List of slow rotators (minor planets)
Minor planet designation Rotation period ( hours ) Δ mag Quality ( U ) Orbit or family Spectral type Diameter ( km ) Abs . mag ( H ) Refs
( 22135 ) 2000 UA 100 393 0.25 2− Eunomia S 6.96 13.10 LCDB · List
( 98063 ) 2000 RG 48 358.3 0.08 1 Flora S 1.73 15.98 LCDB · List
( 266992 ) 2010 XR 43 350 - n.a Jupiter trojan C 12.18 13.30 LCDB · List
5511 Cloanthus 336 0.49 2− Jupiter trojan C 48.48 10.30 LCDB · List
( 381677 ) 2009 BJ 81 325 0.40 n.a NEO S 0.65 18.30 LCDB · List
( 36227 ) 1999 UR 5 322 0.07 1 MBA ( outer ) C 12.11 13.31 LCDB · List
Potentially slow rotators -- Possible periods of 300+ hours
This is a list of slow rotators - minor planets that have an exceptionally long rotation period. This period, typically given in hours, and sometimes called rotation rate or spin rate, is a fundamental standard physical property for minor planets. In recent years, the periods of many thousands of bodies have been obtained from photometric and, to a lesser extent, radiometric observations. The periods given in this list are sourced from the Light Curve Data Base (LCDB), which contains lightcurve data for more than 15,000 bodies. Most minor planets have rotation periods between 2 and 20 hours. , a group of approximately 650 bodies, typically measuring 1-20 kilometers in diameter, have periods of more than 100 hours or 4 days. Among the , there are currently 15 bodies with a period longer than 1000 hours. According to the Minor Planet Center, the sharp lower limit of approximately 2.2 hours is due to the fact that most smaller bodies are thought to be rubble piles - conglomerations of smaller pieces, loosely coalesced under the influence of gravity - that fly apart if the period is shorter than this limit. The few minor planets rotating faster than 2.2 hours, therefore, can not be merely held together by self-gravity, but must be formed of a contiguous solid. As with orbital periods, a rotational period can be sidereal or synodic to describe a full rotation with respect to the fixed stars (sidereal) and Sun (synodic), respectively. In most cases, the periods given in this list are synodic, not sidereal. However, in most cases the difference between these two different measures is not significant.