MDM Observatory 2.4m Telescope Observing Report for 2021 May 16 Observer(s): Melso/Sitaram Institution(s): Columbia University Instrument: CHaS Worked for 4 hours (all night) Conditions were Photometric most of the night. No equipment or software problems were encountered. Seeing and Weather: Beg: Clear, Winds Calm Mid: Clear, Winds Calm End: Clear, Winds Calm Observing Summary: We were able to get on-sky after rebuilding CHaS' optical path. Performed lamp calibrations and observations of multiple nebulae. The guider software MaximDL was not working since the beginning of the night. The software is frozen and we were unable to terminate the program using the task manager or command line. We decided not to prioritize guiding and didn't try to restart the computer. ------------------------------ Submitted on 2021 May 17 [4:33:40]