_Reinmuthia.png) Shape model of Reinmuthia from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | K. Reinmuth |
| Discovery site | Heidelberg Obs. |
| Discovery date | 11 February 1927 |
| Designations | |
| (1111) Reinmuthia | |
Named after | Karl Reinmuth[2] (the discoverer) |
| 1927 CO · 1929 QG | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 90.72 yr (33,137 days) |
| Aphelion | 3.2947AU |
| Perihelion | 2.6911 AU |
| 2.9929 AU | |
| Eccentricity | 0.1008 |
| 5.18yr (1,891 days) | |
| 329.12° | |
| 0° 11m 25.44s / day | |
| Inclination | 3.8917° |
| 132.44° | |
| 236.17° | |
| Physical characteristics | |
| 24.38±0.48 km[6] 41.26 km(derived)[7] | |
| 4.00742±0.00005 h[8] 4.007347 h[9] 4.00750±0.00003 h[8] 4.0075±0.0001 h[10][a] 4.02 h[11] | |
| 0.057(assumed)[7] 0.167±0.008[6] | |
| Tholen =FXU:[1][7] B–V =0.639±0.016[1] U–B =0.230±0.030[1] | |
| 10.65[7][11] · 10.67[1][6] | |
1111 Reinmuthia (provisional designation:1927 CO) is a very elongatedasteroid from thebackground population, located in the outer region of theasteroid belt. It was discovered on 11 February 1927, by German astronomerKarl Reinmuth at theHeidelberg Observatory in southwest Germany.[3] TheF-type asteroid (FX) has a shortrotation period of 4.02 hours and measures approximately 40 kilometers (25 miles) in diameter.[7] It was later named in honor of Karl Reinmuth, the discoverer himself.[2]
Reinmuthia is a non-family asteroid of the main belt'sbackground population when applying thehierarchical clustering method to itsproper orbital elements.[4][5] It orbits the Sun in theouter asteroid belt at a distance of 2.7–3.3 AU once every 5 years and 2 months (1,891 days;semi-major axis of 2.99 AU). Its orbit has aneccentricity of 0.10 and aninclination of 4° with respect to theecliptic.[1] The body'sobservation arc begins at Heidelberg with its official discovery observation.[3]
Thisminor planet was named after its discoverer,Karl Reinmuth (1892–1979), a German astronomer at the Heidelberg-Königstuhl State Observatory and a prolificdiscoverer of minor planets. In total, hediscovered 395 asteroids, most of them during the 1920s and 1930s, which was a unique record for many years. His discoveries include1862 Apollo and69230 Hermes, twolost asteroids andnear-Earth objects as well as several largeJupiter trojans. His 1931-discovered asteroid(11435) 1931 UB is the oldest discovered yet still unnamed asteroid. The official naming citation was mentioned inThe Names of the Minor Planets byPaul Herget in 1955 (H 104).[2]
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In theTholen classification, Reinmuthia has an ambiguousspectral type, closest to that of a darkF-type and somewhat similar to anX-type asteroid. The spectrum had also been flagged as "unusual" and "nosy" byTholen (FXU:).[1]
Rotationallightcurves of Reinmuthia have been obtained from photometric observations by American astronomerRichard Binzel as well as by Hiromi and Hiroko Hamanowa at the Hamanowa Astronomical Observatory (D91) in Japan (U=3/3/3).[8][10][11] Lightcurve analysis gave a consolidated, well-definedrotation period of 4.02 hours with a high brightness amplitude between 0.61 and 0.95magnitude (U=3).[7][a]
Lightcurve inversion also modeled the body's shape andpoles. In 2013, modelling by an international study using photometric data from theUS Naval Observatory, the Uppsala Asteroid Photometric Catalogue, thePalomar Transient Factory and theCatalina Sky Survey gave a similar sidereal period of 4.007347 hours and two spin axes of (356.0°, 68.0°) and (153.0°, 78.0°) inecliptic coordinates (λ, β). The body's very elongated shape had already been indicated by the high brightness variation measured during the photometric observations.[9]
According to the survey carried out by the JapaneseAkari satellite, Reinmuthia measures 24.38 kilometers in diameter and its surface has analbedo of 0.167.[6] TheCollaborative Asteroid Lightcurve Link assumes a standard albedo forcarbonaceous asteroids of 0.057 and derives a diameter of 41.26 kilometers based on anabsolute magnitude of 10.65.[7]
