VI/25 POSS Plate Data (Palomar Obs. 1960) ================================================================================ National Geographic Society and Palomar Observatory Sky Survey Catalogue of Plates Palomar Observatory ================================================================================ ADC_Keywords: Surveys ; Plate data Description: This catalog contains plate-center and observational data for all plates of the National Geographic Society and Palomar Observatory Sky Survey (POSS) and its Whiteoak Extension. The POSS proper consists of photographic reproductions of red-sensitive (Kodak 103a-E) and blue-sensitive (Kodak 103a-O) plates taken of 937 different fields with the 48-inch Palomar Schmidt telescope, covering the entire sky above -33 degrees declination. This southern limit was extended to about -45 degrees by J.B. Whiteoak using the same instrument for a series of 100 photographs that have come to be known as the Whiteoak Extension; thus, the survey as a whole includes 1037 fields. This version of the catalogue consists of plate information reproduced from the Catalogue of Plates and plate information on the Whiteoak Extension derived from file headers of the SAOPSS II tape (Lund and Dixon 1973). The fields of the catalog are POSS number, modified Luyten-Palomar (MLP) number, equatorial coordinates of the plate center (B1950), limits of the right ascension on the plate in radians, galactic coordinate of the plate center, number of SAO stars on the plate, observing dates and times, the hour angles for the observations, length of exposure, and seeing rating. The following basic quantities were taken directly from the Catalogue of Plates: POSS number, exposure dates and times, hour angles, seeing ratings, and coordinates in sexagesimal units. The following derived quantities were calculated at the ADC: MLP number, equatorial coordinates in radians, right ascension limits, galactic coordinates, and number of SAO stars. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file nposs.dat 150 1037 List of plates of the POSS-I survey -------------------------------------------------------------------------------- See also: VI/30 : Plate Centers of the ESO Sky Survey (Holmberg+ 1974) VI/114 : Plate Centers of POSS-II (Read, 2004) Byte-by-byte Description of file: nposs.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1-4 A4 --- POSS *Palomar Observatory Sky Survey (POSS) number 6-9 I4 --- MLP *[1/1037] Modified Luyten Palomar (MLP) number 10-20 F11.8 rad RArad Equatorial coordinates (1950) of plate center 21-31 F11.8 rad DErad Equatorial coordinates (1950) of plate center 33-43 F11.8 rad RAradmin *? Minimum right ascension, R.A.(min) (1950) 44-54 F11.8 rad RAradmax ? Maximum right ascension, R.A.(max) (1950) 56-61 F6.2 deg GLON Galactic longitude (lII) of plate center 62-67 F6.2 deg GLAT Galactic latitude (bII) of plate center 69-71 I3 --- SAO *Number of SAO stars on the plate 73-76 I4 yr Obs.Y *Year of the observing night 78-80 A3 "month" Obs.M Initial Month of observing night 82-83 I2 d Obs.D Day on which the observing night began 85-87 A3 "month" fObs.M Final Month (JAN - DEC) of observing night 89-90 I2 d fObs.D Day on which the observing night ended 92-93 I2 h ObsE.h *? Start time of the red plate, hours 95-96 I2 min ObsE.m ? Start time of the red plate, minutes 98-99 I2 h ObsO.h *? Start time. of the blue plate, hours 101-102 I2 min ObsO.m ? Start time of the blue plate, minutes 104-105 I2 h EHA.h *Starting hour angle of the red plate, hours 107-108 I2 min EHA.m Starting hour angle of the red plate, minutes 110 A1 --- EHAew [EW]Direction of the hour angle, East or West 112-113 I2 h OHA.h ? Starting hour angle of blue plate, hours 115-116 I2 min OHA.m ? Starting hour angle of blue plate, minutes 118 A1 --- OHAew [EW]Direction of the hour angle, East or West 120-121 I2 min Eexp Length of exposure for the red (E) plate 123-124 I2 min Oexp *? Length of exposure for the blue (O) plate 126-128 A3 --- Erate *? Seeing rating of the red (E) plate 130-132 A3 --- Orate *? Seeing rating of the blue (O) plate 134-135 I2 h RAh Hours of right ascension, 1950 plate center 137-138 I2 min RAm