ARC 3.5-m Instrument News Page

Apache Point Observatory
New Mexico, USA

ARC 3.5-m Instrument News

Note: Comments in bold are to catch the readers attention as the most relevant for their upcoming science observations

News Worthy Items

ARCES is available. See below for more information.
DIS is NOT available. See below for more information.
AGILE is available. See below for more information.
ARCTIC is available. See below for more information.
KOSMOS is available but at shared risk. See below for more information.
NICFPS is available. See below for more information.
Triplespec is available. See below for more information.

Current Status

Instrument issues which our users should be aware of before taking data. For historical information go here. For future instrumentation or planned upgrades go here.

AGILE

2021-10-11: Instrument is operating nominally.
2021-10-04: Instrument is operating nominally.
2021-09-27: Instrument is operating nominally.
2021-09-20: Instrument is operating nominally.
2021-09-18: Instrument is operating nominally.
2021-09-13: Instrument is operating nominally.
2021-09-06: Instrument is operating nominally.
2021-08-30: Instrument is operating nominally.
2021-08-09: Instrument is operating nominally.
2021-08-02: Instrument is operating nominally.
2021-07-26: Instrument is operating nominally.
2021-07-12: Instrument is operating nominally.
2021-07-06: Instrument is operating nominally.
2021-06-28: Instrument is operating nominally.
2021-05-24: Instrument is operating nominally.
2021-05-17: Instrument is operating nominally.
2021-05-11: Instrument is operating nominally.
2021-05-04: Instrument is operating nominally.
2021-04-19: Instrument is operating nominally.
2021-04-12: Instrument is operating nominally.
2021-04-05: Instrument is operating nominally.
2021-03-29: Instrument is operating nominally.
2021-02-22: Instrument is operating nominally.
2021-02-15: Instrument is operating nominally.
2021-02-08: Instrument is operating nominally.
2021-02-01: Instrument is operating nominally.
2021-01-25: Instrument is operating nominally.
2021-01-18: Instrument is operating nominally.
2021-01-11: Instrument is operating nominally.
2021-01-05: Instrument is operating nominally.
2012-01-24: APO still does not recommend taking dome flats with AGILE. More information can be found here.

ARCES

2021: Most recent interorder ratio plot can be found here.
2021-10-11 The instrument CCD is cold. IOL ratios are showing a very slow improvement in the bluest orders, still at low but acceptable levels. IOL ratios in the blue are at a peak value since spring of 2019.
2021-10-04 The instrument CCD is cold. IOL ratios are showing a very slow improvement in the bluest orders, still at low but acceptable levels. IOL ratios in the blue are at the peak values they were the past two years.
2021-09-27 The instrument CCD is cold. IOL ratios are showing a very slow improvement in the bluest orders, still at low but acceptable levels. IOL ratios in the blue are at the peak values they were the past two years.
2021-09-20 The instrument CCD is cold. IOL ratios are showing a very slow improvement in the bluest orders, still at low but acceptable levels.
2021-09-18 The instrument CCD is cold. IOL ratios are showing a very slow improvement in the bluest orders, still at low but acceptable levels.
2021-09-13: The instrument CCD is cold. IOL ratios are showing a very slow improvement in the bluest orders, still at low but acceptable levels.
2021-09-06: The instrument CCD is cold. IOL ratios are showing a very slow improvement in the bluest orders, still at low but acceptable levels.
2021-08-30: The instrument CCD is cold. IOL ratios are showing a very slow improvement in the bluest orders, still at low but acceptable levels.
2021-08-09: The instrument CCD is cold. IOL ratios are showing a very slow improvement in the bluest orders, still at low but acceptable levels.
2021-08-02: The instrument CCD is cold. IOL ratios are showing a very slow improvement in the bluest orders, still at low but acceptable levels.
2021-07-26: The instrument CCD is cold. IOL ratios have leveled off some but at a slightly higher level, still at low but acceptable levels.
2021-07-12: The instrument CCD is cold. IOL ratios have leveled off at low but acceptable levels.
2021-07-06: The instrument CCD is cold. IOL ratios have leveled off at low but acceptable levels.
2021-06-28: The instrument CCD is cold. IOL ratios are leveling off at low but acceptable levels.
2021-05-24: The instrument CCD is cold. IOL ratios have been steadily dropping over the past week.
2021-05-18: The instrument CCD is cold. IOL ratios will be monitored over the next few days more often to see if contamination returns.
2021-05-17: The instrument remains unavailable while we have the CCD warmed and the shield cold. We are attempting to increase the IOL ratio.
2021-05-14: IOL ratios dropped dangerously low over the past 48 hours. Attempting to correct by warming the CCD reservoir but keeping the shield cold. We have not decided at this time if to put it back on a vacuum pump.
2021-05-12: Instrument is available and operating nominally at this time.
2021-05-11: Completed instrument vacuum maintenance. Installed new vacuum valve and ion pump . Instrument should be cold by tomorrow morning.
2021-05-04: Instrument is undergoing normal maintenance
2021-04-19: Instrument has been operating nominally.
2021-04-12: Instrument has been operating nominally.
2021-04-05: Instrument has been operating nominally.
2021-03-29: Instrument has been operating nominally.
2021-03-07: Installed a new Thorium Argon (ThAr) bulb to replace a weakening bulb in the bluest orders.
2021-02-25: The instrument was using an unusal amount of LN2 and there were temperature spikes during fills. We tracked it down to a popped pressure relief valve. Reseated, the instrument is performing nominally now.
2021-02-22: The instrument is operating nominally.
2021-02-15: The instrument is operating nominally.
2021-02-08: The instrument is operating nominally.
2021-02-01: The instrument is operating nominally.
2021-01-25: The instrument is operating nominally. IOL continues to slowly improve with colder ambient temperatures.
2021-01-18: The instrument is operating nominally. IOL continues to slowly improve with colder ambient temperatures.
2021-01-11: The instrument is operating nominally. IOL continues to slowly improve with colder ambient temperatures.
2021: Most recent interorder ratio plot can be found here.
2021-01-05: The instrument is operating nominally. IOL continues to slowly improve with colder ambient temperatures.

