and the recovery procedure, if known.

More details about filing a fault report can be found here.

This procedure was last modified Dec 06, 2025.