2118 II/118 UBVRI Photometric Standard Stars, Celestial Equator A U Landolt AJ 88 439 1983 1983AJ.....88..439L Photometry, UBVRI Stars, standard Stars, equatorial The catalog contains UBVRI photoelectric observations of 223 stars, mostly in an approximately 2-degree zone centered on the celestial equator. The catalog is intended to provide a uniform set of new standards, available to various sizes of telescopes in both hemispheres, on an internally consistent, homogeneous system. Most of the stars are in Selected Areas 92-115 and fall in the magnitude range of about 7 to 12.5 in V and color range -0.3 to +2.0 in B-V. The data include equatorial coordinates, photoelectric magnitudes and colors, numbers of observations, and computed internal errors.

cat Catalog abbreviation --- ID Number in catalog --- supp BD supplement letter (Barnard star) --- RAh Right ascension hours (1985.0) Positions are for equinox 1985 at epoch. However, proper motions have been accounted for in computing the 1985 coordinates for the large proper-motion stars, so these positions are given for equinox and epoch 1985.0. h RAm Right ascension minutes (1985.0) Positions are for equinox 1985 at epoch. However, proper motions have been accounted for in computing the 1985 coordinates for the large proper-motion stars, so these positions are given for equinox and epoch 1985.0. min RAs Right ascension seconds (1985.0) Positions are for equinox 1985 at epoch. However, proper motions have been accounted for in computing the 1985 coordinates for the large proper-motion stars, so these positions are given for equinox and epoch 1985.0. s DE- Sign of declination --- DEd Declination degrees (1985.0) deg DEm Declination degrees (1985.0) arcmin DEs Declination degrees (1985.0) arcsec V V magnitude Weighted V magnitude on the UBVRI photometric system, as defined by stars in Landolt (1973) and Cousins (1976). The colors are similar weighted means. mag B-V B-V color mag U-B U-B color mag V-R V-R color mag R-I R-I color mag V-I V-I color mag o_V Number of observations in weighted means --- no_V Number of nights on which star was observed --- e_V Mean error of V The mean error of a single observation of V or a color can be found by multiplying the appropriate error of the mean by the square root of n. mag e_B-V Mean error of B-V mag e_U-B Mean error of U-B mag e_V-R Mean error of V-R mag e_R-I Mean error of R-I mag e_V-I Mean error of V-I mag n_V Note flag(s) Number(s) referring to notes given at the top of the remarks file. These notes are distinct from the additional information given in Appendix I, which follows the "Notes" section in notes.txt. --- doc.txtASCII version of ADC doc. (more detailed) doc.texLaTeX version of ADC document notes.txtRemarks N. G. Roman SSDOO/ADC 1997May27Warren expressed appreciation to A. U. Landolt for providing the catalog on magnetic tape and for reviewing and commenting on a preliminary version of this document prior to its finalization for distribution with the machine-readable catalog. This document has been derived from doc.txt. UNKNOWN UNKNOWN The machine-readable data table UBVRI Photometric Standards Around the Celestial Equator was received on magnetic tape from Dr. Arlo U. Landolt on 15 April 1986. Various modifications were made by Wayne. H. Warren at the ADC in order to effect a uniformly formatted data file, to isolate the table notes from the data, and to add the additional information contained in Appendix I of the published paper. II_118.xml