ASTEROID LIGHTCURVE DATA FILES Revised 1 March, 2001 These data files are maintained by Alan Harris, JPL. For further information or updated versions, contact: Alan Harris tel. (1)818-354-6741 MS 183-501 fax (1)818-354-0966 Jet Propulsion Laboratory e-mail awharris@lithos.jpl.nasa.gov Pasadena, CA 91109 USA The complete set of files are as follow: README.TXT This file of introductory information. LCDATPUB.TXT The lightcurve data file, with data from individual references. LCSUMPUB.TXT Summary data, one line per asteroid, no references. LCREF.TXT Reference list to all published lightcurve data. EXPLANATION In the file LCDATPUB.TXT, the first line for each asteroid is a summary of all observations which follow. It begins with the asteroid NUMBER and NAME, followedby an ORBIT CLASSIFICATION, as follows: A Apollo/Amor/Aten C Centaurs (outer planet crossing orbits) M Mars Crossers T Trojan K Kuiper Belt Objects (blank) Main belt, or none of the above The next four fields are TAXONOMIC CLASSIFICATION, DIAMETER in kilometers, ABSOLUTE MAGNITUDE, H, and ALBEDO. Diameters are mostly IRAS derived. In cases where new H values have been inserted since the IMPS, the H value is preceeded by an asterisk, and new diameter and albedos have been calculated using the method of Harris and Harris (1997). Assumed albedos are preceded by an asterisk. In these cases, diameters are calculated from the H value and asumed albedo. In the absence of other taxonomic information, a "class" is assumed, followed by an asterisk, based on orbit class or orbital semi-major axis. A and M orbit classes or main belt asteroids with a <2.7 AU are assumed "S*" class with albedo 0.18; Orbit classes C, T, K, or main belt asteroids with a > 2.8 AU are assumed "C*" or "D*", with albedo 0.058. Main-belt asteroids with a in the range 2.7-2.8 are classed "SC*" and an albedo of 0.10 is assumed. The relationship between H, diameter, and albedo is: D = (1329km)*10.**(-.2*H)/sqrt(albedo). THESE DATA ARE PROVIDED FOR CONVENIENCE ONLY, AND SHOULD NOT BE USED FOR STATISTICAL STUDIES, NOR ASSUMED TO BE ACCURATE AND CURRENT. The next entry is the ROTATION PERIOD, in hours. The value quoted is the most reliable of the individual values reported, or a subjective "best estimate" based on sometimes discordant results. By "best", we mean the value which we feel is the one most suitable for statistical analyses. In cases where the period is ambiguous, we may choose a value intermediate between possible values, weighted in favor of the more probable value. Following the period is the total RANGE OF AMPLITUDE observed at all aspects. Some adjustments have been made to estimate the amplitude which would have been observed at low phase angle at the same aspect. Next is a QUALITY CODE which summarizes the likely accuracy of the period given: 0 Result later proven incorrect. This appears only on records of individual observations (see below). 1 Result based on fragmentary lightcurve(s), may be completely wrong. 2 Result based on less than full coverage, so that the period may be wrong by 30 percent or so. Also, a quality of 2 is used to note results where an ambiguity exists as to the number of extrema per cycle or the number of elapsed cycles between lightcurves. Hence the result may be wrong by an integer ratio. 3 Denotes a secure result with no ambiguity and full lightcurve coverage. 4 In addition to full coverage, denotes that a pole position is reported. The last column is a "comment" field, see below. Following the initial line, one or more lines appear, summarizing the individual observations. One line appears for each reference which contains information on the given object. The first entry in each line is the REFERENCE, which is given more fully in the reference list. The remainder of the line contains comments, such as the OPPOSITION DATE (month/year) observed, or the provisional designation of the asteroid under which the observations are listed in the reference. The remaining space contains the period and amplitude as reported in the reference, and reliability code assigned to the observations, in the same columns as the header. If an H value is given or derivable from the observations, it too may be given in the same column as it appears in the header record. This may be the source of a revised value in the header record, noted with a preceeding asterisk. The file is not fully updated in that opposition dates and derived H values are not given for many of the earlier references. The last field of either line is reserved for notes, as follow: A Ambiguous period, alternate values of the period are listed in a short table following the main data list. B Suspected binary object based on two periods (orbit and rotation?) numbers following B are the second period and amplitude measured. N No lightcurve published. P Photographic photometry. T Tumbling - non-principal axis rotation state. V Visual photometry. 3 Number of maxima per rotation, if not 2 (e.g., 1, 3). * Preliminary, not yet published. In the case of entries referring to unpublished results, the name given is the observer who supplied the unpublished results. Any numerical information provided has been blanked in this "public" version of the data file. Contact the named observer for further information regarding any observed object. An asterisk (*) in column 5, between the asteroid number and name, or in front of the reference name on following lines, denotes a new or changed entry from the previous edition of the lightcurve list. The file LCSUMPUB.TXT consists of only the header record for each asteroid. The file LCREF.TXT contains the complete literature citation for each reference in the data file. The left column gives the "shorthand" form as it appears in the table. On the right is the proper full citation, listing all authors, year, journal, volume and page numbers.