Data Set Information
DATA_SET_NAME ASTEROID SPIN VECTORS
DATA_SET_ID EAR-A-5-DDR-ASTEROID-SPIN-VECTORS-V4.2
NSSDC_DATA_SET_ID
DATA_SET_TERSE_DESCRIPTION
DATA_SET_DESCRIPTION Data Set Overview : This is a tabulation of 526 determinations of asteroid pole orientations, covering 104 numbered asteroids, gathered from the literature from 1932 through 1995. It is an updated (Dec. 1995) version of the tabulation given in Magnusson (1989) [MAGNUSSON1989] in the Asteroids II book. For more information about the Uppsala Asteroid Database, of which this collection is a part, see Magnusson et al. 1993 [MAGNUSSONETAL1993]. Modification History : This data set was first introduced into PDS under the name 'pole' at the April 1994 asteroid datasets review. It was updated under the name 'pole' at the March 1995 review. It was then updated under the new name 'spin' at the March 1996 review. An update consists of adding data on asteroid spin vectors which have been published since the last update. Note that the prefix of the above DATA_SET_ID was changed from 'A-5' to 'EAR-A-5' effective with version 4.0 of this data set. For Version 4.1, the original labels and this catalog file were substantially edited to conform with present PDS and SBN standards and practices. These changes included: o The long text passage included in the general description of the label file was extracted into a separate documentation file, 'spindoc.txt'. In addition, relevant pieces of it were used to create DESCRIPTION fields for individual columns in the 'spin.lbl' file and the present file. o The list of numbered notes was removed from the label and converted to a separate file, 'spinnote.tab', with its own label. o The list of data type codes was inserted into the first relevant column description in 'spin.lbl'. o Column NAME fields in 'spin.lbl' were changed to shorter, more displayable versions. o A typographical error in the REFERENCE_CODE column of 'spin.tab' records 459 and 460 was discovered and corrected by inserting a '+' into the code. o The old TeX listing of the original published paper, 'spindoc.tex', and all the related supporting files have been discarded. These files were not kept up to date with the revised data file. o The visually distracting and programmatically complicating underscores used to indicate null data were removed from 'spin.tab'. The 'spin.lbl' file was changed to state that blank fields indicate null data. o The text of this file was checked against the available documentation and revised labels and amended as needed. o A user reported that the labels for latitude and longitude columns appeared to be switched, i.e., longitudes were labelled and latitude and conversely. This has been corrected in the label. Parameters : The data table 'spin.tab' contains an entry for each of 526 published determinations of asteroid spins, plus an additional synthesis entry for each asteroid for which such a synthesis was warranted. Each entry has fields for the following parameters: asteroid catalog number; a code for the type of data used to make the determination; four solutions for the asteroid spin direction (including rejection flag and pole latitude and longitude); sidereal period; flag for shape model; axial ratios; reference code; and notes. Processing : The principal data are taken from the published literature. In some cases the data supplier (P. Magnusson) converted published pole positions into spin axis solutions for inclusion. The following description is from the documentation file supplied with the data (and contained in 'spindoc.txt') by P. Magnusson: 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 we have 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 I interpret 'poles' as spin axis solutions and calculate the implicit spin vector directions. The result is generally four different solutions. In addition, for asteroids with a large number of published pole solutions, Magnusson has created additional entries containing a synthesis of published results. Data : The following files (and their labels) constitute the data set: spin.tab Tabulation of published results spinref.tab List of reference codes and citations spinnote.tab List of numbered notes spindoc.txt Documentation file Ancillary Data : The data set also includes a table of full references to the original papers in which the data were published. The references file is 'spinref.tab'. Each entry in the data table includes a pointer to the reference file giving the reference of the original paper for that entry. The 'spinnote.tab' file contains the numbered list of notes mentioned in the 'spin.tab' file. Coordinate System : The pole positions are expressed as ecliptic latitude and longitude, equinox B1950.0. Magnusson notes: 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.
DATA_SET_RELEASE_DATE 1996-03-29T00:00:00.000Z
START_TIME 1932-01-01T12:00:00.000Z
STOP_TIME 1995-12-31T12:00:00.000Z
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 SUPERSEDED
CONFIDENCE_LEVEL_NOTE Confidence Level Overview : This is a comprehensive tabulation of determinations of asteroid pole orientations and senses of rotation. No weeding out of vague or uncertain results has been made. Data Coverage and Quality : The data set includes data on asteroid pole directions published through 1995. 152 references are cited; 526 solutions are included in the 'spin.tab' file; 104 different asteroids are represented. Supplementary information on shape models, albedo models, and sidereal period is included, but this data set is not intended to be a comprehensive compilation of those parameters. For those records containing a synthesis of published solutions, Magnusson notes: The synthesis entry is estimated to have an accuracy in the spin vector of 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 cannot replace a careful evaluation of the original results. Limitations : This data set is intended only to collect data reported in the published literature on asteroid pole directions.
CITATION_DESCRIPTION Magnusson, P. and Neese, C., Eds., Asteroid Spin Vectors. EAR-A-5-DDR-ASTEROID-SPIN-VECTORS-V4.2. NASA Planetary Data System, 1996.
ABSTRACT_TEXT This is a tabulation of 526 determinations of asteroid pole orientations, covering 104 numbered asteroids, gathered from the literature from 1932 through 1995.
PRODUCER_FULL_NAME CAROL NEESE
SEARCH/ACCESS DATA
  • SBN PSI WEBSITE
    		•