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 - Several CU users were wondering about the status of data reduction software for KOSMOS, and whether PyKOSMOS is considered finished and ready for widespread use or whether people should still be using standard IRAF routines. A user found that the spectra are tilted so much that they need to use the Marsh algorithm rather than the Horn algorithm in the reduction, and the PyKOSMOS documentation currently does not address this. Nancy and Sarah Tuttle took the action item to follow up with Jim Davenport on this and report back.
• BYU - nothing to report
• Oklahoma - nothing to report
• UVa - nothing to report
• Wyoming - nothing to report other than general interest in the timetable for the KOSMOS repair
• Georgia State - nothing to report
• NMSU - nothing to report
• Washington - nothing to report other than general interest in the timetable for the KOSMOS repair
• JHU - nothing to report (by email)
• Seattle - nothing to report regarding recent observations, but Joanne had a comment on the topic of KOSMOS data reduction. She and her collaborators had a College of Idaho student working with Jon Holtzman on software for slit mask/MOS data reduction. The software is pretty stable and is publicly available but it is not on the wiki yet. Joanne said she would be happy to share it and took the action item to put it on the 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: 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.

APO will be hosting an Open House this coming weekend, during which we will be giving public demos, tours, and talks over a 4-hour event.

The 3.5m telescope is performing as expected for this time of year. We had a failure of one of the actuators on the secondary mirror, which froze when changing between two ports. Homing of the mirror corrected the problem with no further issues; this was caught during poor weather so no science time was lost.

The 0.5m telescope is working as expected; Dcam-spare and UVAcam are available to users for Q4.

KOSMOS is warm and taken apart as a result of increased dark current reported by the users. At last month's Users Committee meeting we concluded that it was becoming unusable for science and the consensus was that we should not wait until December to do an inspection. Upon taking it offline it was discovered that of the four thermal connections between the LN2 cold strapping and the cold block that cools the CCD, three of them were broken; only one was providing cooling. We subsequently ordered new strapping material to do the repair; the material was delayed because it came from Europe. Once it arrived it became apparent that the repair would be more difficult than what we were comfortable doing on site. We contacted several vendors and got quotes, and ultimately the cold head block and various pieces were sent out to a shop in Albuquerque. They need to procure some materials to do the repair, but we are hoping that by early next week (week of Oct 13-17) the repairs will be completed. Then we will pick it up to return it to APO, do the vacuum baking out to prepare the dewar for service. Ideally we are hoping that it could return to service late in the week of Oct 13-17 but it could be later, depending on how quickly the shop can procure their needed materials and complete the repair. We will continue to update the scheduled KOSMOS users as we learn more about the timetable.

ARCES: While working on streamlining the software for calculating IOL it was discovered that the DATE-OBS keyword in the FITS headers was wrong (45 min in the future from when image was written). After some data mining we found that this occurred in late August 2024 but it was not caught until now. If time stamps 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. There was a report from a user a few weeks ago that the new ThAr bulb that was replaced in July 2025 had some weak/missing Ar lines in blue orders. We replaced it with a different spare on September 29 and the next day we learned that the new bulb was slightly fainter than bulb from a year ago so ARCES users should also note this. These hollow cathode lamps are no longer being made with Th metal filaments and it is increasingly hard to find spare lamps on the shelf. We just purchased a supply so that we have some spares and we hope that each one will last a few years. Given that it is becoming harder to find the old style ThAr lamps and alternative source may need to be identified.

ARCTIC, NICFPS, TripleSpec and APOLLO are all functioning nominally. DIS and Agile are still slated for decommissioning.

The Q4 schedule is posted. There is a fair amount of OPEN/DD01 time in late October (dark time, all B halves). We hope to use some of it to pay back KOSMOS users who had to give up their time but we're not committing to that until we know when KOSMOS will be returning. Some of the scheduled KOSMOS time may need to be allocated to other users, ideally from same institution. There is additional OPEN/DD01 time later in quarter, including a limited number of A halves or partial A halves. A huge thank you to Russet for doing such a great job with the challenging schedule for this quarter.

The ARCSAT Q4 schedule is posted. It is pretty full, but there is some time available later in the quarter. The two available instruments are UVa-cam (larger FOV) and Dcam-spare (smaller FOV and less oversampled). Dcam-spare did have some frost on the window after shutdown; it is gone now but we can still see signatures of it on the detector. They flat-field out but the frames look ugly when taking data.

• SoonerCam: Parts have been trickling in. So far we received the fiber and software developer's kit but we're still waiting on the fiber to coaxpress converters. We will dig into this after early November.
• 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. We are hosting an ASPEN team meeting at APO and NMSU this week.
• Ocotillo: The vibration stabilization bench and optical table have been delivered, along with the enclosure. We are starting to get optical mounting parts and a student is working on the software and data side. Late this week the fibers should arrive, and the optics will be coming in next few weeks, including the grating. Sarah plans to submit an NSF ATI proposal for the robot side of the third channel.

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. Status: CLOSED.
• 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. Status: CLOSED.
• UC reps: poll your users about a Jan. 2026 splinter session at the AAS for APO science highlights and networking (or other ideas!). Status: CLOSED.

New action items from this meeting:

• Nancy/Sarah: follow up with Jim Davenport about the status of PyKOSMOS and report back.
• Joanne Hughes: put the KOSMOS MOS data reduction software on the wiki.
• UC reps: remind your users to review the Q4 schedule and request OPEN/DD01 time if they can make a good case for it. Status: OPEN.
• UC reps: remind your users to provide Nancy with science highlights from 2025; she needs to receive them no later than Monday October 27. Status: OPEN.

We discussed the timeline of events that led to the temperature issues for KOSMOS. In January 2025 the chip temp increased. Data taken in late winter and early spring were probably not affected, but users started to notice the issue in the mid/late spring.

Gordon is working on a new release for TUI (v3.2), which will be coming soon. The new version cleaned out some old scripts and removed the option of selecting instruments that are being decommissioned. The most exciting aspect is that he is working on packaging to make the software installation process more simple for users, especially students. Although we encourage users to stay current with their TUI versions, older versions of the software will still work.

The next meeting is currently scheduled for Tuesday November 4, 2025, which directly conflicts with the ARC Board of Governors meeting. Therefore the November meeting is canceled, and we will meet next on Tuesday December 2, 2025, at 10:30 MST.