MAPS - Minnesota Automated Plate Scanner Catalog of the POSS I


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'standards' Table Parameters

The 'standards' database table stores information describing standard stars used to establish the 'stellar' magnitude photometric fits for each POSS I plate in the MAPS Catalog. The following parameters are stored for each photometric standard used in the MAPS Catalog:

Field Name Definition
possfield MAPS POSS I Field Name
possnumber MAPS POSS I Field Number
objectname The full MAPS Catalog object corresponding to this photometric standard when available. Otherwise, two other kinds of "names" may be provided:
  • A "hyphen" means this standard was never used for photometric calibration.
  • An entry in the form "Ostarnum" or "Estarnum" means that this was an "unrecovered" standard. A standard can be "unrecovered" because the photometric calibration occurs before the final matching between O and E plate images occurs. In some cases a standard was unmatched or the starnumber changed and the original standard could no longer be definatively identified.
standard The names of the standards indicate where data was obtained.
  • gsc: Guide Star Catalog
  • cap: Capilla Peak CCD Photometry
  • ctio: Cerro Tololo CCD Photometry
  • kpno: Kitt Peak CCD Photometry
  • maj: Majewski pre-publication CCD Photometry (only on P323)
  • mcd: McDonald CCD Photometry
Vmag, Verr, BVmag, BVerr, VRmag, VRerr The standards' V, B-V, and V-R magnitude/colors and their respective errors. Note that for Guide Star Catalog standards, the reported V-R magnitudes come from applying a transformation from V and B-V to B-R based on Landolt standards as described in Larsen (1996) and Larsen (2003).
night The night the observation was made, if known
Odia, Edia The "areal" diameter (in EREs) of this object from the O and E plate scans respectively (By "areal" diameter, we mean the diameter determined by taking the surface area of the scanned object in square EREs, and then computing the diameter of a circle with the same area.).
Omag, Emag The O and E magnitudes of the objects, respectively, computed from B,V,R magnitudes using standard transformations. These are NOT necessarily the final magnitude recorded in the MAP Catalog.
Oerr, Eerr The O and E magniude uncertainties, respectively.
Oresid, Eresid The residuals of the O and E magnitudes, respectively, to the diameter-magnitude function fit.
used Records whether the star was used in the final fit of the diameter-magnitude relation on both plates (OE), the O plate only (O), the E plate only (E), or neither (N).