apo-wiki

Attending: Nancy Chanover (NMSU), Cary Smith (APO), Amanda Townsend (APO), Mike Skrutskie (UVa), Denise Stephens (BYU), Kevin Schlaufman (JHU), Michael Hayden (OU), Adam Kowalski (CU), Eric Bellm (UW), Moire Prescott (NMSU), Ben Williams (UW), Aleksandr Mosenkov (BYU), Chip Kobulnicky (UWy)

• Colorado - Adam reported an issue he's seen in his KOSMOS data. It is documented that arc lamps bleed over into the overscan for KOSMOS but the documentation does not mention this for the flat fields. In fact, the flat field slope is seen in the overscan at a level of few hundred counts. This calls into question whether the overscan region is very useful. The recommendation for users is that they take biases close in time to their flats. The APO team took an action to add this to the instrument manual page, and Adam will add it to the users wiki (or will send Nancy the text to be added).
• Williams - no report
• Colgate - no report
• Oklahoma - nothing to report
• BYU - nothing to report
• Wyoming - nothing to report
• Georgia State - no report
• UVa - nothing to report
• JHU - Kevin relayed a user question pertaining to the feasibility of using the 3.5m to observe the predicted impact of a Falcon 9 upper stage on the Moon in early August. Nancy indicated that she is also already thinking about trying to observe this and asked Kevin to put the user in contact with her directly, given her experience with this from observing the LCROSS impact.
• NMSU - nothing to report
• Washington - nothing to report

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

3.5-m Telescope and Instruments Highlights, 04/06/26 – 05/04/26

1) Overview

More than half of April was weathered out. Most of that was lost to cloud cover, elevated winds, and high humidity. We got very little precipitation during this time, but the first of May did experience some light snow showers with minimal accumulation. The latter portion of April into early May has cooled off noticeably.

The problem reported last month regarding DNS cache and reverse DNS lookups appears to be resolved with additional workarounds.

There were very few telescope or instrument problems reported in April.

In April, there was one class group here for on-site training. They were fortunate to be visiting during a few consecutive days of good weather.

2) Operations

3.5m Telescope: The telescope has been performing nominally. There were reported altitude motion errors on one night but no on-sky time was lost because these occurred on a cloudy night during test slews.

0.5m Telescope: Dcam and UVAcam are both available options for users. BYUcam has been returned to Utah. We continued to experience numerous problems with the main Windows-based computer on ARCSAT this past month. We have had to rebuild or put several cloned disks in the system. The power supply issues appear to be resolved, but we have identified a conflict with a web power switch in our network. The issue seems to have started when we installed our new Cisco routers. We continue to troubleshoot the issues. The telescope is available, in a shared-risk mode for the time being.

KOSMOS: System is cold and stable. Instrument is performing nominally.

ARCTIC: The diffuser rotation mechanism is still unreliable. We have manufactured some new parts, but have not gotten the opportunity to install and test them. The mechanism that moves the diffuser in and out of the optical path is still functional in the meantime. The instrument is working nominally otherwise.

ARCES: No failures seen this month in the thorium argon lamp power supply, resulting in lamp dropouts or weak lines. We are working to source a spare power supply from the vendor. If identified by an echelle user during their cals, the observing specialists have procedures to identify which is occurring and adjust the power supply or move the mirror by hand. Users are advised to carefully examine their calibration frames.

NICFPS: System is cooled and usable.

TripleSpec: System is cooled and usable.

APOLLO: The instrument is usable for laser ranging. Maintaining the instrument's temperature during extreme environmental conditions remains challenging. This past week, a new issue with the ACS system has occurred. The team has just started investigating.

Agile/ SoonerCam: Agile has been decommissioned. The Agile instrument rotator is still not performing nominally, and we will continue troubleshooting to prepare for SoonerCam. SoonerCam parts are on hand, assembled, and software development has begun. Software development is in the early stages of learning the Hamamatsu and Brandywine software APIs.

DIS: DIS has been decommissioned.

April was heavily impacted by weather. The DNS issues seem to be resolved, resulting in improved computer connectivity. All instrument performance was normal until few days, when two unrelated KOSMOS issues cropped up. First, the KOSMOS guide camera seems to have ice condensing on the CCD, which manifests as artifacts appearing in the images. The guider still guides but this is being evaluated. Second, a user reported artifacts appearing in dark frames; it seems to be suggestive of a light leak that allowed some ambient light in and caused an internal reflection. Amanda took some more test data to try and reproduce it and is Cary working on trying to understand the source. We hope to have more information soon. ARCSAT is still offered in shared risk mode given the recent computer problems.

The Q2 schedule is posted. There is very little unassigned time because of numerous partial night programs. Both unassigned DD half nights are dark B halves in June. Users can request this time at any point although given that it is later in the quarter we likely will not make a decision about it immediately.

The 3.5m summer shutdown is scheduled for July 20 - August 2. The institutional allocations for Q3 were sent out yesterday; proposals are due on May 26.

The ARCSAT Q2 schedule is posted. There is one open week at the end of June.

