| Discovery[1] | |
|---|---|
| Discovered by | H. Potter A. Lokalov |
| Discovery site | Cerro El Roble Stn. |
| Discovery date | 8 January 1970 |
| Designations | |
| (2975) Spahr | |
Named after | Timothy Spahr[1] (MPC director) |
| 1970 AF1 · 1957 HU 1967 GH · 1970 AK1 1970 CB · 1978 PF4 | |
| main-belt[1][2] · (inner) background[3][4] · Flora[5] | |
| Orbital characteristics[2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 61.07yr (22,304 d) |
| Aphelion | 2.4621AU |
| Perihelion | 2.0351 AU |
| 2.2486 AU | |
| Eccentricity | 0.0949 |
| 3.37 yr (1,232 d) | |
| 44.830° | |
| 0° 17m 32.28s / day | |
| Inclination | 6.8979° |
| 236.58° | |
| 317.02° | |
| Physical characteristics | |
| 5.919±0.107 km[6] 6.032±0.082 km[7] 6.51 km(calculated)[5] | |
| 11.946±0.006 h[8] | |
| 0.24(assumed)[5] 0.4044±0.0445[7] 0.419±0.085[6] | |
| S(SDSS-MOC)[9] S(Pan-STARRS)[5][10] A(S3OS2-TH)[11] A(S3OS2-BB)[11] | |
| 12.7[7] 13.0[1][2] 13.1[5] 13.81±0.38[10] | |
2975 Spahr, provisional designation1970 AF1, is a bright backgroundasteroid from the Flora region of the innerasteroid belt, approximately 6 kilometers (3.7 miles) in diameter. It was discovered on 8 January 1970, by Russian astronomersHejno Potter andA. Lokalov at theCerro El Roble Station near Santiago, Chile.[1] TheS- orA-type asteroid has arotation period of 11.9 hours.[5] It was named forTimothy Spahr, an American astronomer and former director of theMinor Planet Center.[12]
Spahr is a non-family asteroid of the main belt'sbackground population when applying thehierarchical clustering method to itsproper orbital elements.[3][4] Based on osculating Keplerianorbital elements, the asteroid has also been classified as a member of theFlora family (402), a giantasteroid family and the largest family of stony asteroids in the main-belt.[5]
It orbits the Sun in theinner asteroid belt at a distance of 2.0–2.5 AU once every 3 years and 4 months (1,232 days;semi-major axis of 2.25 AU). Its orbit has aneccentricity of 0.09 and aninclination of 7° with respect to theecliptic.[2]
The asteroid was first observed as1957 HU at the Johannesburg-Hartbeespoort Observatory (076) in April 1957. The body'sobservation arc begins as1967 GH atCrimea-Nauchnij in April 1967, nearly 3 years prior to its official discovery observation at Cerro El Roble.[1]
In theSDSS-based taxonomy,Spahr is a stonyS-type asteroid.[9]Pan-STARRS' survey also characterizes the body as an S-type,[5][10] while in both, the Tholen- and SMASS-like taxonomy of theSmall Solar System Objects Spectroscopic Survey (S3OS2),Spahr is an uncommonA-type asteroid.[4][11]
In December 2009, a first rotationallightcurve ofSpahr was obtained fromphotometric observations by French amateur astronomerRené Roy. Lightcurve analysis gave arotation period of 11.946 hours with a relatively high brightness amplitude of 0.47magnitude (U=3-).[5][8]
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Spahr measures between 5.919 and 6.032 kilometers in diameter and its surface has a highalbedo between 0.4044 and 0.419.[6][7] TheCollaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from8 Flora, the parent body of the Flora family – and consequently calculates a larger diameter of 6.51 kilometers using anabsolute magnitude of 13.1.[5]
Thisminor planet was named afterTimothy Bruce Spahr (born 1970), adiscoverer of minor planets andcomets such as171P/Spahr and242P/Spahr, as well as a co-discoverer ofCallirrhoe andAlbiorix (moon), satellites of Jupiter and Saturn, respectively. Spahr was with the photographicBigelow Sky Survey, which searched for high-latitude minor planets using the 0.41-m Catalina Schmidt telescope. (This survey was superseded by theCatalina Sky Survey). Spahr also headed theMinor Planet Center (MPC) from 2000 to 2014.[13] The asteroid's name was proposed by his MPC-collegesBrian Marsden,Gareth Williams andStephen Larson,[12] and published by the MPC on 3 May 1996 (M.P.C. 27124).[14]
