apo-wiki

Attending: Nancy Chanover (NMSU), Bill Ketzeback (APO),

Misty Bentz (GSU), Aleksandr Mosenkov (BYU), Anne Verbiscer (UVa), Michael Hayden (OU), Kevin Schlaufman (JHU), Joanne Hughes (Seattle U), Moire Prescott (NMSU), Chip Kobulnicky (UWy), Ben Williams (UW)

• Colorado - nothing to report
• BYU - nothing to report
• Oklahoma - nothing to report
• UVa - nothing to report
• Wyoming - nothing to report
• Georgia State - nothing to report
• NMSU - nothing to report
• Washington - nothing to report
• JHU - nothing to report (by email)
• Seattle - nothing to report
• NAPG - no report

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

3.5-m Telescope and Instruments Highlights, 9/03/25 – 10/07/25

1) Overview

Monsoonal patterns continued for much of September, with unsettled weather affecting all but a small handful of nights this month. There were no visiting classes or PI instruments staying on site during the month. However, we did host daytime tours and had remote training sessions this past month. The 3.5m Night Operations team saw the departure of both Candace Gray and Mark Croom. We wish them both in their future adventures!

The site will be holding an open house event for the public (daytime only) on October 11. Science demonstrations, public talks, and tours of the telescopes will be the highlights of the four-hour event.

2) Operations

3.5m Telescope: Telescope is working as expected. Seasonal motion errors continue to occur infrequently. We anticipate that there will need to be some tuning of the axis drives by mid-November. This past Saturday, there was an occurrence where one of the three axial actuators for the secondary mirror did not move after an instrument/ port change. The operator corrected the problem by homing the secondary. The weather at the time was poor, so no time was lost.

0.5m Telescope: Telescope is working as expected. Dcam-spare and UVAcam are both available options for users.

KOSMOS: System is cold and stable. Increased dark current for long exposures has been confirmed. As discussed last month, the increase in dark current warranted opening the cryostat for inspection. Three of the four thermal connections from the liquid nitrogen can to the CCD cold block had failed, leaving only a single thin connection. Repairs were delayed by the shipping of material from Europe. We are currently searching for a vendor to assemble the parts, as we have not had success ourselves.

ARCTIC: The diffuser rotation mechanism is still unreliable even after a full servicing. The mechanism that moves the diffuser in and out of the optical path is still functional in the meantime. The rest of the instrument is cooled.

AGILE: The camera is non-operational; the thermoelectric cooler failed again. The camera is warm, and we do not plan further repair work with this camera. We are planning on decommissioning the camera. The agile instrument rotator is still not performing nominally, and we are troubleshooting it further to prepare for SoonerCam.

ARCES: While working on automating the interorder light reductions and archiving the data in a new database, we discovered that the FITS header KEYWORD for DATE-OBS was wrong by approximately 45 minutes in the future of when an image was written. Further data mining revealed this occurred during the summer/fall of 2024 when the ICC experienced power supply failure and hard drive troubles. It was not caught that the operating system service that syncs time to the site timeserver was not performing. The problem would have started on or after August 27, 2024. If time stamps are important for your echelle observations users should take note. A report from a user that the new ThAr bulb, replaced on July 22nd, had very weak lines or missing lines in the mid and blue orders prompted us to replace the bulb again on September 29. Wednesday, September 30th, observers then reported that the ThAr counts were around 3250 DN last year, but only 3100 DN counts tonight. This was the last new HCL we had on the shelf. It may be these two bulbs had lower pressure argon gas fill and therefore those are the lines missing. Comparison with line lists would need to be done to confirm. More bulbs are on order; however, Thorium-Argon lamps of the same type and manufacture as we were purchasing years ago are no longer available. We are buying up one European vendors back stock but we do not know if these will be of the same lamp strength as the old bulbs.

DIS: System is powered down and warm. Decommissioning plans have begun.

NICFPS: System is cooled and usable.

TripleSpec: System is cooled and usable.

APOLLO: The instrument is usable for laser ranging.

xxx update this xxx

The Q4 schedule is posted.

The ARCSAT Q4 schedule is posted.

• SoonerCam: xxx
• KOSMOS grisms (no change from last month): we are still awaiting a decision on the proposal we submitted for funds to support the purchase of three new grisms for KOSMOS.
• ASPEN: We recently learned that a proposal we submitted for funds to support the development of the new echelle spectrograph was not selected for funding. Work on the design of the new optical echelle spectrograph continues with the goal of completing the Preliminary Design Review in early spring 2026.
• Ocotillo: xxx

There are a number of events taking place over the next several months:

• We have 4 class groups coming APO in Q4. A fifth one will be moved to Q1. Please be patient with the site staff, who will be shorthanded during this time!
• We are in the midst of an in-person ASPEN team meeting at NMSU/APO this week.
• We are holding a public-facing Open House at APO on Saturday October 11. This will include site and telescope tours, activities, and talks at the Sunspot Astronomy and Visitor's Center. We look forward to welcoming the public back to the site; our last Open House was in March 2020.
• The ARC Board of Governors meeting is on November 4. Please submit all science highlights to Nancy no later than Monday October 27.
• The January 2026 AAS meeting will be in Phoenix, and we plan to have a booth. There was no motivation for a special session so we did not submit a proposal.

Open action items from previous meetings:

• Nancy: follow up with UWy KOSMOS user to determine severity of dark current issue.
• UC reps: remind your users to review the Q3 schedule and request OPEN time in September if they can make a good case for it.
• UC reps: poll your users about a Jan. 2026 splinter session at the AAS for APO science highlights and networking (or other ideas!).

New action items from this meeting:

• xxx

None.

The next meeting is currently scheduled for Tuesday November 4, 2025. This directly conflicts with the ARC Board meeting; shall we reschedule for one week later or cancel the November meeting and meet again in December?