Observing at WMKO - Planning
Starlist File Format


Your starlist file contains the list of targets you plan to observe during the night at Keck. The file must conform to certain formatting rules described below in order for the telescope control software to read the file properly. There are additional requirements for Adaptive Optics target lists.

Formatting Rules for General Target Lists

General Rules

Required Fields

Optional Fields

The following fields are identified by the form keyword=value.

Important Note: no spaces are allowed around either side of the equals sign, nor within the keywords or values themselves. Essentially, if there is a "word" consisting of a string of letters, there must be an "=" sign somewhere within that string to designate the keyword and value separation.

Starlist Keywords
Property Keyword Units or Values
RA proper motion pmra=s.ssss seconds-of-time/year
Dec proper motion pmdec=a.aaa arcsec/year
RA differential tracking rate dra=s.ssss arcsec/hr divided by 15 (positive implies moving east)
Dec differential tracking rate ddec=a.aaa arcsec/hr
V magnitude vmag=m.m mag
Rotator mode rotmode=nnn pa, vertical, or stationary (see note below about vertical angle mode)
Rotator position angle rotdest=mmm.mm degrees
Telescope azimuth wrap wrap=xxx shortest, south, or north (south is clockwise with az increasing and north is counterclockwise with az decreasing)
RA telescope offset from target RA raoffset=xx.x arcseconds (positive implies moving east)
Dec telescope offset from target Dec decoffset=xx.x arcseconds (positive implies moving north)

  • raoffset and decoffset are passive in that they fill in the fields on the OA offset GUI, but the OA must still execute the command for the telescope to move.
  • For historic reasons, if the equinox is APP, either dra/ddec or pmra/pmdec will be interpreted as differential tracking rates.
  • You may place other comments or notes at the end of the line. These will be ignored by the control software, but retained in your text file for your information.
  • Note that vertical angle (VA) mode is not available with all instruments. For many instruments (examples include LRIS, ESI) guiding in VA mode is not as good as guiding in position angle (PA) mode. In cases where VA is not supported, select PA mode, do not specify an angle, and simply ask the OA to select a PA which is near the parallactic angle at the time of your observation. This will be very similar to VA mode and will often have better guiding performance than actual VA mode, but of course the slit will rotate slightly relative to vertical angle during the observation.
  • Installing Your Starlist file

    In order for the Observing Assistant to locate your starlist file, you must install it in the “starlist directory” on our network. You can access the starlist directory /kroot/starlists from most of our computers (except certain instrument host computers). The convention we suggest is to store your starlist in a subdirectory which is named using the last name of the observing program's PI (e.g., copernicus). If needed, you can create the directory using the command

    	mkdir -p /kroot/starlists/piname
    and then install your starlist using the command
    	cp starlist /kroot/starlists/piname
    You are free to name your starlist file whatever you want.

    Note that /kroot/starlists/ is equivalent to /s/starlists/

    Sample Starlist File

    # basic objects including only required fields
    197+17.1        07 29 09.40 +20 54 45.90 2000.0
    ring neb        18 53 36.00 +33 02 00.00 2000.0
    # star with proper motion
    SAO 102961      17 34 24.13 +11 52 28.29 1950.0 pmra=+0.0001 pmdec=-0.007 vmag=9.0
    # non-sideral targets
    Hale-Bopp 5hr   17 30 6.62  -4 41 58.4   APP dra=0.35  ddec=7.3
    Titan   6:00UT  01 05 39.60 +04 00 28.846 APP dra=-0.96 ddec=-4.2
    # slitmask with specified rotator position
    Cl0024+16-fld 1 00 24 00.00 +16 00 00.00 2000.0 rotdest=123.45 rotmode=pa
    # target observed at parallactic angle
    Herschel101     12 34 56.78 +01 23 45.67 2000.0 rotdest=0.0 rotmode=vertical
    # science target with nearby offset stars
    198xq           13 55 45.78  -25 24 03.3  2000.0
    198xq_S1        13 55 46.85  -25 23 46.3  2000.0 raoffset=-14.51 decoffset=-16.99   # 14.51" W,  16.99" S to 198xq
    198xq_S2        13 55 48.26  -25 22 10.6  2000.0 raoffset=-33.61 decoffset=-112.72  # 33.61" W, 112.72" S to 198xq
    198xq_S3        13 55 39.96  -25 21 50.1  2000.0 raoffset=78.83  decoffset=-133.21  # 78.83" E, 133.21" S to 198xq

    Formatting Target Lists for AO Observations

    Further requirements exist for target lists for Laser and Natural Guidestar Adaptive Optics observations. Please see the Laser Guide Star Adaptive optics page and especially the Formatting AO Target Lists description for further details.

    This page last updated 10-Aug-2015, gm