Denise Stephens presented an overview of the report completed by the Future of ARCSAT Working Group (FAWG), which she chaired. The charge for this group was to identify current use cases for ARCSAT, assess its current capabilities, and explore future options for making it more useful for the ARC user community. The FAWG conducted an ARC-wide survey, for which they received 61 responses. The survey results indicated that there is still a strong demand for an 0.5m telescope for teaching, training, and scientific uses, but nearly half of the respondents said that ARCSAT in its current form would not meet their future needs. The FAWG examined telescope needs first, followed by cameras, user interface, and possible observing modes. The overarching concern is the reliability of the current ARCSAT, noting that it is one critical failure away from being unusable. The FAWG provided a suite of recommendations with different cost points, which the 3.5m leadership team will evaluate in preparation for making a recommendation to the ARC Board. Nancy expressed appreciation for the time and effort that the FAWG members put into this task. She will post the final version of the FAWG report after receiving it.

Nancy expressed an interest in collecting more information from the users concerning the impact that the 3.5m has had on grants being awarded to researchers at ARC member institutions. She already collects related information from users at two different points in the year: publications resulting from 3.5m/ARCSAT data in June-July, and science highlights for ARC Board meeting in October. She will add the grant information request to one of these calls.

Open action items from previous meetings:

• UC reps: ask your users to provide instrument usage/data reduction tips and tricks to Jon Holtzman for inclusion on the wiki. No further activity on this topic. Status: CLOSED.
• APO: check out recently reported ARCSAT issue to see if can reproduce it and/or determine its cause. Status: CLOSED.
• CU: Adam K. to provide some examples of ghost spectra for KOSMOS documentation, and APO could potentially take some bright object spectra during engineering time to learn more about these effects. Status: CLOSED.
• Nancy will ensure that the final report from the Future of ARCSAT Working Group is made available to the Users Committee so that it can be added to the agenda for our next meeting. Status: OPEN (pending receipt of final version of report).

New action items from this meeting:

• APO team: update KOSMOS user manual web page regarding issue of flats bleeding into overscan region.

None.

The next Users Committee meeting will be on Tuesday June 02 at 10:30 MDT.

Attending: Nancy Chanover (NMSU), Aleksandr Mosenkov (BYU), Kevin Schlaufman (JHU), Russet McMillan (APO), Anne Verbiscer (UVa), Chip Kobulnicky (UWy), Bill Ketzeback (APO), Eric Bellm (UW), Moire Prescott (NMSU), Sarah Tuttle (UW), Misty Bentz (GSU), Adam Kowalski (CU), Ben Williams (UW)

• Washington - nothing to report
• NMSU - nothing to report
• Colorado - nothing to report
• JHU - had a question about whether the process for requesting open ARCSAT time is the same as for requesting OPEN/DD time on the 3.5m (it is the same - please send all requests for open ARCSAT time to Ben Williams, Russet McMillan, Amanda Townsend, and Nancy Chanover)
• UVa - nothing to report
• Georgia State - nothing to report
• Oklahoma - no report
• Wyoming - nothing to report
• BYU - nothing to report
• Williams - no report
• Colgate - 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, 03/03/26 – 04/06/26

March was a busy month here at the observatory.

Most of March was drier and warmer than normal, with plenty of on-sky time. Weather downtime was typically due to high winds and high dust levels, though we lost a small handful of partial nights to elevated humidity. We are in fire season again, and we had a wildfire about 40 miles northeast of the observatory that brought elevated smoke levels one night. The human-caused wildfire is currently 90% contained.

We held the APO Site Infrastructure Review here at the observatory on March 11-13. It was a positive experience for both the reviewers and staff. The reports (Infrastructure Committee and Water Subcommittee) have been shared with the ARC board members. There will be a special board meeting with the external reviewers later this month to discuss the report and develop implementation plans for some of their recommendations. A special thank you to the staff for all their hard work preparing presentations, quotes, and answering the reviewers' insightful questions.

A small number of events occurred in which the NA2 rotator lost communication with the telescope control software. We changed the memory card in the controller and are currently monitoring for additional incidents. Overall, the telescope and instruments performed well.

We are working on a problem with our DNS cache. We believe that recent software updates to the site firewall have caused conflicts with the configuration of the old DNS machine. Reverse DNS lookups have caused slowdowns or outages on our network for both telescopes. We have implemented some workarounds, but we will need to reengineer the on-site DNS architecture.

In March, in addition to the on-site infrastructure review, we had two visiting instrument teams, one on-site first-time PhD observer, and three class groups here for on-site training. All got data on sky and left quite happy.

2) Operations

3.5m Telescope: The telescope has been performing nominally. A few instances of changing instrument ports resulted in communication failures between the telescope control computer and the NA2 rotator again this month. An increase of last month. A software restart corrected the problem with minimal time lost on sky. As a precaution, we cleaned all communication port connections. This did not solve the problem, so we have replaced the compact flash card in the controller. We will monitor for additional events. No additional instances of secondary mirror actuator errors were observed this past month. One reported altitude motion error as the ambient temperature has started to rise.

