Gemini Mirror Status: 16 March 2023

An update from the Gemini Observatory Director, Jen Lotz, on the status of the Gemini North primary mirror.

I am very pleased to report that the glass surrounding the chipped region of the Gemini North primary mirror is now repaired! Despite challenging weather conditions on Maunakea, Safran-REOSC was able to finish the grinding and polishing of the damaged regions of the primary mirror.  

The REOSC team members have performed their final birefringence tests, which help determine the optical properties of the material, and confirmed that the stress has been released. The Gemini/NOIRLab team has performed the initial inspections of their work and is very happy with the results.  

We still need to re-attach the replacement lateral pad, complete the mirror coating, reassemble the telescope, and perform a series of checkouts before returning to nighttime operations. 

Continuing updates will be posted on both the NOIRLab and Gemini websites.