ARCTIC

2021-10-11: Instrument is operating nominally. For those using the new diffuser interface in TUI, the command "arctic status" may be needed to update your window after changing instrument configurations. We are looking into a soultion. The diffuser upgrades are available in 2.6.1a2 and later.
2021-10-04: Instrument is operating nominally.
2021-09-27: Instrument is operating nominally.
2021-09-20: Instrument is operating nominally.
2021-09-18: Instrument is operating nominally. Software modifications are complete. All new functions (instrument cover status, true in/out status, RPM good status, rotation control, in/out control) of the new duffuser are available. If you request use of the diffuser please send an email to the Telescope Engineer or Observing Specialists for instructions on how to patch your TUI for the controls. Changes will be released in a new TUI with KOSMOS TUI release.
2021-09-16: Instrument is operating nominally. Software modifications are complete. All new functions (instrument cover status, true in/out status, RPM good status, rotation control, in/out control) of the new duffuser are available.
2021-09-13: Instrument is operating nominally. Installed diffuser modifications (hardware and electronics) last week. Software modifications are still on going. Diffuser can be used in/out only at this time. Rotation is not functional even after the upgrade.
2021-09-06: Instrument is operating nominally. Installed diffuser modifications (hardware and electronics) last week. Software modifications are still on going. Diffuser can be used in/out only at this time. Rotation is not functional even after the upgrade.
2021-08-30: Instrument is operating nominally. Installed diffuser modifications (hardware and electronics) last week. Software modifications are still on going. Diffuser can be used in/out only at this time. Rotation is not functional even after the upgrade.
2021-08-09: Instrument is operating nominally. Moved the ionpump to the gamma vacuum controller (off of the varian controller).
2021-08-02: Instrument is operating nominally.
2021-07-27: Instrument is operating nominally.
2021-07-13: Instrument is shutdown for annual maintenance.
2021-07-12: Instrument is operating nominally. Ion pump currents are elevated but still in operating range. Instrument servicing begins tomorrow.
2021-07-06: Instrument is operating nominally. Ion pump currents are elevated but still in operating range.
2021-06-28: Instrument is operating nominally. Ion pump currents are elevated but still in operating range.
2021-05-24: Instrument is operating nominally. Ion pump currents are elevated but still in operating range.
2021-05-17: Instrument is operating nominally.
2021-05-11: Instrument is operating nominally.
2021-05-04: Instrument is operating nominally.
2021-04-21: While installing the diffuser upgrade we ran into a few interference and balance issues that may require some time to fix. While attempting to reinstall the diffuser optic back in original diffuser table the retaining ring became jammed. Until we can remove the optic from the new table and install back in the original table the robotics needs to remain powered down and the instrument is unavailable.
2021-04-19: The instrument is operating nominally.
2021-04-12: The instrument is operating nominally.
2021-04-05: The instrument is operating nominally. The diffuser in/out motion has been repaired and no longer requires rotating the instrument for gravity assist.
2021-03-29: The instrument is operating nominally. The diffuser in/out motion has required turning the instrument upside down/ or zero rotation respectably for gravity assist. Investigating the problem.
2021-02-22: The instrument is operating nominally. Users are reminded at ambient temperatures below -10C the shutter becomes unreliable and sticks open/shut. Please inspect your data carefully and report any issue found. There is a manual reset that the observing specialist can activate.
2021-02-15: The instrument is operating nominally. Users are reminded at ambient temperatures below -10C the shutter becomes unreliable and sticks open/shut. Please inspect your data carefully and report any issue found. There is a manual reset that the observing specialist can activate.
2021-02-08: The instrument is operating nominally. Users are reminded at ambient temperatures below -10C the shutter becomes unreliable and sticks open/shut. Please inspect your data carefully and report any issue found. There is a manual reset that the observing specialist can activate.
2021-02-01: The instrument is operating nominally. Users are reminded at ambient temperatures below -10C the shutter becomes unreliable and sticks open/shut. Please inspect your data carefully and report any issue found. There is a manual reset that the observing specialist can activate.
2021-01-25: The instrument is operating nominally. Users are reminded at ambient temperatures below -10C the shutter becomes unreliable and sticks open/shut. Please inspect your data carefully and report any issue found. There is a manual reset that the observing specialist can activate.
2021-01-18: The instrument is operating nominally. Users are reminded at ambient temperatures below -10C the shutter becomes unreliable and sticks open/shut. Please inspect your data carefully and report any issue found. There is a manual reset that the observing specialist can activate.
2021-01-11: The instrument is operating nominally. Users are reminded at ambient temperatures below -10C the shutter becomes unreliable and sticks open/shut. Please inspect your data carefully and report any issue found. There is a manual reset that the observing specialist can activate.
2021: APO does not recommend taking dome flats with ARCTIC. We are working on designing a supplemental baffle to correct the problem with cover flats. Currently cover flats produce a gradient across the flat field that is dependant on telescope position (altitude) and rotator angle.
2021-01-05: The instrument is operating nominally. Users are reminded at ambient temperatures below -10C the shutter becomes unreliable and sticks open/shut. Please inspect your data carefully and report any issue found. There is a manual reset that the observing specialist can activate.

