apo-wiki

Attending: Nancy Chanover (NMSU), Aleksandr Mosenkov (BYU), Russet McMillan (APO), Anne Verbiscer (UVa), Adam Kowalski (CU), Misty Bentz (GSU), Ben Williams (UW), Moire Prescott (NMSU), Joanne Hughes (Seattle U), Chip Kobulnicky (UWy), Michael Hayden (OU), Eric Bellm (UW), Sarah Tuttle (UW), Bill Ketzeback (APO), Gordon MacDonald (APO)

• Colorado - user or two wondering about status about data reduction for KOSMOS - is PyKOSMOS finished and ready for widespead use or using standard IRAF - spectra are tilted so much that need to use Marsh algorithm rather than Horn algorithm. Documentation currently lacking. NC takes action to chase this in collaboration with Sarah
• BYU - nothing to report
• Oklahoma - nothing to report
• UVa - nothing to report
• Wyoming - nothing to report - interest in repair of KOSMOS
• Georgia State - nothing to report
• NMSU - nothing to report
• Washington - nothing to report - echo Chip on KOSMOS repair
• JHU - nothing to report (by email)
• Seattle - nothing to report - comment on the KOSMOS reductions - we had a college of idaho student working with Holtz on mask MOS reduction - pretty stable/student resistant, publicly available but not on the wiki yet, she would be happy to share it - will put on wiki
• 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.

Highlight some of the items - APO hosting Open House this coming weekend. Giving public demos, tours, talks over 4 hour event. 3.5m telescope is performing as expected for this time of year; had a significant failure one of actuators on secondary froze when changing between 2 ports. Homing of mirror correct problem with no further issues; caught during poor weather so science no time lost. 0.5m working as expected; Dcam spare and Uvacam are available to users for Q4. KOSMOS. Report incorrectly stats that cold and stable; it is not it is warm and in parts. Increased dark current reported by users; last month concluded that becoming unusable for science. Didn't want to wait for December to do inspection, Upon taking it down, 4 thermal connections between LN2 cold strapping and cold block that cools CCD; 3 of them were broken; only 1 was providing cooling. Ordered new strapping material to do a repair. Delayed because had to come from Europe. Once arrived we did not have correct knowledge to repair; much more difficult than what we can do on site. Reached out to vendors, got quotes, cold head block and various pieces sent out to shop in Albq. Need to procure materials. Hoping by early next week the repairs will be completed and picked up, then vacuum cleaning baking out, preparing dewar for service. Hoping for end of next week for return to service.

Nothing new on ARCTIC. Echelle - working on steamlining reaction software for calculating IOL; discovered that DATE-OBS keyword was wrong (45 min in the future from when image was written) - then did some data mining; this occurred in late August 2024 but not caught until now. If time steps are important for your echelle observations - ARCES observers should take note and we can provide the detailed time offset for anyone for whom this is critical. Report by a user a few weeks ago that new Th Ar bulb replaced in July 2025 had some weak/missing Ar lines in blue orders. We replaced with a different spare - did this on Sep 29. On Sep 30 reports that the new bulb was slightly fainter than bulb a year ago. Reduction process is more efficient now. Users should also note this. Hollow cathode lamps - can no longer obtain Th metal filaments; increasingly hard to find on the shelf. We just purchased some supply so that we have spares - hope that each one will last a few years each. Becoming harder to find old style THAr lamps. Alternative source may need to be identified.

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?