sci23066 — Announcement

Gemini South Shutdown Completed

December 11, 2023

The Gemini South shutdown was successfully completed on 24 November. It spanned nearly eight weeks, and the team achieved significant milestones:

  • Helium Lines Replacement: The Cassegrain wrap now boasts new helium lines. The replacement was important as both the original helium lines had failed, and the spare lines were displaying signs of aging.
  • Acquisition and Guiding (A&G) Unit Maintenance: The peripheral wavefront sensors (PWFS) of the A&G unit underwent thorough maintenance. The initial night of scientific observations revealed a remarkable improvement. The noise that was present before the maintenance is now absent, ensuring smoother and faster acquisition of guide stars.
  • Primary Mirror (M1) Recoating: M1 received a full recoating, seven years since the last coating. The reflectivity had significantly decreased, and with the new coating we have achieved close to a 15% higher reflectivity compared to pre-coating values.

With heartfelt appreciation, we extend our gratitude to the remarkable NOIRLab team, comprising individuals from Gemini South, Gemini North, Tucson, Cerro Tololo, and the SOAR Telescope, who wholeheartedly supported the local Gemini South team. The successful completion of these tasks stands as a testament to the collective efforts and diverse talents of everyone involved in this monumental endeavor. A big thank you resonates to each contributor for their invaluable contributions.

Gemini South is now back in regular science operations and has been taking science data every night since then. Note that we are still progressing with returning to a more 'normal' mode of operations after the cybersecurity incident. The lessons learned from the incident have shown us that this new ‘normal’ will be similar to before but with some constraints.