_Ulrike.png) Modelled shape ofUlrike from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | S. Belyavskyj |
| Discovery site | Simeiz Obs. |
| Discovery date | 23 September 1917 |
| Designations | |
| (885) Ulrike | |
Named after | Ulrike von Levetzow[2] (friend and love ofGoethe) |
| 1917 CX · 1933 QQ 1934 XL · A906 SE 1917 CX · 1906 SE | |
| main-belt[1][3] · (outer) background[4] · Themis[5] | |
| Orbital characteristics[3] | |
| Epoch 31 May 2020 (JD 2459000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 112.98yr (41,267 d) |
| Aphelion | 3.6720AU |
| Perihelion | 2.5253 AU |
| 3.0987 AU | |
| Eccentricity | 0.1850 |
| 5.45 yr (1,992 d) | |
| 318.39° | |
| 0° 10m 50.52s / day | |
| Inclination | 3.3056° |
| 148.90° | |
| 203.78° | |
| Physical characteristics | |
| 4.90±0.05 h[9][10] | |
| C(assumed)[9] | |
| 10.7[1][3][7][8] | |
885 Ulrike (prov. designation:A917 SVor1917 CX) is an elongatedThemistian asteroid from the outer regions of theasteroid belt. It was discovered on 23 September 1917, by Soviet astronomerSergey Belyavsky at theSimeiz Observatory on the Crimean peninsula.[1] The presumedC-type asteroid has a shortrotation period of 4.9 hours and measures approximately 33 kilometers (21 miles) in diameter. It was likely named afterUlrike von Levetzow, last love ofGoethe.[2]
When applying the synthetichierarchical clustering method (HCM) byZappalà,Milani andKnežević (AstDys),Ulrike is a core member of theThemis family (602), a largeasteroid family of carbonaceous asteroids named after24 Themis. However, according to another HCM-analysis byNesvorný, it is abackground asteroid.[4][5][12]: 23 It orbits the Sun in theouter main-belt at a distance of 2.5–3.7 AU once every 5 years and 5 months (1,992 days;semi-major axis of 3.1 AU). Its orbit has aneccentricity of 0.19 and aninclination of 3° with respect to theecliptic.[3] The asteroid was first observed atLowell Observatory in August 1906. The body'sobservation arc begins atHeidelberg Observatory on 27 September 1906, more than a decade prior to its official discovery observation at Simeiz.[1]
Thisminor planet was allegedly named afterUlrike von Levetzow (1804–1899), a friend and last love of the German poetJohann Wolfgang von Goethe, who met Ulrike during summertime 1821–1823 in Marienbad, Bohemia.[2] After she declined to marry him, Goethe started writingMarienbad Elegy, one of his finest poems.Lutz Schmadel, the author of theDictionary of Minor Planet Names, considers this interpretation the most likely because the discoverer, who studied at Göttingen University, was an expert in German literature.[2]
Ulrike'spectral type is unknown. It is an assumed carbonaceousC-type asteroid,[9] which agrees with the overall spectral type assigned to members of theThemis family.[12]: 23
In September 2010, a rotationallightcurve ofUlrike was obtained fromphotometric observations by John Menke at the Menke Observatory. Lightcurve analysis gave arotation period of4.90±0.05 hours with a high brightness variation of0.55±0.05magnitude, indicative of an elongated shape (U=3).[9][10] An alternative period determination of4.9268±0.0002 hours with an even higher amplitude of0.72±0.12 was made byLaurent Bernasconi one month later in October 2010 (U=2).[13] A modeled lightcurve using photometric data from theLowell Photometric Database gave a sidereal period of4.906164±0.000001 and twospin axes at (13.0°, −64.0°) and (207.0°, −60.0°) inecliptic coordinates (λ, β).[11]
According to the survey carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite, and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer (WISE),Ulrike measures (30.537±0.756), (33.43±5.3) and (44.69±1.06) kilometers in diameter and its surface has analbedo of (0.109±0.025), (0.083±0.034) and (0.047±0.003), respectively.[6][7][8] TheCollaborative Asteroid Lightcurve Link adopts the results from IRAS, that is an albedo of 0.083 and a diameter of 33.43 kilometers based on anabsolute magnitude of 10.7.[9] The WISE team also published an alternative mean-diameter of (42.20±14.76 km) with an albedo of (0.08±0.06).[4][9]
