| Discovery [1] | |
|---|---|
| Discovered by | E. Bowell |
| Discovery site | Lowell Obs. |
| Discovery date | 2 December 1981 |
| Designations | |
| (4276) Clifford | |
Named after | Clifford Cunningham(Canadian astronomer)[2] |
| 1981 XA | |
| Mars-crosser [1][3] · main belt | |
| Orbital characteristics [1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 35.67 yr (13,027 days) |
| Aphelion | 2.4195AU |
| Perihelion | 1.5994 AU |
| 2.0095 AU | |
| Eccentricity | 0.2041 |
| 2.85yr (1,040 days) | |
| 186.63° | |
| 0° 20m 45.6s / day | |
| Inclination | 21.033° |
| 76.881° | |
| 3.5494° | |
| Physical characteristics | |
| Dimensions | 4.441±1.128 km[4] |
| 0.142±0.107[4] | |
| SMASS =Cb [1] | |
| 14.6[1] | |
4276 Clifford, provisional designation1981 XA is anasteroid and sizableMars-crosser from the innermost region of theasteroid belt, approximately 4.4 kilometers in diameter. It was discovered on 2 December 1981, by American astronomersEdward Bowell atLowell Observatory in Flagstaff, United States. The asteroid was named in honor of astronomer and writerClifford Cunningham.[3]
Clifford is a member of the group of main-belt asteroids known asMars-crosser asteroids, specifically, it is listed as an Outer-grazer.[citation needed] It orbits the Sun at a distance of 1.6–2.4 AU once every 2 years and 10 months (1,040 days). Its orbit has aneccentricity of 0.20 and aninclination of 21° with respect to theecliptic.[1]
In theSMASS classification,Clifford is a Cb-type, which transitions from the carbonaceousC-type asteroids to the rareB-type asteroids.[1]
According to the survey carried out by NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Clifford measures 4.441 kilometers in diameter and its surface has analbedo of 0.142.[4] As of 2017, no rotationallightcurve has been obtained ofClifford. Itsrotation period and shape remain unknown.[5]
Thisminor planet was named after Canadian astronomer and authorClifford Cunningham, who is best known for his 1988 published bookIntroduction to Asteroids and 5-volume history of asteroid studies published by Springer in 2016 and 2017. He received his Ph.D. in the history of astronomy in 2015. His astronomical work includesastrometry andphotometry of minor planets.[2] The approved naming citation was published by theMinor Planet Center on 10 April 1990 (M.P.C. 16248).[6]