0.5m Telescope: Dcam and UVAcam are both available options for users. We had a significant failure of the Windows computer that runs most of the application software (ACP, FocusMax, MaxIm DL). The main hard drive was on the verge of failure, so we cloned and replaced it. A short time later, power-related problems appeared to affect only this machine. We suspect the power supply or possibly the UPS that supplies it. Parts are on order and may not arrive until later in April. The telescope is unavailable for the time being while we work on this problem.

KOSMOS: System is cold and stable. Instrument is performing nominally.

ARCTIC: The diffuser rotation mechanism is still unreliable. We have manufactured some new parts, but have not had the opportunity to install and test them. The mechanism that moves the diffuser in and out of the optical path is still functional in the meantime. There was one instance of a quad drop, likely due to user error.

ARCES: No failures seen this month in the ThAr lamp power supply, resulting in lamp dropouts or weak lines. We are working to source a spare power supply from the vendor. If identified by an echelle user during their cals, the observing specialists have procedures to identify which is occurring and adjust the power supply or move the mirror by hand. Users are advised to carefully examine their calibration frames.

NICFPS: System is cooled and usable.

TripleSpec: System is cooled and usable.

APOLLO: The instrument is usable for laser ranging. Maintaining the instrument's temperature during extreme environmental conditions remains challenging.

SoonerCam: The agile instrument rotator is still not performing nominally, and we will continue troubleshooting to prepare for SoonerCam. SoonerCam parts are on hand, assembled, and software development has begun. Software development is in the early stages of learning the Hamamatsu and Brandywine software APIs.

DIS: System is powered down and warm. Decommissioning plans have begun. The instrument has been decabled, and we will be lowering it off the observing floor before the summer shutdown.

We are getting some much needed moisture today at the observatory (it's currently snowing!). March was warmer/drier than normal, which means we have been experiencing the spring wind/dust pattern early. The wildfire mentioned in the above site report is now fully contained. The Site Infrastructure Review report was recently sent to the ARC Board. There was a recent NA2 rotator issue; we changed out the memory card for the computer that calculates velocity, accelerations, etc. and now it seems better. A problem with the DNS cache on site has been causing local connectivity slow-downs. Shane is working with our provider to schedule the work to repair this issue. Users from off-site should not notice a change other than possibly fewer TUI dropouts.

The 0.5m had a severe computer failure, first a hard drive issue and then power-related problems. That machine is now back in the dome and we are running diagnostics now. If things go well then some of the time early in Q2 that is currently listed as unavailable may be freed up to be scheduled.

Most of the 3.5m instruments are behaving well. There was a quad drop on ARCTIC and a restart of NICFPS after freezing up over the last week. SoonerCam development continues. We had some visitors from NASA working on APOLLO for some satellite ranging tests last week.

During some recent engineering time we tried to replicate the issue that Adam K. reported last month (ghosting in KOSMOS spectra of bright sources). We will need to do a real-time comparison with him to better understand what he is seeing; Adam will send some files out to illustrate what he's referring to.

The Q2 schedule is posted. There is very little unassigned time because of numerous partial night programs. Both unassigned DD half nights are dark B halves in June. Users can request this time at any point although given that is later in the quarter we likely will not make a decision about it immediately.

The ARCSAT Q2 schedule is posted. Russet advised Sarah (the first user after the scheduled down time for repairs) to be cautious about observing planning with her students.

• SoonerCam: See above site report and subsequent discussion.
• KOSMOS grisms: We have requested an updated quote for the low-res grism and will be ordering it as soon as it is received.
• ASPEN: No major updates this month. We still plan to hold the Preliminary Design Review in June 2026.
• Ocotillo: All optics are in house for first channel but one compound piece that is scheduled for deliver in June, and assembly has started on the opto-mechanical structure. Sarah added several undergraduate and graduate students to her team and they are now working on fiber manufacturing.

We have received lots of valuable input, found a lot of broken links, and have been working on improving accessibility of information and general flow of the site. Users are reminded to do a full reload when accessing the website so that they are not using a cached version. If users find a broken link please let us know so we can fix it!

Open action items from previous meetings:

• UC reps: ask your users to provide instrument usage/data reduction tips and tricks to Jon Holtzman for inclusion on the wiki. Status: OPEN.
• APO: check out recently reported ARCSAT issue to see if can reproduce it and/or determine its cause. Status: CLOSED.
• CU: Adam K. to provide some examples of ghost spectra for KOSMOS documentation, and APO could potentially take some bright object spectra during engineering time to learn more about these effects. Status: CLOSED.

New action items from this meeting:

• Nancy will ensure that the final report from the Future of ARCSAT Working Group is made available to the Users Committee so that it can be added to the agenda for our next meeting.

None.

The next Users Committee meeting will be on Tuesday May 05 at 10:30 MDT.

