_Numidia.png) Modelled shape ofNumidia from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | C. Jackson |
| Discovery site | Johannesburg Obs. |
| Discovery date | 30 April 1935 |
| Designations | |
| (1368) Numidia | |
| Pronunciation | /njuːˈmɪdiə/[2] |
Named after | Numidia[3] (ancient Berber kingdom) |
| 1935 HD · 1928 SN 1931 JF · 1935 KB 1936 QN · 1953 YK | |
| main-belt · (inner)[4] background[5] · Maria[6] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 86.45 yr (31,577 days) |
| Aphelion | 2.6814AU |
| Perihelion | 2.3673 AU |
| 2.5243 AU | |
| Eccentricity | 0.0622 |
| 4.01yr (1,465 days) | |
| 146.05° | |
| 0° 14m 44.52s / day | |
| Inclination | 14.823° |
| 18.130° | |
| 264.36° | |
| Physical characteristics | |
| Dimensions | 15.93±0.37 km[7] 19.24 km(derived)[4] 19.29±0.9 km[8] 19.591±0.213 km[9] 19.899±0.110 km[10] 20.66±0.82 km[11] |
| 3.64h[12] 3.640739 h[13] 3.640740 h[14] | |
| 0.177±0.016[11] 0.1838±0.0295[10] 0.1918(derived)[4] 0.2035±0.019[8] 0.298±0.021[7] | |
| S(assumed)[4] B–V = 0.860[1] U–B = 0.360[1] | |
| 10.92[1][7][8][11] · 10.99[4][10][12] | |
1368 Numidia, provisional designation1935 HD, is a stonybackground asteroid from the central regions of theasteroid belt, approximately 19 kilometers in diameter. It was discovered on 30 April 1935, by South African astronomerCyril Jackson at theUnion Observatory in Johannesburg.[15] The asteroid was named after the ancient North African kingdom ofNumidia.[3]
Based on thehierarchical clustering method,Numidia has both been classified as a non-family asteroid from the main belt'sbackground population (Nesvorný),[5] and as a core member of theMaria family (Milani and Knežević).[6] It orbits the Sun in theintermediate asteroid belt at a distance of 2.4–2.7 AU once every 4.01 years (1,465 days;semi-major axis of 2.52 AU). Its orbit has aneccentricity of 0.06 and aninclination of 15° with respect to theecliptic.[1]
The asteroid was first identified as1928 SN atUccle Observatory in September 1928. The body'sobservation arc begins at Johannesburg in May 1931, three weeks after its official discovery observation.[15]
Thisminor planet was named after the ancientBerber kingdom ofNumidia, that was located in North Africa, in what is now Algeria. The official naming citation was mentioned inThe Names of the Minor Planets byPaul Herget in 1955 (H 124).[3]
Numidia is an assumed stonyS-type asteroid.[4]
In May 1983, a first rotationallightcurve ofNumidia was obtained from photometric observations by American astronomerRichard Binzel. Lightcurve analysis gave a well-definedrotation period of 3.64 hours with a brightness amplitude of 0.35magnitude (U=3).[12]
Modeling of the asteroid's lightcurve gave a concurring sidereal period of 3.640739 and 3.640740 hours, respectively.[13][14] In 2016, modeling also determined a pole of (201.0°, −62.0°) inecliptic coordinates (λ, β).[13]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Numidia measures between 15.93 and 20.66 kilometers in diameter and its surface has analbedo between 0.177 and 0.298.[7][8][9][10][11]
TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.1918 and a diameter of 19.24 kilometers based on anabsolute magnitude of 10.99.[4]
