List of slow rotators (minor planets)

In recent years, the periods of many thousands of bodies have been obtained from photometric and, to a lesser extent, radiometric observations.

[1][3] As of 2019[update], a group of approximately 650 bodies, typically measuring 1–20 kilometers in diameter, have periods of more than 100 hours or 41⁄6 days.

[1] 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.

[3] Potentially slow rotators have only an inaccurate period, estimated based on a fragmentary lightcurve and inconclusive measurement.

See § Potentially slow rotators for minor planets with an insufficiently accurate period—that is, a LCDB quality code of less than 2.

This plot shows the distribution of rotation periods for 15,000 minor planets, plotted against their diameters. Most bodies have a period between 2 and 20 hours. [ 1 ] [ a ]