Attending: Bill Ketzeback (APO), Misty Bentz (GSU), Anne Verbiscer (UVa), Aleksandr Mosenkov (BYU), Kevin Schlaufman (JHU), Moire Prescott (NMSU), Michael Hayden (OU), Adam Kowalski (CU), Ben Williams (UW), Sarah Tuttle (UW)

• Wyoming - no report
• Williams - no report
• Washington - nothing to report (sent by email)
• UVa - user had a hard time with ARCSAT the other night (Chrome requiring permission… older version of Chrome and Mac OS… two users using same port, which again, worked with older version)
• Oklahoma - nothing to report
• NMSU - nothing to report
• JHU - nothing to report
• Georgia State - nothing to report
• Colorado - broken links found on website
• Colgate - no report
• BYU - nothing to report

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

3.5-m Telescope and Instruments Highlights, 02/03/26 – 03/02/26

1) Overview

February was a good month, with plenty of on-sky time. There was an average number of nights affected by cloud cover or elevated humidity. One night was lost to rain, snow showers, and fog.

There was another actuator problem on the secondary mirror this month, which was resolved by homing. Another night, there was a problem with the NA2 rotator that was quickly resolved by rebooting the axis controller. Otherwise, the telescope and instruments performed well.

Two groups were on site for training. One visiting instrument team is currently on site.

2) Operations

3.5m Telescope: The telescope has been performing nominally. We experienced another instance this month of an actuator for the secondary mirror failing to reach or move to the commanded position. The problem was corrected at the end of the night by homing the secondary. No on-sky time was lost. The trouble is intermittent, making troubleshooting difficult because it cannot easily be reproduced. A communication failure between the telescope control computer and the NA2 rotator occurred this past week. A software restart corrected the problem with minimal time lost on the sky.

0.5m Telescope: Working as expected. Dcam and UVAcam are both available options for users.

KOSMOS: System is cold and stable. Instrument is performing nominally.

ARCTIC: The diffuser rotation mechanism is still unreliable. We have manufactured some new parts, but have not gotten the opportunity to install and test them. The mechanism that moves the diffuser in and out of the optical path is still functional in the meantime.

SoonerCam: The agile instrument rotator is still not performing nominally, and we will continue troubleshooting to prepare for SoonerCam. SoonerCam parts are on hand, assembled, and software development has begun. Software development is in the early stages to learn the Hamamatsu and Brandy Wine software APIs.

ARCES: There was another intermittent failure of the thorium argon lamp power supply, resulting in lamp dropouts or weak lines. Another instance of trouble with the ThAr calibrations was not the lamp power supply, but the calibration flip mirror not moving into place. If identified by an echelle user during their cals, the observing specialists have procedures to identify which is occurring and adjust the power supply or move the mirror by hand. Users are advised to carefully examine their calibration frames.

NICFPS: System is cooled and usable.

TripleSpec: System is cooled and usable.

APOLLO: The instrument is usable for laser ranging. Maintaining the instrument's temperature during extreme environmental conditions remains challenging.

DIS: System is powered down and warm. Decommissioning plans have begun. The instrument has been decabled, and we will be lowering it off the observing floor soon.

Hard time with ARCSAT the other night (Chrome requiring permission… older version of Chrome and Mac OS… two users using same port, which again, worked with older version). Sarah notes that they have had 10 users on the same port without problems in the past. Shane is aware this problem occurred, but may want to loop in Gordon.

APOLLO got returns during the eclipse, so is functioning well.

The Q1 schedule is posted and there are no empty slots remaining.

The Q2 schedule is in development now.

The ARCSAT Q1 schedule is posted; there is one open week remaining at the end of the quarter. The call for Q2 requests will go out after the 3.5m schedule for Q2 is completed.

• SoonerCam: See above site report and subsequent discussion.
• KOSMOS grisms: We have requested an updated quote for the low-res grism and will be ordering it as soon as it is received.
• ASPEN: No major updates this month. We still plan to hold the Preliminary Design Review in Q2 2026.
• Ocotillo: All optics are in house for first channel but one compound piece, and assembly has started on opto-mechanical structure.

The web dev team met with Jon and Anne to discuss improvements to landing pages, and simplification of menus to improve public facing pages and make most popular information easier to find. CU users found some broken links and will send them to Shane or Ben to get fixed.

Open action items from previous meetings:

• Joanne Hughes: put the KOSMOS MOS data reduction software on the wiki. Joanne is waiting for an update from her colleagues at the College of Idaho. Update: Jon Holtzman put a link to the College of Idaho software on the wiki, and notes that this is a wrapper for lower level reduction stuff in pyVista. Additional descriptive text/examples would still be welcome and good. Status: CLOSED
• UC reps: ask your users to provide instrument usage/data reduction tips and tricks to Jon Holtzman for inclusion on the wiki. We have received no feedback yet so this will remain OPEN.
• UC reps: ask your users if they have experience using PypeIt with non-APO instruments; if so please contact Jon. No one seems knows anyone in this category … move to CLOSED.
• Nancy: ensure that observatory lat/long/elevation gets put back on new APO home page. Status: CLOSED
• Nancy: explore web page hackathon idea with APO webdev team. Status: CLOSED

New action items from this meeting:

• ARCSAT issue should get checked out to attempt to determine cause or see if it can be reproduced.
• Adam noted some ghosting effects he's seeing in bright object KOSMOS spectra. He may send in some examples of ghost spectra for KOSMOS documentation, and potentially could take some bright object spectra during engineering to learn more about these effects.

