1187 Afra
Main-belt asteroid
From Wikipedia, the free encyclopedia
1187 Afra (prov. designation: 1929 XC) is a dark background asteroid from the central regions of the asteroid belt. It was discovered by German astronomer Karl Reinmuth at Heidelberg Observatory on 6 December 1929.[1] The X-type asteroid has a rotation period of 14.1 hours and measures approximately 32 kilometers (20 miles) in diameter. The origin of the asteroid's name remains unknown.
_Afra.png)
Modelled shape of Afra from its lightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | K. Reinmuth |
| Discovery site | Heidelberg Obs. |
| Discovery date | 6 December 1929 |
| Designations | |
| (1187) Afra | |
Named after | unknown[2] |
| 1929 XC | |
| Orbital characteristics[3] | |
| Epoch 31 May 2020 (JD 2459000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 90.16 yr (32,932 d) |
| Aphelion | 3.2285 AU |
| Perihelion | 2.0523 AU |
| 2.6404 AU | |
| Eccentricity | 0.2227 |
| 4.29 yr (1,567 d) | |
| 52.040° | |
| 0° 13m 46.92s / day | |
| Inclination | 10.697° |
| 327.16° | |
| 74.956° | |
| Physical characteristics | |
| SMASS = X[3] | |
| 11.50[1][3] | |
Orbit and classification
Afra is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements.[4][5] It orbits the Sun in the central asteroid belt at a distance of 2.1â3.2 AU once every 4 years and 3 months (1,567 days; semi-major axis of 2.64 AU). Its orbit has an eccentricity of 0.22 and an inclination of 11° with respect to the ecliptic.[3] The body's observation arc begins at Heidelberg in January 1930, seven weeks after its official discovery observation.[1]
Naming
It is not known to what person, group of persons, or occurrence the name "Afra" refers to.[2]
Unknown meaning
Among the many thousands of named minor planets, Afra is one of 120 asteroids, for which no official naming citation has been published. All of these low-numbered asteroids have numbers between 164 Eva and 1514 Ricouxa and were discovered between 1876 and the 1930s, predominantly by astronomers Auguste Charlois, Johann Palisa, Max Wolf and Karl Reinmuth.[13]
Physical characteristics
The lightcurve of Afra shows a periodicity of 14.09±0.02 hours, during which time the brightness of the object varies by 0.40±0.02 in magnitude.[11][14]
