_Ra%25C3%25AFssa.png) Shape model ofRaïssa from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | G. Neujmin |
| Discovery site | Simeiz Obs. |
| Discovery date | 27 October 1929 |
| Designations | |
| (1137) Raïssa | |
Named after | Raïssa Maseeva (Russian astronomer)[2] |
| 1929 WB · A908 BB A910 TB · A924 JA | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 113.28 yr (41,374 days) |
| Aphelion | 2.6600AU |
| Perihelion | 2.1865 AU |
| 2.4233 AU | |
| Eccentricity | 0.0977 |
| 3.77yr (1,378 days) | |
| 132.76° | |
| 0° 15m 40.68s / day | |
| Inclination | 4.3162° |
| 78.455° | |
| 277.00° | |
| Physical characteristics | |
| 19.421±0.192 km[6] 20.029±0.132 km[7] 21.21±0.55 km[8] 23.66 km(derived)[9] 23.69±1.1 km[10] | |
| 142.79±0.01 h[11] | |
| 0.1538(derived)[9] 0.1592±0.015[10] 0.206±0.013[8] 0.2207±0.0712[7] 0.228±0.027[6] | |
| 10.6[1] · 10.74[8][10] · 10.78[9][7][12] | |
1137 Raïssa (prov. designation:1929 WB) is a stonybackground asteroid andslow rotator, approximately 22 kilometers (14 miles) in diameter, located in the inner regions of theasteroid belt. It was discovered byGrigory Neujmin atSimeiz Observatory in 1929, and named in memory of Raïssa Maseeva, who worked at thePulkovo Observatory.[2]
Raïssa was discovered on 27 October 1929, by Soviet astronomerGrigory Neujmin at theSimeiz Observatory on theCrimean peninsula.[3] In the following month, it was independently discovered by GermanKarl Reinmuth at theHeidelberg Observatory on 21 November 1929.[2] TheMinor Planet Center only acknowledges the first discoverer.[3] The asteroid'sobservation arc begins at theUnited States Naval Observatory in December 1903, almost 26 years prior to its official discovery observation at Simeiz. Its first identification asA908 BB was made at Heidelberg in January 1908.[3]
Raïssa 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 theinner asteroid belt at a distance of 2.2–2.7 AU once every 3 years and 9 months (1,378 days). Its orbit has aneccentricity of 0.10 and aninclination of 4° with respect to theecliptic.[1]
Thisminor planet was named in memory of Raïssa Izrailevna Maseeva (1900–1930), a scientific collaborator who worked at thePulkovo Observatory. The official naming citation was mentioned inThe Names of the Minor Planets byPaul Herget in 1955 (H 106).[2]
Raïssa is an assumed stonyS-type asteroid.[9]
In October 2010, a rotationallightcurve ofRaïssa was obtained fromphotometric observations at the Bigmuskie Observatory (B88), Italy, and the Etscorn Campus (719) and Organ Mesa Observatory (G50) in New Mexico, United States. Lightcurve analysis gave arotation period of 142.79 hours with a brightness variation of 0.56magnitude (U=3-).[11] Previous observations with a shorter period were superseded.[13][12]
With a rotation period of close to six Earth days,Raïssa is aslow rotator as most asteroids have periods of 20 hours or less. Collaborations of observers located on different longitudes, e.g. in the U.S. and Europe are especially important for asteroids with very long periods. The observers can follow the bodies brightness variation at different starting points and thereby cover parts of the lightcurve that were missed by other observers during their daytime.[11]
In 2016, a modeled lightcurve using photometric data from various sources gave a concurring period of143.644±0.005 hours and twospin axis of (222.0°, −66°) and (40.0°, −77.0°) inecliptic coordinates.[5][14]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Raïssa measures between 19.421 and 23.69 kilometers in diameter and its surface has analbedo between 0.1592 and 0.228.[6][7][8][10] TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.1538 and a diameter of 23.66 kilometers based on anabsolute magnitude of 10.78.[9]