Grisms: Any update on high resolution prisms? Low res was easy to decide, but high-res is harder because one needs to choose the part of the spectrum, and there is not consensus.

KOSMOS: Zeroth order effect could use more information (how it manifests in various setups). Adam is seeing ghost spectra in some spectral setups. Is there anything about this in the documentation? Suggestions for order-blocking filters? Not available if you want to observe in the blue, and may actually cause reflections. More information about those would be appreciated. Added an action item.

The next Users Committee meeting will be on Tuesday April 07 at 10:30 MDT.

Attending: Nancy Chanover (NMSU), Bill Ketzeback (APO), Misty Bentz (GSU), Anne Verbiscer (UVa), Aleksandr Mosenkov (BYU), Kevin Schlaufman (JHU), Eric Bellm (UW), Jon Holtzman (NMSU), Moire Prescott (NMSU), Chip Kobulnicky (UWy), Michael Hayden (OU), Ben Williams (UW)

Nancy started by announcing the newest member of the 3.5m observing team: Harrison (Harry) Abbot started his position at APO a few weeks ago. We will introduce him at a later date, although some of you may meet him online (over TUI) in the meantime.

• JHU - The longitude/latitude/elevation of APO used to be easily findable at the top of the APO home page. This information is important for many users so please add it back in. Nancy agreed and will ensure that this gets done.
• NMSU - A user recently reported seeing a higher dark current rate with KOSMOS; the values were elevated from what they saw in November-December after the last repair. This is seen in longish (1200 sec) exposures, although it seems to be present in the Dark frames but not necessarily in the science frames (which leads to an over-subtraction when removing the dark current). The APO staff will take a look at this in more detail and will use this information as they develop the KOSMOS repair schedule.
• Oklahoma - nothing to report
• Wyoming - nothing to report
• Williams - no report
• BYU - nothing to report
• UVa - nothing to report from users; Anne thanked APO for keeping the legacy website up. We discussed the website later in the agenda.
• Georgia State - one user responded to Misty's request for feedback regarding having APO data made available in a public archive (after a proprietary period). The user said it would be really helpful for them since they are trying to locate historical data taken from APO.
• Colorado - no report
• Washington - nothing to report
• Colgate - 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, 01/14/26 – 02/02/26

1) Overview

The first half of January was typical wintery weather for APO, with a mix of clouds and 2 inches of fresh, powdery snow that melted within two days. During this same storm, we experienced our coldest weather of the season, down to -12C with winds above the closure limits, making for a couple of very cold nights. The last week of the month, however, Winter Storm Fern, which had affected much of the United States, left the observatory under a blanket of ice and 20+ inches (50 cm) of heavy, wet snow. Utility power to the site was interrupted. APO remained on emergency generator power for a week. Multiple trees were down on utility lines on the way to the observatory (and around the mountain), resulting in more than a dozen power poles damaged or sheared off over a 5-kilometer-long path. It took electric crews a week to replace poles and power lines in difficult terrain and deep snow before electricity was restored to communities along the Sunspot Highway to Timberon. Linemen from several electric companies were contracted to assist in the repairs. Utility power was restored to the Observatory this past Thursday evening (on January 29), but significant snow drifts and ice buildup remained on the 3.5m enclosure over the weekend. Staff have been orienting the enclosure to maximize sun exposure over the weekend to clear the roof.

We had an on-site documentary filmmaker from the Fisk Planetarium visit during this time period.

2) Operations

3.5m Telescope: The telescope has been performing nominally. We experienced another instance this month of a collimation failure due to software time-outs, when one of the actuators for the secondary mirror did not reach or move to the commanded position. The next move seemed to correct itself. We have identified additional instances of the same error over the past several months, which we are investigating further. The problem is intermittent, making troubleshooting difficult because it cannot be reproduced.

0.5m Telescope: Working as expected. Dcam and UVAcam are both available options for users.

KOSMOS: System is cold and stable. Instrument is performing nominally.

ARCTIC: The diffuser rotation mechanism is still unreliable. We have manufactured some new parts, but have not gotten the opportunity to install and test. The mechanism that moves the diffuser in and out of the optical path is still functional in the meantime. The L1 lens was cleaned, and a full vacuum servicing was performed in January. Work was delayed, and some planned tasks were cancelled due to weather conditions.

SoonerCam: The Agile instrument rotator is still not performing nominally, and we will continue troubleshooting to prepare for SoonerCam. SoonerCam parts are on hand, assembled, and software development has begun. Software development is in the early stages to learn the Hamamatsu and Brandy Wine software APIs.

ARCES: There was another intermittent failure of the thorium argon lamp power supply, resulting in lamp dropouts or weak lines. Another instance of trouble with the ThAr calibrations was not the lamp power supply, but the calibration flip mirror not moving into place. If identified by an echelle user during their cals, the observing specialists have procedures to identify which is occurring and adjust the power supply or move the mirror by hand. Users are advised to carefully examine their calibration frames.

DIS: System is powered down and warm. Decommissioning plans have begun. The instrument has been decabled, and we will be lowering it off the observing floor soon.

NICFPS: System is cooled and usable.

TripleSpec: System is cooled and usable.

