DATA_SET_DESCRIPTION |
Data Set Overview
=================
Magnitude parameters (absolute V magnitude and slope parameter) for
all numbered asteroids. This version of the data set contains all
IAU-adopted magnitude parameters, with no exceptions. If users are
aware of improved absolute magnitude values over those in this
file, please let us know.
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 2005 April 7 batch of Minor
Planet Circulars. 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,
May 2003, May 2004, and June 2005 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'.
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