DIS

2021-10-11: Vacuum servicing of red camera in progress. The instrument is not available at this time.
2021-10-08: Vacuum servicing of red camera started today. Warmed. Replaced ion pump. Put on vacuum pump.
2021-10-04: Blue contamination is still poor.
2021-09-27: Blue contamination is slowly improving.
2021-09-20: Cooled down blue camera. Contamination for blue looks far worse than when we started. The next few days will tell if it improves.
2021-09-18: Started vacuum serving of Blue camera. Instrument is not available during servicing.
2021-09-18: Started vacuum serving of Blue camera. Instrument is not available during servicing.
2021-09-16: Attempted to start DIS Blue vaccum servicing however ran out of time in the evening before start of observations due to techincal problems with vacuum pumping station.
2021-09-13: Recent measurements show both red and blue cameras have significantly worse performance with regard to contamination. Instrument is still usable but much light is scattered into the wings of the psf for both cameras.
2021-09-06: Recent measurements show both red and blue cameras have significantly worse performance with regard to contamination. Instrument is still usable but much light is scattered into the wings of the psf for both cameras.
2021-08-30: Recent measurements show both red and blue cameras have significantly worse performance with regard to contamination. Instrument is still usable but much light is scattered into the wings of the psf for both cameras.
2021-08-09: Recent measurements show both red and blue cameras are showing somewhat worse performance with regard to contamination. Instrument is still usable. The cryotiger for the RED camera died Friday. It was replaced with a new compressor. Today a power brownout caused the BLUE cryotiger to hiccup and have a partial warmup. It is recovering from the partial warmup. Placed the BLUE ionpump on the old blue varian controller this afternoon (off the gamma vacuum controller).
2021-08-02: Recent measurements show both red and blue cameras are showing somewhat worse performance with regard to contamination. Instrument is still usable.
2021-07-27: Recent measurements show both red and blue cameras are showing somewhat worse performance with regard to contamination. Instrument is still usable.
2021-07-12: Recent measurements show both red and blue cameras are showing good to excellent performance with regard to contamination.
2021-07-05: Red camera had a partial inadvertant warmup yesterday. Restored cooling. Russet checked pinhole images and determined both red and blue cameras are showing good to excellent performance with regard to contamination.
2021-06-28: Both red and blue cameras are showing good to excellent performance with regard to contamination. The red camera is running unseasonably warm as well.
2021-05-24: Both red and blue cameras are showing good to excellent performance with regard to contamination. The red camera is running unseasonably warm as well.
2021-05-17: Both red and blue cameras are showing good to excellent performance with regard to contamination. Russet does report she can now measure the contamination on both cameras. The red camera is running unseasonably warm as well.
2021-05-11: Both red and blue cameras are showing good to excellent performance with regard to contamination. Russet does report she can now measure the contamination on both cameras. The red camera is running unseasonably warm as well.
2021-05-04: Both red and blue cameras are showing good to excellent performance with regard to contamination. Russet does report she can now measure the contamination on both cameras. The red camera is running unseasonably warm as well.
2021-04-19: Both red and blue cameras are showing good to excellent performance with regard to contamination. Russet does report she can now measure the contamination on both cameras. The red camera is running unseasonably warm as well.
2021-04-12: Both red and blue cameras are showing good to excellent performance with regard to contamination. Russet does report she can now measure the contamination on both cameras. The red camera is running unseasonably warm as well.
2021-04-05: Both red and blue cameras are showing good to excellent performance with regard to contamination. Russet does report she can now measure the contamination on the red camera. The red camera is running unseasonably warm as well.
2021-03-29: Both red and blue cameras are showing good to excellent performance with regard to contamination. However Russet does report that she is seeing the beginning signs of return of contamination. The red camera is running unseasonably warm as well.
2021-02-22: Both red and blue cameras are showing good to excellent performance with regard to contamination.
2021-02-15: Both red and blue cameras are showing good to excellent performance with regard to contamination.
2021-02-08: Both red and blue cameras are showing good to excellent performance with regard to contamination.
2021-02-01: Both red and blue cameras are showing good to excellent performance with regard to contamination.
2021-01-25: Russet reports both red and blue cameras are showing good to excellent performance with regard to contamination.
2021-01-18: Russet reports both red and blue cameras are showing good to excellent performance with regard to contamination.
2021-01-11: Russet reports both red and blue cameras are showing good to excellent performance with regard to contamination.
2021-01-05: Russet reports both red and blue cameras are showing good to excellent performance with regard to contamination.

KOSMOS

2021-10-11: Compiling a punch list of daytime engineering tests, needed repairs and nice to haves after on sky testing. Instrument shutter seems to be the largest issue currently. The shutter fails around 5C. UW TEG is working on a replacement.
2021-10-04: Started on sky commissioning this past weekend. Software development is on going and there is still no TUI release. Have made instrument blocks for spectra and imaging modes. Guide camera software is not working properly and guiding still is not working. However exposures of internal cal and truss lamps were taken, first light on a few targets were performed. Some issues with the calibration stage and shutter were encountered. Those details are being worked on. Much progress has been made the past few weeks integrating to the telescope and network.
2021-09-18: The spectragraph is scheduled to be delivered Monday. Tracking shows it is in El Paso, TX this morning. Much of the next 2 weeks will be unpacking, assembly and integration into the system. On sky commissioning will follow in October.

NICFPS

2021-10-11: No change. The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-10-04: No change. The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-09-27: No change. The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-09-20: No change. The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-09-18: No change. The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-09-13: No change. The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-09-06: No change. The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-08-30: No change. The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-08-09: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-08-02: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-07-27: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-07-12: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-07-06: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-06-28: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-05-24: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-05-17: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-05-11: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-05-04: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-04-19: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-04-12: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events. Additionally we have seen an increase in the times the active port on the terminal server that services the robotics has locked up. Cause is unknown but if recognized immediately the fix is just a few minutes.
2021-04-05: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-03-29: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-02-22: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-02-15: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-02-08: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-02-01: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-01-25: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-01-18: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-01-11: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2021-01-05: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images. These have been seen most often when the instrument is upside down. You may asked to rotate your field 180 degrees to minimize these events.
2020-08-17: The instrument is operating nominally however the users should be on the lookout for corrupted images. This is still occuring intermittently and not well understood. Report any corrupted images to the observing specialist so they can reset the array electronics.

