Data Set Overview : Sizes, shapes, colors and albedos of comet nuclei culled from the literature as presented in the following papers:  Belton et al. (2004) Boehnhardt et al. (2008) Hsieh et al. (2009) Kelley et al. (2009) Knight et al. (2010) Lamy et al. (2004, 2008,2009, 2010) Lowry and Fitzsimmons (2005) Lowry and Weissman (2007) Snodgrass et al. (2005, 2006, 2008, 2010) Stansberry et al. (2004) Tubiana et al. (2008)  Parameters : Measurements of effective radius, axial ratio and period are presented for 164 comets and 35 asteroidal objects suspected of being dormant or extinct comet nuclei. Additional tables present colors, albedos, and dimensions of nuclei.  In most cases of shapes determined from light curves (all but the 4 space mission targets), the values of one axis or another are limits. In particular, generally one measures a lower limit to the ratio a/b (and usually assumes c:b unless there are observations at many different phases), plus a product of a and b. This pretty much means a lower limit on a and an upper limit on b.  Processing : These data have been keyed in to flat ASCII tables from the published paper. The format has been modified slightly to accommodate PDS standards, usual SBN practices, and the preferences of users as expressed by the external reviewers.  Modification History : Version 2.0 of this data set includes the addition of more recent data since version 1.0 was released in 2005 and corrects typographical errors in comet names, discovery IDs, and references used in several data products.  Media/Format : These data are available online for immediate downloading.

Confidence Level Overview : The papers whose data have been included in this dataset contain extensive remarks regarding the various observations and measurements included in these tables. While the tables present an excellent summary of the state of knowledge, the user is strongly encouraged to consult the published paper for the various caveats and notations included in the remarks.