_Thomana.png) Shape model ofThomana from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | K. Reinmuth |
| Discovery site | Heidelberg Obs. |
| Discovery date | 25 June 1924 |
| Designations | |
| (1023) Thomana | |
Named after | St. Thomas Choir of Leipzig (Germanboys' choir)[2] |
| 1924 RU · 1936 RG | |
| main-belt · (outer)[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 92.86 yr (33,916 days) |
| Aphelion | 3.4893AU |
| Perihelion | 2.8442 AU |
| 3.1667 AU | |
| Eccentricity | 0.1019 |
| 5.64yr (2,058 days) | |
| 107.00° | |
| 0° 10m 29.64s / day | |
| Inclination | 10.078° |
| 194.32° | |
| 194.19° | |
| Physical characteristics | |
| Dimensions | 53.28±20.25 km[4] 58.27±1.6 km(IRAS:11)[5] 61.02±1.00 km[6] 61.34±4.17 km[7] |
| 17.56±0.05 h[8] 17.56±0.01 h[9] 17.561±0.007h[8] 17.5611±0.0005 h[10] | |
| 0.05±0.05[4] 0.059±0.012[7] 0.060±0.002[6] 0.0649±0.004(IRAS:11)[5] | |
| Tholen =G[1] · G[3] B–V = 0.764[1] U–B = 0.493[1] | |
| 9.76[1][3][5][6][7] · 9.99[4] · 10.26±0.57[11] | |
1023 Thomana, provisional designation1924 RU, is a rare-type carbonaceousbackground asteroid from the outer regions of theasteroid belt, approximately 58 kilometers in diameter. It was discovered on 25 June 1924, by German astronomerKarl Reinmuth atHeidelberg Observatory in southwest Germany. The asteroid was named after theSt. Thomas Choir of Leipzig.[12]
Thomana orbits the Sun in theouter main-belt at a distance of 2.8–3.5 AU once every 5 years and 8 months (2,058 days). Its orbit has aneccentricity of 0.10 and aninclination of 10° with respect to theecliptic.[1] The asteroid'sobservation arc begins at Heidelberg, one night after its official discovery observation.[12]
In theTholen classification,Thomana is an uncommon carbonaceousG-type asteroid.[1]
Between 2006 and 2009, three rotationallightcurves ofThomana were obtained from photometric observations by astronomers James W. Brinsfield,Pierre Antonini as well asRené Roy andLaurent Bernasconi. Lightcurve analysis gave a concurringrotation period of 17.56 hours with a brightness variation between 0.27 and 0.36magnitude (U=2/2/3-).[8][9]
In 2016, an international study modeled a lightcurve from various data sources with a period of 17.5611 hours and found twospin axis of (86.0°, −65.0°) and (272.0°, −42.0°), respectively, inecliptic coordinates (λ, β) (Q=n.a.).[10]
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,Thomana measures between 53.28 and 61.34 kilometers in diameter and its surface has analbedo between 0.05 and 0.065.[4][5][6][7] TheCollaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is an albedo of 0.0649 and a diameter of 58.27 kilometers based on anabsolute magnitude of 9.76.[3]
Thisminor planet was named by the discoverer after theSt. Thomas Choir of Leipzig ("Thomanerchor"), aboys' choir atSt. Thomas Church in Leipzig, Germany, whereJohann Sebastian Bach used to work as music director. The official naming citation was published byPaul Herget inThe Names of the Minor Planets in 1955 (H 98;LDS).[2]
