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09272018

Nightly Observing Plan for MJD 58389 (starting evening of September 27, 2018)

DES has the full night.

Observers

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

CTIO Staff

Almanac

mjd 58389, date 20180927, Site CTIO, UT-offset 3 hr
Current local time 16:29 CLST     UT 19:29     SidTim 15:12
Event      Local-Time  Greenwich  Sidereal-Time
Sunset     19:49 CLST  22:49 UT   18:32  278 deg  
Eve. -10   20:24 CLST  23:24 UT   19:07  287 deg  Zeropoint; standards
Eve. -14   20:43 CLST  23:43 UT   19:26  292 deg  Begin obstac
Eve. -18   21:02 CLST  00:02 UT   19:45  296 deg  Last chance standards
Moonrise   22:16 CLST  01:16 UT   21:00  315 deg  
Midpoint   01:33 CLST  04:33 UT   00:17    4 deg  
Morn -18   06:05 CLST  09:05 UT   04:49   72 deg  Begin astronomical twilight
Morn -14   06:23 CLST  09:23 UT   05:07   77 deg  End obstac; begin standards
Morn -10   06:43 CLST  09:43 UT   05:27   82 deg  
Sunrise    07:18 CLST  10:18 UT   06:02   90 deg  
Moon position (deg): RA 41.3, Dec 11.1 Phase: 0.807

Weather Conditions

Observing Plan and Goals for the Night

  • DES full night
  • Standards
Standards for evening twilight

UT Date = '2018/09/27 23:24'     Local time = 20:24
SDSSJ2140-0000        ra 21:40:00  dec +00:00:00  secz 1.5
E8-A                  ra 20:07:22  dec -44:37:01  secz 1.1
  • 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 
UT Date = '2018/09/28 09:23'     Local time = 06:23
SDSSJ0843-0000        ra 08:43:00  dec +00:00:00  secz 1.9
E4-A                  ra 09:23:44  dec -45:21:02  secz 1.6
C26202/HST            ra 03:32:30  dec -27:46:05  secz 1.1

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".

Plan:

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/photosweep.sh 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 http://des-ops.fnal.gov:8080/prednight/ .
  • 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.