APOLLO: The instrument is usable for laser ranging. Maintaining the instrument's temperature during extreme environmental conditions remains challenging. The team has experienced a streak of poor weather and software connection issues over the past month.

The recent winter storm that affected a large swath of the US dumped heavy rain for 6-8 hours, which then froze, followed by about 2 feet of snow. Trees were weighted down by frozen ice and snow, which led to a number of downed limbs, trees, and power poles. The site lost power and was on generator power for about a week. Fortunately, the generator worked as expected throughout the entire week. We are now open and can observe again as of last night (Monday February 2).

There was a documentary filmmaker on site for an SDSS planetarium presentation.

There was a telescope issue (described above); we are still trying to determine if it is a hardware or software issue.

Yesterday we learned of the recent elevated dark current for KOSMOS (see above), which we will investigate ASAP.

A servicing of ARCTIC was completed last month, including cleaning the L1 lens and vacuum servicing. Additional planned work on the diffuser rotation mechanism was halted because of the bad weather. Those potential upgrades are still in the works.

The early software development for SoonerCam is still ongoing.

We are still having issues with the ARCES ThAr lamps; users should carefully examine their calibration frames and report any unusual behavior to the observing specialist. The ThAr and possibly quartz frames will be blank or have very low signal when things are not functioning correctly.There are two failure modes and the obs-specs know how to identify each one and what to do to remedy it.

There are no current issues with TripleSpec and NICFPS. The DIS and Agile decommissioning is still ongoing. APOLLO has been having some thermal issues due to the cold weather, which we are continuing to troubleshoot.

There is an open position for a mechanical engineer to join the 3.5m engineering group. This is at a more junior level than the Chief Telescope Engineer position that was advertised previously. Please share this advertisement with any qualified candidates! https://careers.nmsu.edu/jobs/mechanical-engineer-remote-locations-new-mexico-united-states

The Q1 schedule is posted. It is pretty full at this point, although there is an available B half (DD01) on February 11. Users interested in requesting this time should send the request (including a program ID if the project already has been assigned time this quarter, otherwise a short proposal) to Ben, Nancy, Russet, Amanda, and their institutional schedulers.

The allocations were sent out to institutional schedulers last night. Proposals are due on February 24. We are aware of one class group that plans to visit APO during Q2 but if there are others who have not yet notified us please do so ASAP.

The ARCSAT Q1 schedule is posted; there is one open week remaining at the end of the quarter.

Jon Holtzman led a discussion of the APO wiki (http://astronomy.nmsu.edu/apo-wiki/doku.php?id=start), which he has been cleaning up recently. While the instrument manuals on the APO website are fine for learning basic properties and operational procedures of the instruments, information about “features” or “issues” for each instrument (e.g those related to data processing or tricks/tips for observing in a very specific mode) are not held in a common repository despite the vast experience spread around the ARC user community. This would be particularly useful for new users, students, etc. The user wiki was designed for this, but it has been fairly stagnant lately. Jon is leading an effort to revitalize the wiki and populate it with things that users should be aware of and provide some descriptions of reduction issues and software options. Therefore Jon is trying to collect 1) a list of features/issues for each instrument, provided by users, and 2) a list of the software options for data reduction for each instrument (no judgment here - truly, what are people using?). He needs help populating these two sections for each instrument! If you have and information regarding either of these items, please email it to Jon Holtzman (holtz@nmsu.edu) so he can add it to the wiki. This will ultimately help all users achieve the pest possible performance from the 3.5m facility instruments for their science.

Jon Holtzman is also working on incorporating modules into PypeIt for reducing spectra from 3.5m instruments. PypeIt is designed primarily for data from slit spectrographs, and we have received funding as part of an NSF award to develop a PypeIt implementation for KOSMOS, ARCES, and TripleSpec. Initial modules have been created for all three instrument; ARCES is challenging because of its short slit, but the versions for KOSMOS and TripleSpec are nearing usability for testing. The PypeIt group does an excellent job in version controlling their software; in order for a new module to be incorporated into the overall distribution version, new modules need to be supplied with test data so that any time modifications are made to the code base they can be applied to the test data. In order to move us closer towards being able to implement the new APO-specific modules, we are looking for users in the ARC community that have familiarity w/PypeIt for non-APO instruments and are willing to test out our development modules. There are lots of parameters that can be tuned, and we're looking for people who have experience in doing so. UC reps: please query your users and have them contact Jon if they are willing to help with this.

• SoonerCam: See above site report and subsequent discussion.
• KOSMOS grisms: We received a number of useful responses to the recent survey - THANK YOU! The low-res grism is the highest priority for a significant majority of the respondents so we will move forward with purchasing that grism immediately as we continue to seek funds for the purchase of additional grisms.
• ASPEN: No major updates this month. We still plan to hold the Preliminary Design Review in Q2 2026.
• Ocotillo: No major updates this month. The TEG will be hiring an engineer/technician at the BS/MS level very soon; interested parties should look for the job ad on the UW hiring site shortly.