Minutes of right ascension 140-141 I2 s RAs Seconds of right ascension 142 A1 --- DE- Sign of declination, 1950 plate center 143-144 I2 deg DEd Degrees of declination 146-147 I2 arcmin DEm Minutes of declination 149-150 I2 arcsec DEs Seconds of declination -------------------------------------------------------------------------------- Note on POSS: Palomar Observatory Sky Survey (POSS) number. This is the plate number of the red (E) plate as listed in the Catalogue of Plates. This machine-readable version is ordered by declination zones decreasing by roughly 6-degree decrements from +90 to -42 degrees. Within declination zones, the catalogue is ordered by increasing right ascension. The right ascension given for the two polar plates, POSS 570 and 567, describes the orientation of the plates on the sky. When the plates are oriented so that the plate label is in the top left corner, the right ascension describes the line from the plate center to the middle of the bottom edge. The POSS numbers for the plates covering the declination zone of -30 degrees contain an `S' in byte 1; the `S' must be included because some of the same plate numbers are used elsewhere in the catalogue. Records 938 to 1037 of the catalogue contain the plate information for the "Whiteoak extension." Only red-sensitive plates were taken in the extension, so certain data fields concerning the blue (O) plates are left blank. See also Section 4 below. Note on MLP: Modified Luyten Palomar (MLP) number. The MLP number is from 1 to 1037 when the catalogue is sorted by an integer quantity defined to increase sequentially declination zone in the manner described above; therefore, the MLP number can be used as a record number for the sorted catalogue. Note on RAradmin: Limits of the right ascension on the plate, in radians. The limits were computed by solving the corner equation for each plate (Nagy 1980, ADC Bull. 1, 28; Lund and Dixon 1973PASP...85..230L). The right ascension of the plate center, R.A.(center), the minimum right ascension, R.A.(min) and the maximum right ascension, R.A.(max), are such that R.A(min)) stars on the plate. This number is taken from the output multifile tape of the Palomar Plate Assignment (PPA) program described by Nagy (1980). Note on Obs.Y: The observing date for the exposure, expressed as the two dates spanned by the observing night; for example, January 31 - February 1 for overnight starting January 31. The actual calendar date of the start of an exposure must be inferred from whether the start time (bytes 101-111) is just before or just after midnight. In all cases, the red and blue plates were taken in succession to allow a comparison as free as possible from variations. Note on ObsE.h, ObsO.h: Exposure start times in Pacific Standard Time for both the red (E) and blue (O) plates. For the Whiteoak extension (MLP numbers 938 through 1037) bytes 92-102 are left blank. Note on EHA.h, OHA.h: Hour angles at the start of exposure for both the red (E) and blue (O) plates. Each exposure in the Whiteoak extension (MLP numbers 938 through 1037) was started on the meridian to maximize the quality of the plate at such low declinations (see Lund and Dixon 1973 for further details concerning the exposure techniques). Hence, the last 100 records of the catalogue list give the starting hour angle of the red plate as zero. The fields for the blue plate are blank in these fields, as only red plates were taken in the Whiteoak extension. Note on Oexp: For the Whiteoak extension, MLP numbers 938 through 1037, this field is blank. Note on Erate: Seeing rating of the red (E) plate on a scale of one to five. For the Whiteoak extension, MLP numbers 938 through 1037, this field is blank. Note on Orate: Seeing rating of the blue (O) plate on a scale of one to five. For the Whiteoak extension, MLP numbers 938 through 1037, this field is blank. -------------------------------------------------------------------------------- References: Lund J., and Dixon R. 1973PASP...85..230L Nagy T.A., 1980, ADC Bull., 1, 28 ================================================================================ (End) Julie Anne Watko [SSDOO/ADC] 12-Dec-1995