118 Peitho is a
main-belt asteroid
An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...
. It is probably an
S-type asteroid, suggesting a
siliceous mineralogy. It was discovered by
R. Luther on March 15, 1872, and named after one of the two
Peithos in
Greek mythology
Greek mythology is the body of myths originally told by the Ancient Greece, ancient Greeks, and a genre of ancient Greek folklore, today absorbed alongside Roman mythology into the broader designation of classical mythology. These stories conc ...
. There have been two observed Peithoan
occultations of a dim
star
A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sk ...
: one was in 2000 and the other in 2003.
This body is orbiting the
Sun with a
period of 3.81 years and an
eccentricity
Eccentricity or eccentric may refer to:
* Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal"
Mathematics, science and technology Mathematics
* Off-Centre (geometry), center, in geometry
* Eccentricity (g ...
(ovalness) of 0.16. The
orbital plane is
inclined by 7.7° to the
plane of the ecliptic
The ecliptic or ecliptic plane is the orbital plane of Earth around the Sun. It was a central concept in a number of ancient sciences, providing the framework for key measurements in astronomy, astrology and calendar-making.
From the perspe ...
. The cross-section diameter is ~42 km. In 2009,
Photometric observations of this asteroid were made at the Palmer Divide Observatory in
Colorado Springs, Colorado
Colorado Springs is the most populous city in El Paso County, Colorado, United States, and its county seat. The city had a population of 478,961 at the 2020 United States census, 2020 census, a 15.02% increase since 2010 United States Census, 2 ...
. The resulting asymmetrical
light curve
In astronomy, a light curve is a graph (discrete mathematics), graph of the Radiance, light intensity of a celestial object or region as a function of time, typically with the magnitude (astronomy), magnitude of light received on the ''y''-axis ...
shows a synodic
rotation period
In astronomy, the rotation period or spin period of a celestial object (e.g., star, planet, moon, asteroid) has two definitions. The first one corresponds to the '' sidereal rotation period'' (or ''sidereal day''), i.e., the time that the objec ...
of 7.823 ± 0.002 hours with a brightness variation of 0.15 ± 0.02 in
magnitude. This was reasonably consistent with independent studies performed in 1980 (7.78 hours) and 2009 (7.8033 hours).
The
lightcurve inversion process has been used to construct a model of this object,
[ suggesting a blocky shape with flattened poles.
]
References
External links
Lightcurve plot of 118 Peitho
Palmer Divide Observatory, '' B. D. Warner'' (2009)
Asteroid Lightcurve Database (LCDB)
query form
)
Dictionary of Minor Planet Names
Google books
– Observatoire de Genève, Raoul Behrend
– Minor Planet Center
*
*
000118
Discoveries by Robert Luther
Named minor planets
000118
000118
000118
18720315
{{S-beltasteroid-stub