UT 26 Aug 2020 - Night #5 of Restart

OSA: S. Allanson

ISp: E. Solheid

Mtn Manager: L. Durham

ISA: O. Kuhn (Tucson)


  1. Lost at least an hour or more due to /newdata running out of space. For future, even during restart, IA2 is strongly encouraged not to move data in/out of /newdata during nighttime operations.
  2. Spot seen on LBC-R (r-sloan) but seems to have vanished during skyflats - check filters or lenses?
  3. IT 6386 - MODS2B Sequencer - all sievesnaps at start of night affected, but seems to have abated durng on-sky - need to check exposures to verify it did not return. Has occurred of night each night.


  • MODS
    • Basic Checkout
      • Observe a standard star in all modes (30-45 min for 3 images).
        • Repeat if clear, otherwise take specstd for any modes used during the night
      • Dice-5 imaging offsets
        • Dumbell Nebula (first half)
        • M76 (2nd half)
    • Test Science OB
      • Sidereal
      • Non-Sidereal
    • Spectrophotometric standards (only if clear)
  • LBC- Red
    • DOFPIA / doHybrid - colliimatie on sky
    • Test Images
    • Rotator Center
  • Mixed mode MODS-1/LBC-Red tests
  • LUCI-2 (if released for on-sky)
    • Dectector Rotator
    • Rotator ZP (Longslit method - see OT and J.Power's notes)
    • Imaging Dither Test


We obtained sufficient data to release MODS for science and got a start with LBCR.

We started with binocular MODS, and:
  • observed a spectrophotometric standard,
  • a science-like imaging sequence,
    • with async 45", 45" dithers (which required turning off the copointing check but ran well, save for one trailed pair of images
    • with sync offsets instead (which failed on at least two occasions when the asynchronicity between the 2 MODS exceeded the 60-sec timeout; see existing IT 6939. These observations only confirmed the recommendation not to use syncoffsets in imaging scripts.
  • ran a dithering sequence with the pointing mask to check the alignment of the DETXY coordinate system and mask
  • ran a long-slit observation (of PN NGC40).
  • observed a NS target
  • and then, as it appeared clear on the all-sky and the guide flux was stable (but note that there was significant haze! not to mention the many clouds earlier in the night), we
    • observed an photometric field in dual, blue and red-only imaging modes
    • observed a second standard star in all modes
Around 10:30 UT, we reconfigured MODS2-> LBCR and started to checkout LBCR with:
  • superfoc sequences
  • data to measure the rotator center
  • a science-like OB that dithered and guided


We had a few issues:

MODS2B --- the first 7(!) sieveSnaps showed evidence of sequencer issues, but the remaining 80+ images were all good. IT 6836

newdata -- filled up during the night, a consequence of the work to resolve data flow to Repository (IT 8160)

The LBCR images through at least 3 filters showed a spot near the rotator center, but when I took sky flats through these same filters, and more, I saw no such spot. Was it a transient moth on the dewar window that flew away when we slewed? We observed 3 fields - I'll have to compare, but the sky flats show no evidence of dust or debris on the dewar or filters used (R, r, i, z, Y, F).


Times are in UT.

01:35 Ran up both MODS, woke them and took sieveSnap images. modsNc.20200826

First 5 mods2b images affected by sequencer issues. 0/5 good images.

01:45 Powered off/on HEB and did a quit,"ic" on m2.bc

01:50 Another two sieveSnaps 0006 and 0007 Again the mods2b images are bad.

02:09 Twilight sky flats on blank field 16+55:
  • Dual
  • 1K test, 0008. 1-sec at g and r. m1r: 15k, m1b
  • execMODS --modsN -e gr_skyflat_obs.txt
    • 3K @ gr 0009-13
  • execMODS --modsN -e gi(2)_skyflat_obs.txt
    • 3K @ gi 0014-
    • some stars are appearing on this set, but the flats are dithered.
  • Note - on the flats, mods2b is not showing the sequencer issue, but it can be hard to pull out of the flat field as we have seen recently for mods1r.
02:33 Going to the spectrophotometric standard, BD+33
  • Collimation/focus:
    • GCS is unable to write to Repository, IT 8169
    • Steve called Igor who is calling David E. They are working on it.
03:19 Steve is closing, since the 25-mic particle count went up above the closing limit.

03:35 Igor called back and said that David was able to reset permissions. We are testing it.
  • First, gcsclient readGuideCam left -e 1000
    • image appears in /lbt/data/share/tcs/lbto.20200826/left_guider00001.fits
    • but the image taken this way doesn't go to Repository
  • Second, Steve sent a test preset. It worked! David added a note to IT 8169 - sounds like he has resolved the problem for now, but more investigation is needed into why the NFS mounted Repository.
03:40 Steve is opening again. There are clouds, but all but sub-micron particulate counts are below their respective thresholds.

