| Discovery[1] | |
|---|---|
| Discovered by | P. Wild |
| Discovery site | Zimmerwald Obs. |
| Discovery date | 30 October 1972 |
| Designations | |
| (1844) Susilva | |
Named after | Susi Petit–Pierre (friend of discoverer)[2] |
| 1972 UB · 1943 EU 1953 AA · 1959 GJ | |
| main-belt · Eos[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 64.40 yr (23,521 days) |
| Aphelion | 3.1714AU |
| Perihelion | 2.8587 AU |
| 3.0150 AU | |
| Eccentricity | 0.0518 |
| 5.24yr (1,912 days) | |
| 70.711° | |
| 0° 11m 17.88s / day | |
| Inclination | 11.788° |
| 99.365° | |
| 73.564° | |
| Physical characteristics | |
| Dimensions | 19.022±0.232 km[4] 22.41 km(calculated)[3] 26.800±0.321 km[5] |
| 0.118±0.011[5] 0.14(assumed)[3] 0.2358±0.0545[4] | |
| S[3] | |
| 10.8[4][5] · 11.0[1][3] · 11.49±0.44[6] | |
1844 Susilva, provisional designation1972 UB, is a stony Eoanasteroid from the outer region of theasteroid belt, approximately 22 kilometers in diameter. It was discovered on 30 October 1972, by Swiss astronomerPaul Wild atZimmerwald Observatory near Bern, Switzerland, and later named after a schoolfriend of the discoverer.[2][7]
Susilva is a member of theEos family, a collisional group of more than 4,000 asteroids, which are well known for mostly being ofsilicaceous composition. It orbits the Sun in theouter main-belt at a distance of 2.9–3.2 AU once every 5 years and 3 months (1,912 days). Its orbit has aneccentricity of 0.05 and aninclination of 12° with respect to theecliptic.[1]First identified as1943 EU atTurku Observatory,Susilva's first used observation was taken atUccle Observatory in 1953, extending the body'sobservation arc by 19 years prior to its official discovery observation.[7]
According to the survey carried out by NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission, the asteroid measures between 19.0 and 26.8 kilometers in diameter, and its surface has analbedo of 0.118 to 0.236.[4][5] TheCollaborative Asteroid Lightcurve Link assumes an albedo of 0.14, taken from221 Eos, the family's largest member and namesake – and calculates a diameter of 22.4 kilometers based on an absolutemagnitude of 11.0.[3]Susilva'srotation period has not yet been measured.[3]
The discoverer named a pair of asteroids after two of his former schoolmates, Susi and Helen, both from the small village ofWald, Zürich in Switzerland. This one was dedicated to Susi Petit–Pierre, while the subsequently numbered asteroid,1845 Helewalda, was given to Helen Gachnang.[2][8] The officialnaming citation was published by theMinor Planet Center on 18 April 1977 (M.P.C. 4156).[9]
Helen Gachnang and Susi Petit-Pierre visit the Eschenberg Observatory
