There has been a recent case where an observer fell asleep during observing at the night of the night and only woke-up after sunrise with the telescope mirror and dome still open. To avoid this an auto closing system is being developed which closes the telescope at sunrise after a set of warnings are issued on the TCS. A command will be included that allows to keep the telescope open (e.g., to do calibrations of NIR observations) up to a maximum of 60 min. It will only be possible to give this command from the control room.
In general, this system will only be active if the telescope dome is open at the time of sunrise, where the process will continue until the telescope is closed manually, or is automatically closed. If the dome is closed at sunrise this process will not be initiated. When closed, the dome can be opened at any time as is the case now. Preliminary tests of this system have been made.