PDS_VERSION_ID = PDS3 OBJECT = DATA_SET DATA_SET_ID = "EAR-A-5-DDR-ASTERMAG-V2.0" DATA_SET_LOCAL_ID = "ASTERMAG" OBJECT = DATA_SET_INFORMATION DATA_SET_NAME = "Asteroid Absolute Magnitudes V2.0" DATA_SET_COLLECTION_MEMBER_FLG = "N" DATA_OBJECT_TYPE = TABLE START_TIME = "N/A" STOP_TIME = "N/A" DATA_SET_RELEASE_DATE = 1995-03-31 /* Peer Review Date */ PRODUCER_FULL_NAME = "David J. Tholen" DETAILED_CATALOG_FLAG = "N" DATA_SET_DESC = " 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 IAU-adopted phase function (see Bowell et al. 1989) 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. 'MPC' in the reference field stands for 'Minor Planet Circular', published on behalf of Commission 20 of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138. This version of the dataset contains magnitude parameters for all asteroids numbered as of the 1995 February 15 batch of Minor Planet Circulars and includes 6259 entries. Although errors are known to exist, more accurate values have yet to be adopted by the IAU. In two cases, described in the notes, the IAU-adopted values were replaced by better ones. Improved values will be incorporated into this database after they become formally adopted. The Asteroid Subnode of the Planetary Data System would be happy to accept published values of improved magnitude parameters for forwarding to the appropriate IAU committee. Comments on individual entries in the dataset: (1) The absolute magnitude of 16 for (878) Mildred was adopted by the IAU prior to the recovery of this formerly lost asteroid (see MPC 17260). Following recovery, the inclusion of new and recent astrometric observations led to a significant revision of the absolute magnitude for this object (see MPC 18400). ASTERMAG.DAT reflects this more recent value, rather than the older IAU-adopted value. (2) The IAU-adopted absolute magnitude of 14.0 for (4179) Toutatis (see MPC 17271) was known to be seriously in error prior to this Apollo asteroid's 1992 December 08 close approach to the Earth. The values included here are from Spencer et al. (1994). References: 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. Spencer, J. R., L. A. Akimov, C. Angeli, P. Angelini, M. A. Barucci, P. Birch, C. Blanco, M. Buie, A. Caruso, V. G. Chiornij, F. Colas, P. Dentchev, M. C. De Sanctis, E. Dotto, M. Fulchignoni, S. Green, A. Harris, T. Hudecek, A. V. Kalashnikov, V. V. Kobelev, V. P. Kozhevnikov, Y. Krugly, D. Lazzaro, J. Lecacheux, J. MacConnell, T. Michalowski, R. A. Mohamed, B. Mueller, T. Nakamura, C. Neese, W. Osborn, P. Pravec, D. Riccioli, V. Shevchenko, D. Tholen, F. Velichko, C. Venditti, R. Venditti, W. Wisniewski, J. Young, and B. Zellner 1994. The lightcurve of 4179 Toutatis: Evidence for complex rotation. Icarus (submitted). 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, the reference for the data, and a note flag. Data ==== The data are presented in a single ASCII data table, 'astermag.tab'. Media/Format ============ This dataset is released in the form of ASCII files which may be stored on disk or other magnetic medium and which may be distributed by ftp, email, real-time access by remote login, or by whatever means is most convenient. " CONFIDENCE_LEVEL_NOTE = " Review ====== This dataset underwent a formal external review on March 31, 1995. Data Coverage and Quality ========================= This version of the dataset contains magnitude parameters for all asteroids numbered as of the 1995 February 15 batch of Minor Planet Circulars and includes 6259 entries. Although errors are known to exist, more accurate values have yet to be adopted by the IAU. In two cases, described in the notes, the IAU-adopted values were replaced by better ones. Improved values will be incorporated into this database after they become formally adopted. The Asteroid Subnode of the Planetary Data System would be happy to accept published values of improved magnitude parameters for forwarding to the appropriate IAU committee. " END_OBJECT = DATA_SET_INFORMATION OBJECT = DATA_SET_TARGET TARGET_NAME = "ASTEROID" END_OBJECT = DATA_SET_TARGET OBJECT = DATA_SET_HOST INSTRUMENT_HOST_ID = "N/A" INSTRUMENT_ID = "N/A" END_OBJECT = DATA_SET_HOST OBJECT = DATA_SET_REFERENCE_INFORMATION REFERENCE_KEY_ID = "MPC" END_OBJECT = DATA_SET_REFERENCE_INFORMATION END_OBJECT = DATA_SET OBJECT = REFERENCE REFERENCE_KEY_ID = "MPC" REFERENCE_DESC = "Minor Planet Circular, published on behalf of Commission 20 of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, Brian G. Marsden, Editor." END_OBJECT = REFERENCE END