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VI/42       Identification of a Constellation From Position  (Roman 1987)

Identification of a Constellation from a Position Roman N. G. <Pub. Astron. Soc. Pac. 99, 695, (1987)> =1987PASP...99..695R
ADC_Keywords: Constellations Description: A table of constellation boundaries was rearranged to permit the rapid identification of the constellation to which a position refers. A software program is provided to precess positions at another equinox to those at 1875.0. Introduction: Barry Rappaport put the list of constellation boundaries that was published in 1930 (Delporte 1930) into electronic form. This form made it convenient to manipulate the data into an arrangement that is easier to use for finding a constellation from a position. The southern boundaries of each constellation are listed in order of declination and then by the eastern terminus of each declination arc. A program, in FORTRAN77, for determining the constellation using the data in data.dat is provided in two forms. Comments describe the format in which the positions must be entered. The main program is followed by a precession subroutine which permits the use of positions at any epoch. The file data.dat is a list of constellation boundaries in the form Lower Right Ascension, Upper Right Ascension, Lower Declination, three letter abbreviation for the Constellation. The following is an example of the output of the program: RA = 9.0000 DEC = 65.0000 IS IN CONSTELLATION UMa RA = 23.5000 DEC = -20.0000 IS IN CONSTELLATION Aqr RA = 5.1200 DEC = 9.1200 IS IN CONSTELLATION Ori RA = 9.4555 DEC = -19.9000 IS IN CONSTELLATION Hya RA = 12.8888 DEC = 22.0000 IS IN CONSTELLATION Com RA = 15.6687 DEC = -12.1234 IS IN CONSTELLATION Lib RA = 19.0000 DEC = -40.0000 IS IN CONSTELLATION CrA RA = 6.2222 DEC = -81.1234 IS IN CONSTELLATION Men END OF INPUT POSITIONS AFTER: RA = 6.2222 DEC = -81.1234 THE EQUINOX FOR THESE POSITIONS IS 1950.0 A C version of the program for those who have not access to a f77 compiler is also available. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file program.f 76 127 FORTRAN version of the software program.c 77 156 C version of the software data.dat 29 357 The data file with constellation boundaries
Byte-by-byte Description of file: data.dat
Bytes Format Units Label Explanations
2- 8 F7.4 h RA_low Lower right ascension range, equinox=1875 10- 16 F7.4 h RA_up Upper right ascension range, equinox=1875 18- 25 F8.4 deg DE_low Lower (southern) declination, equinox=1875 27- 29 A3 --- const Constellation name
History: * 30-Dec-1999: one line (#229) was corrected by Nancy G. Roman References: Delporte, E. 1930, Delimitation Scientifique des Constellations, Cambridge: Cambridge U. Press Roman N.G. 1987, Publ. Astron. Soc. Pacific, 99, 695-699
(End) Nancy Grace Roman [ADC/SSDOO] 22-Feb-1996
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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