Nancy stated that we'd like to understand what users are not able to find/do on the new website in an effort to encourage users to move to that one. One user suggested getting rid of the drop-down menus on the front page and restoring all the links to the front page. Or at minimum, reducing the number of clicks that it takes to reach specific information. Another user mentioned that there are no Exposure Time Calculators for any of the instruments. Bill stated that we have tried for the last 15 years to get ETCs for all instruments but these have not been completed. Another user mentioned that there is no front page that gives an overview of all the instrument. We concluded that an efficient way to address some of these issues would be to schedule a hackathon where users could meet in real time with the web development team to discuss and implement suggestions. Nancy and Ben will discuss this further with the IT staff.

Open action items from previous meetings:

• Joanne Hughes: put the KOSMOS MOS data reduction software on the wiki. Joanne is waiting for an update from her colleagues at the College of Idaho. Update: Jon Holtzman put a link to the College of Idaho software on the wiki, and notes that this is a wrapper for lower level reduction stuff in pyVista. Additional descriptive text/examples would still be welcome and good. Status: CLOSED
• UC reps: remind your users to review the Q1 schedule and request OPEN/DD01 time if they can make a good case for it. Status: OPEN.

New action items from this meeting:

• UC reps: ask your users to provide instrument usage/data reduction tips and tricks to Jon Holtzman for inclusion on the wiki.
• UC reps: ask your users if they have experience using PypeIt with non-APO instruments; if so please contact Jon.
• Nancy: ensure that observatory lat/long/elevation gets put back on new APO home page.
• Nancy: explore web page hackathon idea with APO webdev team.

None.

The next Users Committee meeting will be on Tuesday March 03 at 10:30 MST.

Attending: Nancy Chanover (NMSU), Kristian Finlator (NMSU), Bill Ketzeback (APO), Michael Hayden (OU), Aleksandr Mosenkov (BYU), Ben Williams (UW), Misty Bentz (GSU), Kevin Schlaufman (JHU), Anne Verbiscer (UVa), Amanda Townsend (APO), Adam Kowalski (CU), Chip Kobulnicky (UWy), Sarah Tuttle (UW), Shane Thomas (APO)

• Wyoming - nothing to report
• Williams - nothing to report (by email)
• Washington - nothing to report (by email)
• UVa - Anne is currently unable access the observing schedule on the new website and does not see a way to access the old website as was promised last month (this was discussed later in the meeting)
• Oklahoma - nothing to report
• NMSU - nothing to report
• JHU - nothing to report
• Georgia State - nothing to report
• Colorado - nothing to report
• Colgate - no report
• BYU - Aleksandr reported that a user who tried to sign up for an account on the new website discovered that BYU was not listed as an institution option (this was discussed later in the meeting)

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

3.5-m Telescope and Instruments Highlights, 12/02/25 – 01/13/26

1) Overview

The past month was a mix of excellent skies and very unsettled weather. About a third of the time was lost due to clouds, wind, and a few days when we could not open the enclosure due to an ice and snow storm.

We had one student training visit during this time period.

2) Operations

3.5m Telescope: The telescope is working quite well. We experienced one instance of collimation failure when one of the actuators for the secondary mirror did not reach or fail to move to the commanded position. The problem was corrected by homing the mirror. A moderate correction to collimation was applied during engineering last week.

0.5m Telescope: Telescope is working as expected. Dcam-spare was having issues with the CCD chamber frosting up. Even after multiple attempts, it could not be cleaned or made reliable. We pulled Dcam off of DIS and put it into service. Dcam and UVAcam are both available options for users.

KOSMOS: System is cold and stable. The instrument dispenser wheel had one instance of not moving when commanded. It was corrected by manually repositioning it. There was one night when the camera focus was not properly set, and some confusion resulted when the telescope focus seemed to be running low. It was corrected the next night. Some of the silicon wafers manufactured with slits have been damaged in their holders. They appear to have developed stress cracks from the differential thermal expansion of the aluminum holders. We are currently seeking companies that may be able to manufacture spares.

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. There was another instance this month of the filter wheel controller losing connection and requiring a reset. On another night, the instrument refused to take an exposure because another one was in progress that would not clear. An init resulted in a dropped upper left quad. The observer got back on the sky, using single amplifier mode. During the holiday break, a failure of the ion pump resulted in a loss of vacuum. The repair required a swap of the ion pump, putting the instrument back on a vacuum pump, a different ion pump controller, and a cable. Special thanks to Cary Smith, who came in over his time off to restore the instrument.

SoonerCam: The agile instrument rotator is still not performing nominally, and we will be troubleshooting it further to prepare for SoonerCam. SoonerCam parts are on hand, assembled, and software development has begun. The first biases using low-level commands were taken this past week.

ARCES: There was an intermittent failure of the thorium argon lamp power supply, resulting in lamp dropouts or weak lines. Cleaning the rheostat that controls the adjustment of amperage was a temporary fix until we can possibly repair it with a new part.

DIS: System is powered down and warm. Decommissioning plans have begun. The instrument has been decabled, and we will be lowering it off the observing floor soon.

NICFPS: System is cooled and usable.

TripleSpec: System is cooled and usable.

APOLLO: The instrument is usable for laser ranging. The team has experienced a streak of poor weather and software connection issues over the past month.

