1810 Epimetheus

1810 Epimetheus Template:IPAc-en, provisional designation Template:Mp, is a stony Florian asteroid from the inner regions of the asteroid belt, approximately 8 kilometers in diameter.

It was discovered on 24 September 1960, by Dutch astronomer couple Ingrid and Cornelis van Houten, and Dutch–American astronomer Tom Gehrels during the Palomar–Leiden survey at Palomar Observatory in California, United States.<ref name="MPC-Epimetheus" /> It was later named after Epimetheus from Greek mythology.<ref name="springer" />

Classification and orbit

The S-type asteroid is a member of the Flora family, one of the largest groups of stony asteroids in the main-belt. It orbits the Sun at a distance of 2.0–2.4 AU once every 3 years and 4 months (1,211 days). Its orbit has an eccentricity of 0.09 and an inclination of 4° with respect to the ecliptic.<ref name="jpldata" />

The body's observation arc begins with its official discovery observation, as the previous identifications, Template:Mp and Template:Mp, made at Johannesburg and Uccle in 1942 and 1950, respectively, remained unused.<ref name="MPC-Epimetheus" />

Physical characteristics

Rotation period

Two divergent rotational lightcurves of Epimetheus were obtained from photometric observations. They gave a rotation period of 10.9 and 28.6 hours with both having a brightness variation of 0.04 magnitude (Template:Small).<ref name="Brinsfield-2008c" />Template:Efn

Diameter and albedo

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Epimetheus measures 7.7 kilometers in diameter and its surface has an albedo of 0.27,<ref name="Masiero-2012" /> while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from 8 Flora, the largest member and namesake of its orbital family – and calculates a diameter of 8.2 kilometers, based on an absolute magnitude of 12.6.<ref name="lcdb" />

Survey designation

The survey designation "P-L" stands for Palomar–Leiden, named after Palomar Observatory and Leiden Observatory, which collaborated on the fruitful Palomar–Leiden survey in the 1960s. Gehrels used Palomar's Samuel Oschin telescope (also known as the 48-inch Schmidt Telescope), and shipped the photographic plates to Ingrid and Cornelis van Houten at Leiden Observatory where astrometry was carried out. The trio are credited with the discovery of several thousand minor planets.<ref name="MPC-discoverers" />

Naming

This minor planet is named for the Titan in Greek mythology, Epimetheus, who opened Pandora's box, which contained all the illnesses and ailments of mankind (also see 55 Pandora). Epimetheus is also a moon of Saturn, which was discovered by Voyager 1 in 1980. Epimetheus is the brother of Prometheus after whom the minor planet 1809 Prometheus was named.<ref name="springer" /> The official Template:MoMP was published by the Minor Planet Center on 20 February 1976 (Template:Small).<ref name="DoMP-Circular-dates" />

External links

• Asteroid Lightcurve Database (LCDB), query form (info Template:Webarchive)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
• Template:AstDys
• Template:JPL small body