Data Set Information
DATA_SET_NAME ASTEROID SPIN VECTOR COMPILATION V5.0
DATA_SET_ID EAR-A-5-DDR-ASTEROID-SPIN-VECTORS-V5.0
NSSDC_DATA_SET_ID
DATA_SET_TERSE_DESCRIPTION
DATA_SET_DESCRIPTION Data Set Overview : This is a comprehensive tabulation of asteroid spin vector determinations, compiled by Agnieszka Kryszczynska and based on the earlier compilation by Per Magnusson. This is the Oct. 21, 2007 version of the compilation, containing 863 spin vector determinations. Supplementary information on shape models and albedo variegation is also included, but only when part of a spin vector determination. The following files are included in the data set: data/spin.tab - A machine-readable ASCII version of the spin vectors compilation data/spinrefs.tab - A list of the references cited in spin.tab data/spinnotes.tab - A list of the notes to the spin.tab table documents/spin.pdf - An Adobe pdf version of the spin vectors compilation, designed to be easily readable by eye. It contains the same information as spin.tab documents/spininfo.asc - An explanatory document about the spin vectors compilation For some asteroids a large number of independent solutions have been published. This may be confusing for readers who are not interested in the spin vector determination process as such. For the benefit of readers who just want reliable results for their own applications a 'synthesis' is included for each asteroid. These synthesis results are estimated by Kryszczynska to have a high reliability and an accuracy in the spin vector direction of order 10 degrees or less. They were obtained by taking averages of the most recent independent results, with weights based on the method used and the amount and type of the input data. This procedure is necessarily somewhat subjective, and can't replace a careful evaluation of the original results. The direction of the spin vectors (defined by the 'right-hand-rule') are given in degrees in the ecliptic system for equinox B1950.0. The corresponding ecliptic coordinates for equinox J2000.0 can be obtained by adding 0.7 degrees to all tabulated longitudes, but this adjustment is far below the level of accuracy for most spin vector determinations. The table contains column space for four spin vector directions per line. These reflect the symmetry properties of most spin vector determinations. Methods based on aspect dependences (e.g. amplitude and magnitude methods) tend to give two spin axis solutions for main-belt asteroid with moderate orbital inclination (due to the near symmetry of the observational geometries in the ecliptic plane). Corresponding to each spin axis solution are two opposite spin vector directions, which are given explicitly in the table. Thus, whenever the method used does not contain information on the sense of rotation, 'poles' are interpreted as spin axis solutions and the implicit spin vector directions are calculated. The result is generally four different solutions. Generally the two prograde solutions are placed in the two left columns and the two retrograde ones in the columns to the right. If subsequent determinations agree reasonably then corresponding solutions appear in the same column, making comparison easy. The 4-fold symmetry is not applicable to certain objects. The distinction between the four groups may break down for objects in high inclination orbits (e.g. 2 Pallas), for objects with spin axes close to the ecliptic plane, and for objects whose lightcurves are difficult to interpret (e.g. 532 Herculina). For Earth-approaching objects it often reduces to a 2-fold clustering. For a discussion and analysis of this data set see Kryszczynska et al. 2007. This compilation of asteroid spin vectors supersedes the earlier compilations by Per Magnusson, upon which it has been based. References : Kryszcznska, A., A. La Spina, P. Paolicchi, A.W. Harris, S. Breiter, and P. Pravec, New findings on asteroid spin-vector distributions, Icarus 192, 223-237, 2007.
DATA_SET_RELEASE_DATE 2008-06-12T00:00:00.000Z
START_TIME 1932-01-01T12:00:00.000Z
STOP_TIME 2007-10-21T12:00:00.000Z
MISSION_NAME SUPPORT ARCHIVES
MISSION_START_DATE 2004-03-22T12:00:00.000Z
MISSION_STOP_DATE N/A (ongoing)
TARGET_NAME ASTEROID
TARGET_TYPE ASTEROID
INSTRUMENT_HOST_ID PUBLIT
INSTRUMENT_NAME COMPILATION
INSTRUMENT_ID COMPIL
INSTRUMENT_TYPE UNKNOWN
NODE_NAME Small Bodies
ARCHIVE_STATUS LOCALLY_ARCHIVED
CONFIDENCE_LEVEL_NOTE Confidence Level Overview : Sidereal Periods : Only periods accurate enough to bridge inter-apparitional gaps and produce absolute rotational phases for the whole data set are included. Less accurate synodic period determinations exist for many more objects. As evident from the table, the agreement between sidereal period determinations tend to be either very good or very bad. This is due to the non-uniform time-distribution of the observations, which tend to give many well-defined local chi-square minima. Ellipsoidal Models : Many pole determination methods are based on a tri-axial ellipsoid model with semi-axes a>:b>:c rotating about the c-axis. Corrections for non- geometric scattering and albedo variegation have often not been made. A warning must therefore be made against direct identification of the model axis-ratios with the asteroid shape. Note that the table is not a comprehensive list of asteroid shapes, but includes models obtained as by-products of spin vector determinations only. Albedo Variegation : Albedo models are also often by-products of spin-vector determinations, and therefore noted in the table. However, the table is not a complete collection of such models.
CITATION_DESCRIPTION Kryszczynska, A. and Magnussen, P., Asteroid Spin Vector Compilation V5.0. EAR-A-5-DDR-ASTEROID-SPIN-VECTORS-V5.0. NASA Planetary Data System, 2008.
ABSTRACT_TEXT This is a comprehensive tabulation of asteroid spin vector determinations, compiled by Agnieszka Kryszczynska and based on the earlier compilation by Per Magnusson. This is the Oct. 21, 2007 version of the compilation, containing 863 spin vector determinations.
PRODUCER_FULL_NAME CAROL NEESE
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