03:54 Back to BD+33:
  • Collimation/focus
  • acqBinoMODS bd332642.acq (19)
  • offsets made:
    • mods1: -0.699 11.748 rel
    • mods2: 3.434 8.282 rel
  • confirmatory thru-slit (20) look ok but a tad to the right
    • tweak using modsAlign - r on 0020
      • mods1: -0.312 0.104
      • mods2: -0223 -0.295
    • confirmatory thru-slit (21) looks better, but still the star is a bit right of center. Guide star is faint, ~15, and we have clouds and moonlight - perhaps this is a guiding issue?
  • execBInoMODS bd332642.obs
    • We are looking through clouds. Seeing is good, 0.77" on the guider.
    • So far, so good with the MODS2B. The only bad images were the first 7, all sieveSnaps.
    • < ~09:54-09:55MST lost guiding. On Dual Prism.
    • 10:01 - lost guiding again.
05:19 5-pt dither imaging script with offsets test, active mode:
  • execBinoMODS Dumbell_Nebula_Img_active.txt
    • 0.5" seeing
    • Error copointing limit 45", 45". Aborted.
    • Steve disabled the copointing check and we are repeating the script. It is working fine.
    • clouds causing the guide star to fade in and out. 05:45
      • mods1: after one offset, the offsetxy command timed out after 60-sec. Retry resumed but next image is streaked, mods1r 0039 and mods1b 0036.
      • mods2, at same time, slightly different error msg: no guide star found. Retry was ok for that side.
05:45 Repeat script but this time with syncoffset before each offset command. Let's see how things go as the 2 MODS get out of sync... We got a timeout error

execBinoMODS Dumbell_Nebula_Imct_sync.txt

MODS2 errors: bc syncoffset offsetxy 45 -45 absError: Command 'OFFSETXY 45 -45 abs' timed out after 60 secAbort, Retry, or Ignore? rRetrying command 'OFFSETXY 45 -45 absOFFSETXY 45 -45 abs

But I think that led to a stray sync flag

We had another timeout error on MODS2 on the offsetxy -45 45 abs

06:22 Longslit observation of PN NGC40
  • acquisition
    • MODS1: 49 & 50, offsetxy -0.606 10.970 rel
    • MODS2: 50 & 51, offsetxy 3.913 7.314 rel
  • execBinoMODS NGC40.obs
06:35 We ran out of disk space in newdata. Barry called Igor. Meanwhile, we continued taking spectra which appeared in modsNdata but only one (mods1r.20200826.0052.fits) in newdata.

06:55 Clouds - it's very overcast. Steve reports that he cannot see stars.

07:00 Igor made a new directory on Repository in which to temp store the files in newdata.

07:40 Newdata has more room now and we are moving on. NS target has a name that is not coming up in the NSIGUI (P29/Schwassmann-Wachmann 1), so we're doing something else while searching for alternate names.

07:45 M52 dither with pointing mask (to measure DETXY alignment with respect to mask alignment).

07:59 blue fitsflush

08:15 ~20 on each channel

08:15 NS test on Comet 29P/Schlassmann-Wachmann 1
  • execBInoMODS comet.img.txt
    • some scattered light from nearby star
    • guiding and WFSing is OK
08:45 Photometric Imaging field L92 in Strip82. It is not strictly photometric, but it is clear.
  • execBinoMODS L92dualim.txt
  • execBinoMODS L92redim.txt
  • execBinoMODS L92blueim.txt
09:20 Spectrophot Std Feige110
  • mods1r 86: -1.026 11.944
  • mods2r 90: 3.277 7.966
  • confirmatory images again to right. m1r by -0.16 and m2r by -0.4
  • observation: execBInoMODS feige110.obs
10:30-10:45 Reconfigured from MODS -> LBCR

10:45 Slewed to M76 for focus/collimation. That took a long time - 8 iterations. Seeing is very good and stable, but there was coma (z8) that WRS did not remove and the first 2 FPIA iterations were on focus only, giving -15276, then 9788. Then it added 2344 nm z8.

11:12 Superfoc
  • PA=0
  • PA=180
  • PA=0
  • Near the rotator center, there is a dust spot. (r-SLOAN)
11:29 Rotator Center measurement at 1h50d field
  • PA=0, 180, 90 and then 270
11:40 Science-like exposure
  • ptautoadjust (I forgot to collimate, but we had not moved far and collimation looks good)
  • run series of dithered, guided exposures at z, i and R.
  • In all of the LBCR images so far, taken through 4 different filters (r, z, i and R), there appears to be a spot near the rotator center.
12:06 Sky flats (although we'll need to clean the dewar window for real flats)
  • i-SLOAN: skyB~16 - bit dark still.
    • starting these at 12:17 or so and using 3-sec. The i-SLOAN flats don't show the dark ring... 121654.
  • r-SLOAN 12:19 skyB~14.5, 1-sec. The spot is gone here too...
  • R-Bessell - one flat below saturation but the spot appears to be gone
  • Y - 10k counts at 12:30, no spots
  • F972N20 - newdata filled up again. I continued the script, but will have to look for the flats later or on the PC.
12:38 Steve is closing up.
  • I turned off the LBCR (LBCB was OFF)
  • I put both MODS to sleep.

-- BarryRothberg - 25 Aug 2020
Topic revision: r9 - 26 Aug 2020, BarryRothberg
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