| Discovery[1] | |
|---|---|
| Discovered by | P. Wild |
| Discovery site | Zimmerwald Obs. |
| Discovery date | 13 May 1969 |
| Designations | |
| (1775) Zimmerwald | |
Named after | Zimmerwald (village; observatory)[2] |
| 1969 JA · 1952 HB2 1952 HD · 1953 TE2 | |
| main-belt · Eunomia[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 67.20 yr (24,545 days) |
| Aphelion | 3.0866AU |
| Perihelion | 2.1182 AU |
| 2.6024 AU | |
| Eccentricity | 0.1861 |
| 4.20yr (1,533 days) | |
| 148.54° | |
| 0° 14m 5.28s / day | |
| Inclination | 12.555° |
| 195.94° | |
| 84.725° | |
| Physical characteristics | |
| Dimensions | 10.17±0.69 km[4] 10.232±0.088 km[5][6] 10.70±2.19 km[7] 11.03 km(calculated)[3] |
| 122±5h[8] | |
| 0.21(assumed)[3] 0.21±0.09[7] 0.244±0.041[5][6] 0.247±0.035[4] | |
| S[3] | |
| 12.08±0.31[9] · 12.1[1][3][4][5] · 12.26[7] | |
1775 Zimmerwald, provisional designation1969 JA, is a stony Eunomianasteroid andslow rotator from the middle region of theasteroid belt, approximately 10 kilometers in diameter. It was discovered on 13 May 1969, by Swiss astronomerPaul Wild atZimmerwald Observatory near Bern, Switzerland.[10] It is named for the village ofZimmerwald, where the discovering observatory is located.[2]
Zimmerwald is a member of theEunomia family, a large group of mostly stonyS-type asteroids and the most prominent family in the intermediate main-belt, which is located between two prominentKirkwood gaps. It orbits the Sun in thecentral main-belt at a distance of 2.1–3.1 AU once every 4 years and 2 months (1,533 days). Its orbit has aneccentricity of 0.19 and aninclination of 13° with respect to theecliptic.[1] The firstprecovery ofZimmerwald was taken atPalomar Observatory in 1949, extending the body'sobservation arc by 20 years prior to its official discovery observation at Zimmerwald. During the 1950s, it was also identified atHeidelberg,Goethe Link andMcDonald Observatory.[10]
In May 2011, a rotationallightcurve ofZimmerwald was obtained by American astronomerRobert Stephens at the Center for Solar System Studies, California, using photometric observations taken at the Santana and Goat Mountain observatories (646,G79). Lightcurve analysis gave a very longrotation period of122±5 hours with a change in brightness of 0.60magnitude (U=2+). It is also suspected, that the body might be in a nonprincipal axis rotation, which is commonly known as "tumbling".[8] While theslowest rotators have periods above 1000 hours, the majority of minor planets have periodsshorter than 20 hours.
According to the surveys carried out by the JapaneseAkari satellite and NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Zimmerwald measures 10.17 and 10.70 kilometers in diameter, and its surface has analbedo between of 0.244 and 0.21, respectively (without preliminary results).[4][7] TheCollaborative Asteroid Lightcurve Link assumes an albedo of 0.21 – derived from15 Eunomia, the family's largest member and namesake – and calculates a diameter of 11.03 kilometers using anabsolute magnitude of 12.1.[3]
Thisminor planet was named for the small village ofZimmerwald, location of the discovering Zimmerwald Observatory. It is located about seven miles south of the Swiss capitalBern, after which the binary asteroid1313 Berna was named.[2] The officialnaming citation was published by theMinor Planet Center on 18 April 1977 (M.P.C. 4155).[11]
