| Discovery[1] | |
|---|---|
| Discovered by | K. Reinmuth |
| Discovery site | Heidelberg Obs. |
| Discovery date | 10 October 1931 |
| Designations | |
| (1233) Kobresia | |
| Pronunciation | /koʊˈbriːziə/[2] |
Named after | Kobresia(flowering plant)[3] |
| 1931 TG2 · 1927 TB 1951 QJ · 1951 RP1 1954 EG | |
| main-belt · (inner)[4] background[5] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 90.15 yr (32,928 days) |
| Aphelion | 2.6976AU |
| Perihelion | 2.4143 AU |
| 2.5560 AU | |
| Eccentricity | 0.0554 |
| 4.09yr (1,493 days) | |
| 117.22° | |
| 0° 14m 28.32s / day | |
| Inclination | 5.6024° |
| 291.43° | |
| 335.02° | |
| Physical characteristics | |
| Dimensions | 29.73±7.16 km[6] 30.239±10.28 km[7] 31.46±15.67 km[8] 33.323±0.159 km[9] 33.45 km(derived)[4] 33.50±0.8 km[10] 36.06±0.60 km[11] 36.167±0.249 km[12] |
| 27.76±0.05h[13] 27.83±0.01 h[13] | |
| 0.0305±0.0420[7] 0.0396(derived)[4] 0.040±0.008[9] 0.04±0.02[6] 0.04±0.08[8] 0.0408±0.0074[12] 0.041±0.002[11] 0.047±0.007[14] 0.0475±0.002[10] | |
| C[15] · S(assumed)[4] | |
| 11.30[10][11][12] · 11.50[1][4][6][9] · 11.57[8] · 11.91[7] · 11.91±1.30[15] | |
1233 Kobresia, provisional designation1931 TG2, is a carbonaceous backgroundasteroid from the central regions of theasteroid belt, approximately 33 kilometers in diameter. It was discovered on 10 October 1931, by German astronomerKarl Reinmuth at theHeidelberg Observatory in southwest Germany.[16] The asteroid was named for the grass-like flowering plantKobresia, a genus in the sedge family.[3]
Kobresia is a non-family asteroid from the main belt'sbackground population.[5] It orbits the Sun in thecentral main-belt at a distance of 2.4–2.7 AU once every 4 years and 1 month (1,493 days;semi-major axis of 2.56 AU). Its orbit has aneccentricity of 0.06 and aninclination of 6° with respect to theecliptic.[1]
The body'sobservation arc begins with its first observation as1927 TB at Heidelberg in October 1927, or four years prior to its official discovery observation.[16]
Kobresia has been characterized as a carbonaceousC-type asteroid byPan-STARRS photometric survey.[15]
Two rotationallightcurves ofKobresia were obtained by French amateur astronomerPierre Antonini. Lightcurve analysis of his photometric observations made in 2004 and 2006, gave arotation period of 27.76 and 27.83 hours with a brightness amplitude of 0.32 and 0.34magnitude, respectively (U=2/2).[13] While not being aslow rotator,Kobresia's period is longer than that of the average asteroid.
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Kobresia measures between 29.73 and 36.167 kilometers in diameter and its surface has analbedo between 0.0305 and 0.0475.[6][7][8][9][10][11][12][14]
TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.0396 and a diameter of 33.45 kilometers based on anabsolute magnitude of 11.5.[4]
Thisminor planet was named after a genus in the familyCyperaceae,Kobresia, a grass-like flowering plant, commonly known as "bog sedges". The author of theDictionary of Minor Planet Names contacted Dutch astronomerIngrid van Houten-Groeneveld in order to confirm the meaning of this asteroid's name.[3]
The initials of the minor planets(1227) through(1234), all discovered by Reinmuth, spell out "G. Stracke".Gustav Stracke was a German astronomer and orbit computer, who had asked that no planet be named after him. In this manner Reinmuth was able to honour the man whilst honoring his wish. Nevertheless, Reinmuth directly honored Stracke by naming planet1019 Strackea later on.[17] The astronomerBrian Marsden was honored by the same type of meta-naming using consecutive initial letters in 1995, spelling out "Brian M." in the sequence of minor planets(5694) through(5699).[17]
Due to his many discoveries,Karl Reinmuth submitted a large list of 66 newly named asteroids in the early 1930s. The list covered his discoveries with numbers between(1009) and(1200). This list also contained a sequence of 28 asteroids, starting with1054 Forsytia, that were all named after plants, in particularflowering plants(also see list of minor planets named after animals and plants).[18]