There was one student group that visited last month. We've had some winter weather and were closed for two nights due to ice on the enclosure and lightning arrestors.

As for instruments, both KOSMOS and ARCTIC each had some problems last month. There was an instance when the KOSMOS disperser wheel was commanded and then got stuck; this was remedied by the operator going up to the observing level and moving it by hand. We had one instance where the camera focus wasn't set properly and caused confusion regarding the telescope focus; this was corrected. We've seen some stress cracks in the UW-manufactured silicon wafer slits, likely due to differential expansion of the aluminum holders. We are working to identify a manufacturer for new spares/replacements.

ARCTIC had a failure of the filter wheel; this was discovered by an observing specialist in the afternoon and fixed by the engineering staff that same day so it did not impact observing. We had another instance where the instrument exposure was stuck and could not be commanded to take another. An init was done, which caused a dropped quad, and the user elected to observe in the single amplifier mode for the rest of night. We had a more serious issue with an ion pump that resulted in loss of vacuum to the instrument. This was due to a failure of a high voltage cable that became welded to the pump; both needed to be replaced. Special thanks for Cary Smith who came in during his time off during the winter break to restore the instrument.

First biases were achieved with the new SoonerCam setup. We are starting to develop the new ICC software and trying to learn the lower level commands for triggering the camera.

We've seen an intermittent failure of the ARCES ThAr lamp power supply, We cleaned the connectors and this seemed to help but the issue still sporadically appears. Users should check their ThAr exposures to make sure they have enough lines with appropriate S/N levels.

DIS decommissioning continues; the instrument is decabled but still on the observing floor for now.

There have been no issues with TripleSpec or NICFPS, and APOLLO has been working well.

We have completed hiring process for a new Support Astronomer (observing specialist). Harrison (Harry) Abbot will begin his work and training in a few days.

There will be a site infrastructure review held at APO next month. The goal is to review overall site and telescope infrastructure items (excluding instruments) in order to develop priorities for resource allocation in order to ensure that we maintain a highly functioning observatory.

The Q1 schedule is posted. There is some OPEN time available on Jan 18A and also in February and March. Users interested in requesting any of that time should send the request (including a program ID if the project already has been assigned time this quarter, otherwise a short proposal) to Ben, Nancy, Russet, Amanda, and their institutional schedulers.

The ARCSAT Q1 schedule is posted; there is one open week remaining at the end of the quarter.

• SoonerCam: See above site report and subsequent discussion.
• KOSMOS grisms: our proposal requesting funds to support the purchase of three new grisms for KOSMOS was not selected. We will move forward with the purchase of one or two grisms using ARC funds. If users have an opinion about this they should complete the following form no later than Friday January 30: https://forms.gle/Fr6LVu9o8Up782hW7
• ASPEN: we have an NSF proposal pending but learned that we did receive some funds from the State of New Mexico to further advance the design. We will move forward with building the atmospheric dispersion corrector first since it can be used with ARCES. We presented a poster about ASPEN at the Jan. 2026 AAS meeting and received some positive feedback, and we submitted several papers about the instrument for the SPIE conference this summer. We still plan to hold the Preliminary Design Review in the first half of 2026, likely now in Q2.
• Ocotillo: Things are progressing; we have the camera in hand and someone is working on camera characterization and software. We have the grating, some optics, and the fiber in hand. The TEG will be hiring an engineer/technician at the BS/MS level very soon; interested parties should look for the job ad on the UW hiring site shortly.

We flipped the switch this morning so that https://mainapo.apo.nmsu.edu became https://www.apo.nmsu.edu. This resulted in some preliminary problems as some certificates needed to be updated in order to preserve the old web site (which will be located at legacy.apo.nmsu.edu). We hope to have these sorted out by the end of the day. The links to the observing schedules are currently not working, but one can still access the Q1 schedule using this direct link: http://35m-schedule.apo.nmsu.edu/2026Q1.shtml. Shane will fix Aleksandr's reported issue ASAP. If users have difficulties finding what they need on the new site please let us know ASAP!

We had a booth alongside SDSS and SciServer so there was a strong APO presence at the Jan. 2026 AAS meeting in Phoenix. We were well positioned in the exhibit hall and received a lot of foot traffic; we gave away a lot of swag.

Open action items from previous meetings:

• Joanne Hughes: put the KOSMOS MOS data reduction software on the wiki. Joanne is waiting for an update from her colleagues at the College of Idaho. Update: Nancy connected with the folks working on this while at the AAS meeting so we are getting closer to have this software in hand and made available to the user community through the wiki. Status: OPEN.
• UC reps: please discuss the idea of archiving our 3.5m data with your users and report back with any reactions, either positive (e.g., advantages that they see to having a data archive) or negative (e.g., potential issues or concerns). No UC reps reported any feedback from users so we will be moving forward with piloting this as a next step. Status: CLOSED.

New action items from this meeting:

• UC reps: remind your users to review the Q1 schedule and request OPEN/DD01 time if they can make a good case for it.

None.

The next Users Committee meeting will be on Tuesday February 03 at 10:30 MST.