TRIPLESPEC

2021-10-11: The instrument is operating nominally. There still is some reported low level pattern noise seen in long darks or images.
2021-10-04: The instrument is operating nominally. There still is some reported low level pattern noise seen in long darks or images.
2021-09-27: The instrument is operating nominally. There still is some reported low level pattern noise seen in long darks or images.
2021-09-20: The instrument is operating nominally. There still is some reported low level pattern noise seen in long darks or images.
2021-09-18: The instrument is operating nominally. There still is some reported low level pattern noise seen in long darks or images.
2021-09-13: The instrument is operating nominally. There still is some reported low level pattern noise seen in long darks or images.
2021-09-06: The instrument is operating nominally. There still is some reported low level pattern noise seen in long darks or images.
2021-08-30: The instrument is operating nominally. There still is some reported low level pattern noise seen in long darks or images.
2021-08-17: The instrument is operating nominally. A clock driver board was replaced (after a new one was purchased). This corrected the corrupted images. There still is some low level pattern noise seen in long darks or images.
2021-08-09: The observing specialists reported corrupted images on Thursday night. We tried to troubleshoot and images became all zeros. Today we attempted multiple reboots and restarts of the software as well as powercycles of the main array controller. We attempted a swap of the PCI card but the problem remained. The instument is unusable for tonight. Will try further troubleshooting tomorrow.
2021-08-02: The instrument is operating nominally.
2021-07-27: The instrument is operating nominally.
2021-07-12: The instrument is operating nominally.
2021-07-06: The instrument is operating nominally.
2021-06-28: The instrument is operating nominally.
2021-05-24: The instrument is operating nominally.
2021-05-17: The instrument is operating nominally.
2021-05-11: The instrument is operating nominally.
2021-05-04: The instrument is operating nominally.
2021-04-19: The instrument is operating nominally.
2021-04-12: The instrument is operating nominally.
2021-04-05: The instrument is operating nominally.
2021-03-29: The instrument is operating nominally.
2021-02-22: The instrument is operating nominally.
2021-02-15: The instrument is operating nominally.
2021-02-01: No change in the instrument status. There still appears to be a low level pattern noise in some images. From David Decolibus: "the low-level pattern noise can be effectively avoided just by keeping the instrument upright (between -90 and +90 mount). In the twelve nights of observing I've had (beginning in September), I have not seen the pattern noise in *any* data in which I have kept the instrument upright. A few exposures below the horizontal (like for a standard star) is fine, but keeping the instrument inverted for an extended period seems to introduce the pattern noise. Last night, I wasn't paying attention and the slit angle I chose was about 30 degrees below the horizontal (-120 mount) for about 30 minutes. I started to see the pattern noise on the last few frames of this data. As soon as I rotated the slit 180 degrees, the noise went away, which only confirms my suspicions that it is strongly correlated with instrument rotator position."
2021-02-01: No change in the instrument status. There still appears to be a low level pattern noise in some images. From David Decolibus: "the low-level pattern noise can be effectively avoided just by keeping the instrument upright (between -90 and +90 mount). In the twelve nights of observing I've had (beginning in September), I have not seen the pattern noise in *any* data in which I have kept the instrument upright. A few exposures below the horizontal (like for a standard star) is fine, but keeping the instrument inverted for an extended period seems to introduce the pattern noise. Last night, I wasn't paying attention and the slit angle I chose was about 30 degrees below the horizontal (-120 mount) for about 30 minutes. I started to see the pattern noise on the last few frames of this data. As soon as I rotated the slit 180 degrees, the noise went away, which only confirms my suspicions that it is strongly correlated with instrument rotator position."
