apo-wiki

Attending: Nancy Chanover (NMSU), Bill Ketzeback (APO), Russet McMillan (APO), Misty Bentz (GSU), Ben Williams (UW), Jamey Eriksen (APO), Sarah Tuttle (UW), John Wilson (UVa), Anne Verbiscer (UVa), Eric Nielsen (NMSU), Kevin Schlaufman (JHU), Joanne Hughes (Seattle U), Chip Kobulnicky (UWy)

• BYU -
• FGCU -
• Wyoming -
• Oklahoma -
• NAPG -
• Seattle -
• Georgia State -
• Washington - nothing to report (by email)
• Colorado -
• UVa -
• JHU -
• NMSU -

The detailed site report is included below, followed by additional information discussed during today's meeting.

3.5-m Telescope and Instruments Highlights, 8/01/2023 – 9/04/2023

1) Overview

It has been a very busy and exciting month at APO! Shutdown started in late July and culminated with the return to sky on 8/23. The mirror was successfully recoated at Lowell Discovery Telescope outside of Flagstaff. The team of Bill Ketzeback, Amanda Townsend, Riley DeColibus and Jamey Eriksen escorted the mirror to LDT, worked with the LDT team who cleaned, stripped and recoated the mirror in the LDT chamber, and then escorted the mirror back to APO.

In late August a visiting team from UVa for DSSI arrived at APO. In September we will host a visiting group from the Pacific Northwest, along with a group associated with the SDSS project for a software coding workshop.

2) Operations

3.5m Telescope:

The telescope returned to operations post-shutdown. The M3 rotation failure has been narrowed down to a failed high resolution encoder. A replacement has been ordered, a new mount is being fabricated and we anticipate being able to test the replacement encoder in 2 weeks. A plan is also being developed for an upgrade path for the M3 rotation system because of the obsolete parts in the system (the motors and motor encoders, which we have not been able to find spares for).

The telescope balance has been marginal after the removal of the LANL instrument. There is an occasional motion error during slews. So far no reports have been received about motion errors while tracking. Further refinements of telescope balance are ongoing.

Instruments:

- KOSMOS was warmed up during shutdown for a vacuum cycle with a getter recharge; the instrument is now cooled and operational.

- servicing of the ARCTIC diffuser rotator had to be postponed; it will be rescheduled for a later date.

- The Agile TEC controls failed. Princeton Instruments will no longer support the camera or controller hardware. Finding and ordering surplus equipment in an attempt to repair it has so far been unsuccessful.

- The ARCES inter-order light ratios (measure of scattered light in the instrument) are still good but are declining again in the warmer weather.

- The scattered light in the DIS red camera improved dramatically recently (attributed to a detector partial warm up) and the camera is considered to be very good. However, the blue camera is still considered sub-par.

0.5m Telescope: The filter wheel has failed. Attempts to repair it have so far been unsuccessful. A replacement filter wheel is being researched.

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There is no open time left in Q3.

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Open action items from previous meetings:

• Nancy: track down missing ARCTIC data reduction scripts for wiki. → OPEN XXX. Making progress on it this week.

New action items from this meeting:

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The next meeting will be on October 3 at 10:30 MDT.