
This is a list of slow rotators—
minor planets that have an
exceptionally long
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 ...
. This period, typically given in hours, and sometimes called rotation rate or spin rate, is a fundamental standard
physical property
A physical property is any property that is measurable, whose value describes a state of a physical system. The changes in the physical properties of a system can be used to describe its changes between momentary states. Physical properties are ...
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
slowest rotators, there are currently 15 bodies with a period longer than 1000 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
...
, 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.
Potentially slow rotators have only an inaccurate period, estimated based on a fragmentary lightcurve and inconclusive measurement. They are listed separately from the more precise periods, which have a
LCDB quality code, ''U'', of 2 or 3 (unambiguous result). The periods for potentially slow rotators may be completely wrong (''U'' = 1), have no complete and conclusive result (''U'' = n.a.), or large error margins of more than 30% (''U'' = 2−). A trailing plus sign (+) or minus sign (–) indicate slightly better or worse quality, respectively, than the unsigned value.
As with
orbital periods, a rotational period can be
sidereal or
synodic to describe a full rotation with respect to the
fixed stars
In astronomy, fixed stars ( la, stellae fixae) is a term to name the full set of glowing points, astronomical objects actually and mainly stars, that appear not to move relative to one another against the darkness of the night sky in the backgro ...
(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.
This is the case for all
main-belt asteroids, which account for 97.5% of all minor planets.
Slowest rotators
This list contains the slowest-rotating minor planets with
periods of at least 1000 hours, or 41 days. See ' for minor planets with an insufficiently accurate period—that is, a
LCDB quality code of less than 2.
Periods between 500 and 1000 hours
Periods of 400+ hours
Periods of 300+ hours
Periods of 200+ hours
Periods of 100+ hours
Potentially slow rotators
Potentially slow rotators have their
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 ...
estimated based on a fragmentary light curve. They are listed separately from the
more reliable results above, that have a
quality code (U) of 2 or higher. The periods for potentially slow rotators may be completely wrong (U=1), have no complete and conclusive result (U=n.a.), a large error margins of more than 30% (U=2−), or anything in between.
Possible periods above 1000 hours
Possible periods between 500 and 1000 hours
Possible periods of 400+ hours
Possible periods of 300+ hours
Possible periods of 200+ hours
Possible periods of 100+ hours
See also
*
Light curve
*
List of exceptional asteroids
The following is a collection of lists of asteroids of the Solar System that are exceptional in some way, such as their size or orbit. For the purposes of this article, "asteroid" refers to minor planets out to the orbit of Neptune, and includes ...
*
List of minor planets
The following is a list of numbered minor planets in ascending numerical order. With the exception of comets, minor planets are all small bodies in the Solar System, including asteroids, distant objects and dwarf planets. The catalog consists ...
References
External links
Asteroid Lightcurve Database (LCDB) query form
– Observatoire de Genève, Raoul Behrend
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
{{DEFAULTSORT:List of slow rotators
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Slow rotators (minor planets)
rotators, slow