2021-02-01: No change in the instrument status. There still appears to be a low level pattern noise in some images. From David Decolibus: "the low-level pattern noise can be effectively avoided just by keeping the instrument upright (between -90 and +90 mount). In the twelve nights of observing I've had (beginning in September), I have not seen the pattern noise in *any* data in which I have kept the instrument upright. A few exposures below the horizontal (like for a standard star) is fine, but keeping the instrument inverted for an extended period seems to introduce the pattern noise. Last night, I wasn't paying attention and the slit angle I chose was about 30 degrees below the horizontal (-120 mount) for about 30 minutes. I started to see the pattern noise on the last few frames of this data. As soon as I rotated the slit 180 degrees, the noise went away, which only confirms my suspicions that it is strongly correlated with instrument rotator position."
2021-01-25: No change in the instrument status. There still appears to be a low level pattern noise in some images. From David Decolibus: "the low-level pattern noise can be effectively avoided just by keeping the instrument upright (between -90 and +90 mount). In the twelve nights of observing I've had (beginning in September), I have not seen the pattern noise in *any* data in which I have kept the instrument upright. A few exposures below the horizontal (like for a standard star) is fine, but keeping the instrument inverted for an extended period seems to introduce the pattern noise. Last night, I wasn't paying attention and the slit angle I chose was about 30 degrees below the horizontal (-120 mount) for about 30 minutes. I started to see the pattern noise on the last few frames of this data. As soon as I rotated the slit 180 degrees, the noise went away, which only confirms my suspicions that it is strongly correlated with instrument rotator position."
2021-01-18: No change in the instrument status. There still appears to be a low level pattern noise in some images. From David Decolibus: "the low-level pattern noise can be effectively avoided just by keeping the instrument upright (between -90 and +90 mount). In the twelve nights of observing I've had (beginning in September), I have not seen the pattern noise in *any* data in which I have kept the instrument upright. A few exposures below the horizontal (like for a standard star) is fine, but keeping the instrument inverted for an extended period seems to introduce the pattern noise. Last night, I wasn't paying attention and the slit angle I chose was about 30 degrees below the horizontal (-120 mount) for about 30 minutes. I started to see the pattern noise on the last few frames of this data. As soon as I rotated the slit 180 degrees, the noise went away, which only confirms my suspicions that it is strongly correlated with instrument rotator position."
2021-01-11: No change in the instrument status. There still appears to be a low level pattern noise in some images. From David Decolibus: "the low-level pattern noise can be effectively avoided just by keeping the instrument upright (between -90 and +90 mount). In the twelve nights of observing I've had (beginning in September), I have not seen the pattern noise in *any* data in which I have kept the instrument upright. A few exposures below the horizontal (like for a standard star) is fine, but keeping the instrument inverted for an extended period seems to introduce the pattern noise. Last night, I wasn't paying attention and the slit angle I chose was about 30 degrees below the horizontal (-120 mount) for about 30 minutes. I started to see the pattern noise on the last few frames of this data. As soon as I rotated the slit 180 degrees, the noise went away, which only confirms my suspicions that it is strongly correlated with instrument rotator position."
2021-01-05: No change in the instrument status. There still appears to be a low level pattern noise in some images. From David Decolibus: "the low-level pattern noise can be effectively avoided just by keeping the instrument upright (between -90 and +90 mount). In the twelve nights of observing I've had (beginning in September), I have not seen the pattern noise in *any* data in which I have kept the instrument upright. A few exposures below the horizontal (like for a standard star) is fine, but keeping the instrument inverted for an extended period seems to introduce the pattern noise. Last night, I wasn't paying attention and the slit angle I chose was about 30 degrees below the horizontal (-120 mount) for about 30 minutes. I started to see the pattern noise on the last few frames of this data. As soon as I rotated the slit 180 degrees, the noise went away, which only confirms my suspicions that it is strongly correlated with instrument rotator position."

