1775 Zimmerwald

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1775 Zimmerwald
Discovery [1]
Discovered by P. Wild
Discovery site Zimmerwald Obs.
Discovery date 13 May 1969
MPC designation (1775) Zimmerwald
Named after
(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 3.0866 AU
Perihelion 2.1182 AU
2.6024 AU
Eccentricity 0.1861
4.20 yr (1,533 days)
0° 14m 5.28s / day
Inclination 12.555°
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±5 h[8]
0.21 (assumed)[3]
12.08±0.31[9] · 12.1[1][3][4][5] · 12.26[7]

1775 Zimmerwald, provisional designation 1969 JA, is a stony Eunomian asteroid and slow rotator from the middle region of the asteroid belt, approximately 10 kilometers in diameter. It was discovered on 13 May 1969, by Swiss astronomer Paul Wild at Zimmerwald Observatory near Bern, Switzerland.[10] It is named for the village of Zimmerwald, where the discovering observatory is located.[2]

Orbit and classification[edit]

Zimmerwald is a member of the Eunomia family, a large group of mostly stony S-type asteroids and the most prominent family in the intermediate main-belt, which is located between two prominent Kirkwood gaps. It orbits the Sun in the central main-belt at a distance of 2.1–3.1 AU once every 4 years and 2 months (1,533 days). Its orbit has an eccentricity of 0.19 and an inclination of 13° with respect to the ecliptic.[1] The first precovery of Zimmerwald was taken at Palomar Observatory in 1949, extending the body's observation arc by 20 years prior to its official discovery observation at Zimmerwald. During the 1950s, it was also identified at Heidelberg, Goethe Link and McDonald Observatory.[10]

Physical characteristics[edit]

Rotation period[edit]

In May 2011, a rotational lightcurve of Zimmerwald was obtained by American astronomer Robert 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 long rotation period of 122±5 hours with a change in brightness of 0.60 magnitude (U=2+). It is also suspected, that the body might be in a nonprincipal axis rotation, which is commonly known as "tumbling".[8] While the slowest rotators have periods above 1000 hours, the majority of minor planets have periods shorter than 20 hours.

Diameter and albedo[edit]

According to the surveys carried out by the Japanese Akari satellite and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Zimmerwald measures 10.17 and 10.70 kilometers in diameter, and its surface has an albedo between of 0.244 and 0.21, respectively (without preliminary results).[4][7] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.21 – derived from 15 Eunomia, the family's largest member and namesake – and calculates a diameter of 11.03 kilometers using an absolute magnitude of 12.1.[3]


This minor planet was named for the small village of Zimmerwald, location of the discovering Zimmerwald Observatory. It is located about seven miles south of the Swiss capital Bern, after which the binary asteroid 1313 Berna was named.[2] The official naming citation was published by the Minor Planet Center before November 1977 (M.P.C. 4155).[11]


  1. ^ a b c d "JPL Small-Body Database Browser: 1775 Zimmerwald (1969 JA)" (2017-02-04 last obs.). Jet Propulsion Laboratory. Retrieved 8 June 2017. 
  2. ^ a b c Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1775) Zimmerwald. Springer Berlin Heidelberg. p. 142. ISBN 978-3-540-00238-3. Retrieved 26 January 2017. 
  3. ^ a b c d e f "LCDB Data for (1775) Zimmerwald". Asteroid Lightcurve Database (LCDB). Retrieved 26 January 2017. 
  4. ^ a b c d Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. Retrieved 26 January 2017. 
  5. ^ a b c Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results" (PDF). The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407Freely accessible. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 26 January 2017. 
  6. ^ a b Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J.; et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal. 741 (2): 20. arXiv:1109.4096Freely accessible. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. Retrieved 26 January 2017. 
  7. ^ a b c d Nugent, C. R.; Mainzer, A.; Bauer, J.; Cutri, R. M.; Kramer, E. A.; Grav, T.; et al. (September 2016). "NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos". The Astronomical Journal. 152 (3): 12. arXiv:1606.08923Freely accessible. Bibcode:2016AJ....152...63N. doi:10.3847/0004-6256/152/3/63. Retrieved 26 January 2017. 
  8. ^ a b Stephens, Robert D. (October 2011). "Asteroids Observed from GMARS and Sanana Observatories: 2011 April - June". The Minor Planet Bulletin. 38 (4): 211–212. Bibcode:2011MPBu...38..211S. ISSN 1052-8091. Retrieved 26 January 2017. 
  9. ^ Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762Freely accessible. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 26 January 2017. 
  10. ^ a b "1775 Zimmerwald (1969 JA)". Minor Planet Center. Retrieved 26 January 2017. 
  11. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 26 January 2017. 

External links[edit]