Data Set Overview : IAU-adopted magnitude parameters (absolute V magnitude and slope parameter) for all numbered asteroids.  The absolute magnitude is variously given to 0.01, 0.1, or 1.0 mag precision, depending on the accuracy and consistency of the data used to arrive at the value.  Those slope parameters that were determined by fitting the adopted phase function [BOWELLETAL1989] to data are given an origin code letter of 'f' (for 'fitted'); all others are given a code letter of 'a' (for 'assumed'). The default value is 0.15 in all cases. Note that because most absolute magnitudes are based on apparent magnitudes measured at non-zero phase angles, the value of the absolute magnitude does depend on the assumed value for the slope parameter. A change in the assumed value of the slope parameter (based on a taxonomic classification, for example) should not be made independently of the absolute magnitude.  This version of the file contains magnitude parameters for all asteroids numbered as of the 2003 March 18 batch of Minor Planet Circulars and includes 58092 entries. The absolute magnitude database underwent a major revision recently, with updated values being published on Minor Planet Circulars 28104 through 28116. Known errors were corrected at that time, and magnitude parameters that had been taken from the literature for previous versions of the PDS database became formally adopted. Although the updated list as published in the Minor Planet Circulars includes values for all asteroids numbered as of that time, many were not changed from the previously published list. For purposes of this database, unchanged magnitude parameters retain their original reference, which should make it easier for the user to determine which have been updated.  Bowell, E., B. Hapke, D. Domingue, K. Lumme, J. Peltoniemi, and A. W. Harris 1989. Application of photometric models to asteroids. In Asteroids II (R. P. Binzel, T. Gehrels, and M. S. Matthews, Eds.), pp. 524-556. Univ. of Arizona Press, Tucson. [BOWELLETAL1989]  Spencer, J. R., L. A. Akimov, C. Angeli, P. Angelini, M. A. Barucci, P. Birch, C. Blanco, M. W. Buie, A. Caruso, V. G. Chiornij, F. Colas, P. Dentchev, N. I. Dorokhov, M. C. De Sanctis, E. Dotto, O. B. Ezhkova, M. Fulchignoni, S. Green, A. W. Harris, E. S. Howell, T. Hudecek, A. V. Kalashnikov, V. V. Kobelev, Z. B. Korobova, N. I. Koshkin, V. P. Kozhevnikov, Y. N. Krugly, D. Lazzaro, J. Lecacheux, J. MacConnell, S. Yu. Mel'nikov, T. Michalowski, B. E. A. Mueller, T. Nakamura, C. Neese, M. C. Nolan, K. S. Noll, W. Osborn, P. Pravec, D. Riccioli, V. S. Shevchenko, V. G. Shevchenko, D. J. Tholen, F. P. Velichko, C. Venditti, R. Venditti, W. Wisniewski, J. Young, and B. Zellner 1995. The lightcurve of 4179 Toutatis: Evidence for complex rotation. Icarus 117, 71-89. (K. S. Noll was added as a coauthor in an erratum published in a subsequent issue of Icarus.) [SPENCERETAL1995]  Modification History : The astermag data set was first introduced into PDS at the April 1993 asteroid data sets review. It has subsequently been updated at the March 1995, March 1996, April 1999, June 2000, May 2002, and May 2003 asteroid data sets reviews. The updates consist of adding additional data which have become available since the previous update.  Parameters : The data file contains one entry for each numbered asteroid, and each entry includes fields for the following parameters. Asteroid catalog number, absolute V magnitude, slope parameter, a code for the origin of the slope parameter, and the reference for the data.  Data : The data are presented in a single ASCII data table, 'astermag.tab'.

Review : This data set underwent external peer review on May 29, 2003.  Data Coverage and Quality : This version of the dataset contains magnitude parameters for all asteroids numbered as of the 2003 March 18 batch of Minor Planet Circulars and includes 58092 entries.