1080 Orchis
Main-belt asteroid
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1080 Orchis, provisional designation 1927 QB, is a dark background asteroid from the inner regions of the asteroid belt. It was discovered on 30 August 1927, by German astronomer Karl Reinmuth at the Heidelberg Observatory in southwest Germany.[18] The carbonaceous F-type asteroid has a rotation period of 16.1 hours and measures approximately 22 kilometers (14 miles) in diameter. It was named after the flowering plant Orchis.[3]
_Orchis.png)
Modelled shape of Orchis from its lightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | K. Reinmuth |
| Discovery site | Heidelberg Obs. |
| Discovery date | 30 August 1927 |
| Designations | |
| (1080) Orchis | |
| Pronunciation | /ˈɔːrkɪs/[2] |
Named after | Orchis (flowering plant)[3] |
| 1927 QB · 1955 DT A906 BH | |
| main-belt · (inner)[4] background[5] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 111.76 yr (40,821 days) |
| Aphelion | 3.0452 AU |
| Perihelion | 1.7924 AU |
| 2.4188 AU | |
| Eccentricity | 0.2590 |
| 3.76 yr (1,374 days) | |
| 278.54° | |
| 0° 15m 43.2s / day | |
| Inclination | 4.5873° |
| 2.0437° | |
| 57.028° | |
| Physical characteristics | |
| 20.755±8.470 km[6] 21.797±0.130 km[7] 21.86±0.26 km[8] 22.918±0.241 km[9] 23.28±1.7 km[4][10] 23.53±6.59 km[11] 24.62±6.75 km[12] | |
| 16.061±0.004 h[13] 16.0657±0.0005 h[14] 16.075±0.0207 h[15] 16.1±0.1 h[16] | |
Pole ecliptic latitude | |
| 0.029±0.002[7] 0.03±0.02[11] 0.031±0.032[12] 0.0331±0.0028[9] 0.0430±0.007[4][10] 0.0508±0.0499[6] 0.051±0.001[8] | |
| Tholen = F[1][4] B–V = 0.624[1] U–B = 0.206[1] | |
| 12.133±0.002 (R)[15] · 12.20[1][4][8][9][10][11] · 12.32[6] · 12.43[12] | |
Orbit and classification
Orchis is a non-family asteroid of the main belt's background population.[5] It orbits the Sun in the inner asteroid belt at a distance of 1.8–3.0 AU once every 3 years and 9 months (1,374 days; semi-major axis of 2.42 AU). Its orbit has an eccentricity of 0.26 and an inclination of 5° with respect to the ecliptic.[1] The asteroid was first observed as A906 BH at Heidelberg in January 1906. The body's observation arc begins with its official discovery observation in August 1927.[18]
Naming
This minor planet was named after the flowering plant Orchis, a genus in the orchid family. The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 102).[3]
Reinmuth's flowers
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 with 1054 Forsytia, that were all named after plants, in particular flowering plants (also see list of minor planets named after animals and plants).[19]
Physical characteristics
In the Tholen classification, Orchis is an uncommon F-type asteroid, a type which belongs to the wider C-complex of carbonaceous asteroids.[1][4]
Rotation period and poles
In 2010, three rotational lightcurves of Orchis were obtained from photometric observations. Lightcurve analysis gave a rotation period of 16.061, 16.075 and 16.1 hours with a brightness amplitude of between 0.23 and 0.31 magnitude (U=2+/2/3).[13][15][16] A modeled lightcurve based on optical data from a large collaboration network found a concurring period of 16.0657 hours and two spin axis of (255.0°, 27.0°) and (71.0°, 28.0°) in ecliptic coordinates (λ, β).[14]
Diameter and albedo
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Orchis measures between 20.755 and 24.62 kilometers in diameter and its surface has an albedo between 0.029 and 0.051.[6][7][8][9][10][11][12] The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.0430 and a diameter of 23.28 kilometers based on an absolute magnitude of 12.2.[4][10]
