_Siva.png) Modelled shape ofSiva from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | E. Delporte |
| Discovery site | Uccle Obs. |
| Discovery date | 29 September 1930 |
| Designations | |
| (1170) Siva | |
Named after | Shiva(Hindu deity)[2] |
| 1930 SQ | |
| Mars-crosser[3][4] Phocaea[5] | |
| Orbital characteristics[1] | |
| Epoch 16 February 2017 (JD 2457800.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 85.19 yr (31,116 days) |
| Aphelion | 3.0245AU |
| Perihelion | 1.6291 AU |
| 2.3268 AU | |
| Eccentricity | 0.2998 |
| 3.55yr (1,296 days) | |
| 94.741° | |
| 0° 16m 39.72s / day | |
| Inclination | 22.184° |
| 0.9218° | |
| 59.391° | |
| Earth MOID | 0.7263 AU |
| Mars MOID | 0.3760 AU |
| Physical characteristics | |
| Dimensions | 7.68±2.18 km[6] 10.37±0.8 km(IRAS:2)[7] 12.13±0.89 km[8] |
| 3.5h[9] 4.98 h[a] 5.22±0.01 h[10] | |
| 0.128±0.020[8] 0.1751±0.032(IRAS:2)[7] 0.40±0.16[6] | |
| B–V = 0.864[1] U–B = 0.452[1] Tholen =S[1] · S[3][11] | |
| 12.00[11] · 12.18[6] · 12.43[1][3][7][8] | |
1170 Siva, provisional designation1930 SQ, is a stonyPhocaea asteroid and largeMars-crosser from the innermost regions of theasteroid belt, approximately 10 kilometers in diameter. It was discovered on 29 September 1930, by Belgian astronomerEugène Delporte atUccle Observatory in Belgium, and later named after the Hindu deityShiva.[2][4]
Siva is aMars-crossing asteroid, as it crosses the orbit of Mars at 1.666 AU. It is also a member of thePhocaea family (701).[5] It orbits the Sun at a distance of 1.6–3.0 AU once every 3 years and 7 months (1,296 days). Its orbit has aneccentricity of 0.30 and aninclination of 22° with respect to theecliptic.[1]Siva was first observed at the JapaneseKwasan Observatory, 3 days prior to is discovery. The body'sobservation arc begins at Uccle, two weeks after its official discovery observation.[4]
Thisminor planet is named afterShiva, a Hindu deity often depicted with a third eye on his forehead and with a snake around his neck.[2] Naming citation was first mentioned inThe Names of the Minor Planets byPaul Herget in 1955 (H 109).[2]
In theTholen taxonomy,Siva is a stonyS-type asteroid.[1]
Only fragmentarylightcurves ofSiva have been obtained since 2001. They gave arotation period between 3.5 and 5.22 hours with a small change in brightness of 0.04 to 0.1magnitude (U=1/n.a./1).[9][10][a] As of 2017, no secure period has been published.[3]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite, and NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Siva measures between 7.68 and 12.13 kilometers in diameter, and its surface has analbedo between 0.128 and 0.40.[6][7][8] TheCollaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.1751 and a diameter of 10.37 kilometers with anabsolute magnitude of 12.43.[3]Siva belongs to the brightest known Mars-crossers.[12]
