_Turnera.png) Shape model ofTurnera from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | C. Jackson |
| Discovery site | Johannesburg Obs. |
| Discovery date | 1 August 1929 |
| Designations | |
| (1186) Turnera | |
Named after | Herbert Hall Turner (British astronomer)[2] |
| 1929 PL · 1930 UO 1930 WL · 1932 CC A919 SE | |
| main-belt · (outer) Eos[3][4] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 87.93 yr (32,115 days) |
| Aphelion | 3.3314AU |
| Perihelion | 2.7190 AU |
| 3.0252 AU | |
| Eccentricity | 0.1012 |
| 5.26yr (1,922 days) | |
| 252.20° | |
| 0° 11m 14.28s / day | |
| Inclination | 10.752° |
| 42.988° | |
| 295.00° | |
| Physical characteristics | |
| Dimensions | 34.290±0.275 km[5] 35.56±2.0 km[6] 37.17±7.78 km[7] 39.06±0.57 km[8] 39.19±1.25 km[9] 39.691±0.354 km[10] |
| 12.010h[11] 12.066±0.004 h[12][a] 12.085±0.001 h[13] 15±2 h[14] | |
| 0.12±0.04[7] 0.2350±0.0371[10] 0.240±0.026[9] 0.247±0.008[8] 0.2919±0.036[6] | |
| S(Tholen)[1] · S[3] Sq(SMASS)[1] B–V = 0.790[3] U–B = 0.430[3] | |
| 9.20[1][3][6][7][8][9][10] 9.90±0.38[15] | |
1186 Turnera, provisional designation1929 PL, is a stony Eoanasteroid from the outer regions of theasteroid belt, approximately 36 kilometers in diameter. It was discovered on 1 August 1929, by South African astronomerCyril Jackson at theUnion Observatory in Johannesburg.[16] The asteroid was later named after British astronomerHerbert Hall Turner.[2]
Turnera is a member of theEos family (606), the largestasteroid family in theouter main-belt with nearly 10,000 known members.[4][17]: 23 It orbits the Sun at a distance of 2.7–3.3 AU once every 5 years and 3 months (1,922 days). Its orbit has aneccentricity of 0.10 and aninclination of 11° with respect to theecliptic.[1]Turnera was first identified as1919 SE atSimeiz Observatory in September 1919. This observation, however, remains unused and the body'sobservation arc begins at Johannesburg with its official discovery observation in 1929.[16]
In theTholen classification,Turnera is a common, stonyS-type asteroid. In theSMASS classification, it is a Sq-type that transitions to theQ-type asteroids.[1] Generically, Eoan asteroids are also characterized asK-type asteroids with analbedo of 0.13.[17]: 23
In January 2016, the best-rated rotationallightcurve ofTurnera was obtained from photometric observations by the Spanish amateur astronomer group OBAS,Observadores de Asteroids. Lightcurve analysis gave a well-definedrotation period of 12.085 hours with a brightness variation of 0.31magnitude (U=3).[13] Previously, American astronomerBrian Warner obtained a similar period of 12.066 hours and an amplitude of 0.34magnitude at his Palmer Divide Observatory (716) in Colorado (U=2+).[12][a]
Other lightcurve observations were made by French amateur astronomerLaurent Bernasconi (15±2 hours; Δmag of 0.25;U=2+) in February 2006,[14] and by Italian astronomerMaria A. Barucci (12.010 hours; Δmag of 0.20;U=2) in August 1987.[11]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite, and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Turnera measures between 34.290 and 39.691 kilometers in diameter and its surface has analbedo between 0.12 and 0.2919.[5][6][7][8][9][10]
TheCollaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.2919 and a diameter of 35.56 kilometers with anabsolute magnitude of 9.20.[3]
Thisminor planet was named after British astronomerHerbert Hall Turner (1861–1930), director of theRadcliffe Observatory atUniversity of Oxford.[2] He is also credited with coining the term "parsec". The official naming citation was published inPaul Herget'sThe Names of the Minor Planets in 1955 (H 110).[2]
