| Discovery[1] | |
|---|---|
| Discovered by | L. Oterma |
| Discovery site | Turku Obs. |
| Discovery date | 15 October 1941 |
| Designations | |
| (1695) Walbeck | |
Named after | Henrik Walbeck(geodesist)[2] |
| 1941 UO · 1964 QA 1964 RE | |
| main-belt · (middle)[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 75.44 yr (27,554 days) |
| Aphelion | 3.5921AU |
| Perihelion | 1.9703 AU |
| 2.7812 AU | |
| Eccentricity | 0.2916 |
| 4.64yr (1,694 days) | |
| 141.65° | |
| 0° 12m 45s / day | |
| Inclination | 16.705° |
| 218.46° | |
| 139.42° | |
| Physical characteristics | |
| Dimensions | 17.88±0.27 km[4] 18.953±0.258 km[5][6] 19.60 km(derived)[3] 19.62±0.8 km[7] 19.84±0.29 km[8] |
| 5.16±0.05 h[9] 5.1607±0.0006 h[9] 5.3h[10] | |
| 0.037±0.007[4] 0.042±0.006[6] 0.0425±0.0058[5] 0.0460(derived)[3] 0.0504±0.005[7] 0.051±0.002[8] | |
| SMASS = Cg[1] · C[3] | |
| 12.4[5][7][8] · 12.5[1][3] · 12.76±0.23[11] · 12.93[4] | |
1695 Walbeck, provisional designation1941 UO, is a carbonaceousasteroid from the central region of theasteroid belt, approximately 19 kilometers in diameter. It was discovered on 15 October 1941, by Finnish astronomerLiisi Oterma atTurku Observatory in Southwest Finland, and named afterHenrik Walbeck.[2][12]
The asteroid orbits the Sun in thecentral main-belt at a distance of 2.0–3.6 AU once every 4 years and 8 months (1,694 days). Its orbit has aneccentricity of 0.29 and aninclination of 17° with respect to theecliptic.[1]Walbeck'sobservation arc begins the night after its official discovery observation.[12]
In theSMASS taxonomy, the carbonaceous asteroid is characterized as a Cg-type, an intermediate between theC-type andG-type asteroids.[1]
In November 2006, a rotationallightcurve ofWalbeck was obtained from photometric observations by French amateur astronomerPierre Antonini. It gave arotation period of 5.1607 hours with a brightness variation of 0.22magnitude (U=3).[9] Two similar periods were obtained byDavid Romeuf and by a team of Hungarian astronomers (U=2/2).[9][10]
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,Walbeck measures between 17.88 and 19.62 kilometers in diameter and its surface has analbedo between 0.037 and 0.051.[4][5][7][8] TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.046 and a diameter of 19.60 kilometers based on an absolute magnitude of 12.5.[3]
Theminor planet was named in memory of Finnish scientistHenrik Johan Walbeck (1793–1822), astronomer andgeodesist at the oldAcademia Aboensis who used the method of least squares to derive a good value for the Earth's flattening.[2] The official naming citation was published by theMinor Planet Center on 1 April 1980 (M.P.C. 5281).[13]
