This is a list of fast rotators—"

minor planet According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''minor ...

s" (which includes

asteroids An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...

) that have an exceptionally short

rotation period The rotation period of a celestial object (e.g., star, gas giant, planet, moon, asteroid) may refer to its sidereal rotation period, i.e. the time that the object takes to complete a single revolution around its axis of rotation relative to the ...

, also called "rotation rate" or "spin rate". In some cases the rotation period is not constant because the object tumbles (see List of tumblers). In this list the periods are sourced from the ''Light Curve Data Base'' (LCDB), and are given in both seconds and hours. Most minor planets have rotation periods between 2 and 20 hours. , a group of 887 bodies – most of them are stony near-Earth asteroids with small diameters of barely 1 kilometre – have an estimated period of less than 2.2 hours. According to the

Minor Planet Center The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory. Function ...

, most small bodies are thought to be

rubble pile In astronomy, a rubble pile is a celestial body that is not a monolith, consisting instead of numerous pieces of rock that have coalesced under the influence of gravity. Rubble piles have low density because there are large cavities between the ...

s – conglomerations of smaller pieces, loosely coalesced under the influence of gravity. Bodies with a period below 2.2 hours – known as the "cohesionless spin-barrier" – cannot be merely held together by self-gravity, but must be formed of a contiguous solid, as they would fly apart otherwise. Via the deduction of strength boundary limits, rotation periods give an insight into the body's internal composition, and, from its degree of fracture, its collisional history can be inferred. Bodies with an uncertain period are displayed in dark-grey. They have an

Asteroid Lightcurve Database (LCDB) In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular frequ ...

quality code, ''U'', of less than 2, which corresponds to an estimated error margin of larger than 30%. A trailing plus sign (+) or minus sign (−) indicate slightly better or worse quality, respectively, than the unsigned value. This list also includes a small group of bodies which have no

provisional designation Provisional designation in astronomy is the naming convention applied to astronomical objects immediately following their discovery. The provisional designation is usually superseded by a permanent designation once a reliable orbit has been calcu ...

in the LCDB.

Fastest rotators

Periods 0.02–0.05 hour

Periods 0.05–0.1 hour

Periods 0.1–0.5 hour

Periods 0.5–1 hour

Periods 1–2 hours

Periods 2–2.2 hours

References

External links

Asteroid Lightcurve Database (LCDB)
query form

''Geneva Observatory'',

Raoul Behrend This is a list of minor-planet discoverers credited by the Minor Planet Center with the discovery of one or several minor planets (such as near-Earth and main-belt asteroids, Jupiter trojans and distant objects). , the discovery of 612,011 numb ...

Asteroid Lightcurve Photometry Database
''

Brian D. Warner This is a list of minor-planet discoverers credited by the Minor Planet Center with the discovery of one or several minor planets (such as near-Earth and main-belt asteroids, Jupiter trojans and distant objects). , the discovery of 612,011 numb ...

''
JPL Small-Body Database Browser
''Jet Propulsion Laboratory''
Record spin for newfound asteroid
''BBC News'', May 2008

published by Ondrejov Asteroid Photometry Project {{DEFAULTSORT:Fast rotators * Lists of minor planets rotators, fast