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Devon Hollowood, 09/28/2018 02:29 PM


Nightly Observing Plan for MJD 58390 (starting evening of September 28, 2018)

DES has the second half of the night.


  • Erika Wagoner (observer 1)
  • Anqi Chen (observer 2)
  • Devon Hollwoood (Run Manager)

CTIO Staff


Weather Conditions

Observing Plan and Goals for the Night

  • DES full night
  • Standards
  • If clouds remain, run DECal
Standards for evening twilight

  • Obstac as long as seeing is < 1.6 arcsec
  • If bad seeing (1.6 arcsec < seeing < 2.0) and clear: Photosweeps
  • If bad seeing (seeing > 1.6 arcsec) and not clear, or very bad seeing (seeing > 2.0 arcsec): Narrowband (X3 or C3)
  • If seeing good but cloudy: obstac
  • Call Eric if there are problems
  • Morning standards (if clear) [grizY ordered scripts]:
Standards for morning twilight 

Useful links

Nightsum | CTIO Night Report | DECam Logbook
Tololo Environmental Web Page | Detailed hourly forecast | Satellite maps

Notes from (yesterday's) 4PM Meeting

Other Notes

Detailed plan for bad seeing:

  • Run Obstac if not bad seeing.
  • Start w/ gr for a very little while, then zY, then only Y

Definition of "Bad Seeing":

If the PSF projected to i-band @ zenith > 1.1", Obstac will be queueing g-band exposures close to zenith (Y-band if it's Moony). The PSF isn't as good with g-band as the other filters. Use the KentOols report to watch the seeing on indvidual exposures if we get PSF > 1.6" for several in a row and there isn't any obvious likelihood of improvement to better than 1.6" in the next 10 minutes then we call the time "bad seeing".


Tonight if the conditions reach "bad seeing" we do either "photosweep" or "narrow band" scripts. Photosweep has higher priority than "narrowband". If "Bad Seeing" and photometric and not worse than 2.0" => Photosweep. If "Bad Seeing" and not photometric, then do narrowband.

Observers generate the photo-z jsons run the photo-z script. It's at /usr/remote/user/sispi/y6_global_photometry_program/ with names like: photosweep20180914-2200Z.json Select the one with timestamp closest to the next top of hour, now in UT (we got the z added).

  • Do not bother with this is there's < 30 minutes left in the night.
  • Do not bother with this program if clouds are visible on Rasicam.
  • Require Bad Seeing, but PSF <2 arcsec. If seeing is worse or highly variable,
    the varying aperture corrections make it difficult to get to mmag accuracy. Probably they take an hour.
  • Narrowband scripts are in the directory: /usr/remote/user/DECamObserver/ExposureScripts/DES_scripts
  • Names like SN-C3X-N964.json
  • Information about the transit time of thse fields can be found at .
  • They are on the SN fields, so select the field that is closest to transit.
  • These are expected to be about an hour long. If the clouds are only moderate, we could do these.