MISC

NA2 GUIDER

2021-10-11: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-10-04: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-09-27: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-09-20: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-09-18: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-09-13: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-09-06: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-08-09: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-08-02: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-07-27: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-07-12: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-07-06: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-06-28: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-05-24: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-05-17: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-05-11: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-05-04: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-04-19: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-04-12: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-04-05: The instrument is operating nominally. It is still requiring nearly daily or multiple resets of the USB with a nub restart.
2021-03-29: The instrument is operating nominally.
2021-02-22: The instrument is operating nominally.
2021-02-15: The instrument is operating nominally.
2021-02-08: The instrument is operating nominally.
2021-02-01: The instrument had some issues at the end of December, we believe we have tracked the problem down to a loose power cord on the instrument control computer.
2021-01-25: The instrument had some issues at the end of December, we believe we have tracked the problem down to a loose power cord on the instrument control computer.
2021-01-18: The instrument had some issues at the end of December, we believe we have tracked the problem down to a loose power cord on the instrument control computer.
2021-01-11: The instrument had some issues at the end of December, we believe we have tracked the problem down to a loose power cord on the instrument control computer.
2021-01-05: The instrument had some issues at the end of December, we believe we have tracked the problem down to a loose power cord on the instrument control computer.

Apache Point Observatory New Mexico, USA

ARC 3.5-m Instrument News

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Current Status

The information on this page is up to date as of October 11, 2021. This page is maintained by the 3.5-m Telescope Engineer .

Apache Point Observatory
New Mexico, USA