| Discovery[1] | |
|---|---|
| Discovered by | F. Gonnessiat |
| Discovery site | Algiers Obs. |
| Discovery date | 19 March 1920 |
| Designations | |
| (931) Whittemora | |
Named after | Thomas Whittemore (American archaeologist)[2] |
| A920 FB · 1920 GU A904 HB · 1904 HB | |
| Orbital characteristics[3] | |
| Epoch 31 May 2020 (JD 2459000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 115.71yr (42,264 d) |
| Aphelion | 3.9061AU |
| Perihelion | 2.4319 AU |
| 3.1690 AU | |
| Eccentricity | 0.2326 |
| 5.64 yr (2,061 d) | |
| 340.57° | |
| 0° 10m 28.92s / day | |
| Inclination | 11.484° |
| 111.00° | |
| 315.45° | |
| Physical characteristics | |
| 54±2 km[6] | |
| 19.199±0.005 h[7][8] | |
| 9.3[1][3] | |
931 Whittemora (prov. designation:A920 FBor1920 GU) is a metallicbackground asteroid, approximately 46 kilometers (29 miles) in diameter, located in the outer region of theasteroid belt. It was discovered by French astronomerFrançois Gonnessiat at theAlgiers Observatory in North Africa on 19 March 1920.[1] TheM-type asteroid has arotation period of 19.2 hours. It was named after American archaeologistThomas Whittemore (1871–1950).[2]
Whittemora is a non-family asteroid of the main belt'sbackground population when applying thehierarchical clustering method to itsproper orbital elements.[4][5] It orbits the Sun in theouter asteroid belt at a distance of 2.4–3.9 AU once every 5 years and 8 months (2,061 days;semi-major axis of 3.17 AU). Its orbit has aneccentricity of 0.23 and aninclination of 11° with respect to theecliptic.[3]
Whittemora was discovered by French astronomerFrançois Gonnessiat at theAlgiers Observatory in North Africa on 19 March 1920.[1] Two nights later, it was independently discovered byKarl Reinmuth at theHeidelberg-Königstuhl State Observatory on 21 March 1920.[2] However, theMinor Planet Center only credits Gonnessiat with the discovery.[1] The asteroid was first observed asA904 HB (1904 HB) at Heidelberg on 22 April 1904, where the body'sobservation arc begins on 21 March 1920.[1]
Thisminor planet was named after American scholar and archaeologistThomas Whittemore (1871–1950), who was professor at bothHarvard andColumbia universities. Thenaming was mentioned inThe Names of the Minor Planets byPaul Herget in 1955 (H 90).[2]
In theTholen classification,Whittemora is a metallicM-type asteroid.[3] It is an M0 in the taxonomic classification according to the method used by Barucci (1987).[5]
In March 2016, a rotationallightcurve ofWhittemora was obtained fromphotometric observations by French and Swiss astronomersChristophe Demeautis, Mickael Porte andRaoul Behrend. Lightcurve analysis gave arotation period of19.199±0.005 hours with a brightness variation of0.25±0.02magnitude (U=2+).[7][8] This result supersedes a period determination of 16+ hours byPierre Antonini from June 2006 (U=2), and of19.20±0.01 hours with an amplitude of0.2±0.05 magnitude by John Menke at the Menke Observatory in January 2004 (U=2).[12]
According to the survey carried out by the Infrared Astronomical SatelliteIRAS, theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer (WISE), and the JapaneseAkari satellite,Whittemora measures (45.27±3.4), (45.298±0.727) and (48.98±1.01) kilometers in diameter and its surface has analbedo of (0.1704±0.028), (0.170±0.050) and (0.148±0.007), respectively.[11][10][9]
TheCollaborative Asteroid Lightcurve Link adopts the results from IRAS, that is, an albedo of 0.1704 and a diameter of 45.27 km based on anabsolute magnitude of 9.26.[8] Further published mean-diameters and albedos by the WISE team include (40.619±2.021 km) and (56.841±0.673 km) with corresponding albedos of (0.212±0.051), and (0.1085±0.0270).[5][8] Twoasteroid occultations on 1 January 2004 and 12 February 2015, gave a best-fit ellipse dimension of 45.0 × 45.0 and 49.0 × 49.0 kilometers, respectively.[5] These timed observations are taken when the asteroid passes in front of a distant star. However the quality of the measurements are poorly rated.[5]
