_Tha%25C3%25AFs.png) Modelled shape ofThaïs from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | G. Neujmin |
| Discovery site | Simeiz Obs. |
| Discovery date | 6 November 1931 |
| Designations | |
| (1236) Thaïs | |
| Pronunciation | /ˈθeɪ.ɪs/[2] |
Named after | Thaïs(ancient Greekhetaira)[3] |
| 1931 VX · 1957 LQ 1964 JH · 1965 WA | |
| Orbital characteristics[1] | |
| Epoch 16 February 2017 (JD 2457800.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 84.57 yr (30,888 days) |
| Aphelion | 3.0192AU |
| Perihelion | 1.8455 AU |
| 2.4323 AU | |
| Eccentricity | 0.2413 |
| 3.79yr (1,386 days) | |
| 216.42° | |
| 0° 15m 35.28s / day | |
| Inclination | 13.169° |
| 48.618° | |
| 305.94° | |
| Physical characteristics | |
| 14.43±4.75 km[7] 17.18±4.94 km[8] 19.163±1.790 km[9] 20.07±0.41 km[10] 22.34±1.3 km(IRAS:7)[11] | |
| 72 h[12] | |
| 0.0599±0.007(IRAS:7)[11] 0.075±0.004[10] 0.0813±0.0159[9] 0.10±0.07[8] 0.11±0.11[7] | |
| Tholen =T[1][13] B–V = 0.785[1] U–B = 0.383[1] | |
| 11.91[8] 11.93[1][13][7][9][10][11] | |
1236 Thaïs/ˈθeɪ.ɪs/ (prov. designation:1931 VX) is a darkbackground asteroid from the inner regions of theasteroid belt. The rareT-type asteroid has a notably longrotation period of 72 hours and measures approximately 18 kilometers (11 miles). It was discovered on 6 November 1931, by Soviet astronomerGrigory Neujmin atSimeiz Observatory on the Crimean peninsula, and named after the ancient Greek prostituteThaïs.[3][4]
Thaïs is a non-family asteroid of the main belt'sbackground population when applying thehierarchical clustering method to itsproper orbital elements.[5][6] It orbits the Sun in theinner main-belt at a distance of 1.8–3.0 AU once every 3 years and 9 months (1,386 days). Its orbit has aneccentricity of 0.24 and aninclination of 13° with respect to theecliptic.[1] The body'sobservation arc begins at the discovering observatory, one month after its official discovery observation, as noprecoveries were taken, and no prior identifications were made.[4]
Thisminor planet was named afterThaïs, the famous Greekhetaera (ancient prostitute), who lived during the time ofAlexander the Great (356–323 BC) and accompanied him on his campaigns. It is also the name of the protagonist in the novelThaïs by French poetAnatole France.[3]
Thaïs is a dark and reddishT-type asteroid in theTholen taxonomic scheme.[1] It has also been classified as aL-type asteroid byPanSTARRS large-scale survey.[13]
As of 2017, the only existinglightcurve ofThaïs gives arotation period of 72 hours with a brightness variation of 0.08magnitude (U=1). The fragmentary light curve was obtained by Austrian astronomers from photoelectric observations in the early 1980s.[12] While not being aslow rotator, it has a significantly longer-than average rotation period, if future observations confirm the tentative results.
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,Thaïs measures between 14.43 and 22.34 kilometers in diameter, and its surface has analbedo between 0.06 and 0.11.[7][8][9][10][11] TheCollaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.0599 and a diameter of 22.34 kilometers based on anabsolute magnitude of 11.93.[13]
