1302 Werra

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1302 Werra
Discovery [1]
Discovered byK. Reinmuth
Discovery siteHeidelberg Obs.
Discovery date28 September 1924
MPC designation(1302) Werra
Named after
(river in central Germany)
1924 SV · 1930 WD
main-belt · (outer)
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc93.10 yr (34,003 days)
Aphelion3.6580 AU
Perihelion2.5677 AU
3.1128 AU
5.49 yr (2,006 days)
0° 10m 46.2s / day
Physical characteristics
Dimensions24.35±6.54 km[5]
31.04 km (calculated)[3]
32.18±0.50 km[6]
34.542±0.258 km[7]
35.041±0.114 km[8]
48 h (retracted)[9]
0.08 (assumed)[3]
C (assumed)[3]
10.60[6] · 10.8[7] · 10.90[1][3][5] · 10.99±0.27[10]

1302 Werra, provisional designation 1924 SV, is a Themistian asteroid from the outer regions of the asteroid belt, approximately 30 kilometers in diameter. It was discovered on 28 September 1924, by German astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory.[11] The asteroid was named for the river Werra in central Germany.[2]

Orbit and classification[edit]

Werra is a Themistian asteroid that belongs to the Themis family (602),[3][4] a very large family of carbonaceous asteroids, named after its parent body 24 Themis.[12]

It orbits the Sun in the outer main-belt at a distance of 2.6–3.7 AU once every 5 years and 6 months (2,006 days; semi-major axis of 3.11 AU). Its orbit has an eccentricity of 0.18 and an inclination of 3° with respect to the ecliptic.[1] The body's observation arc begins at Heidelberg with its official discovery observation in September 1924.[11]

Physical characteristics[edit]

Werra is an assumed carbonaceous C-type asteroid,[3] which is the overall spectral type for members of the Themis family.[12]:23

Rotation period[edit]

In March 2009, a fragmentary lightcurve of Werra was obtained from photometric observations by French amateur astronomer Pierre Antonini. Lightcurve analysis gave a poorly constraint rotation period of 2 days with a brightness amplitude of less than 0.1 magnitude.[9] The result was later retracted at the Lightcurve Data Base (U=n.a.). As of 2017, no secure period has been obtained.[3]

Diameter and albedo[edit]

According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Werra measures between 24.35 and 35.041 kilometers in diameter and its surface has an albedo between 0.0710 and 0.102.[5][6][7][8]

The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.08 and calculates a diameter of 31.04 kilometers based on an absolute magnitude of 10.9.[3]


This minor planet was named after the river Werra in central Germany. It confluences with the Fulda in Hannoversch-Münden, Lower Saxony, to form the river Weser. The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 119).[2]


  1. ^ a b c d "JPL Small-Body Database Browser: 1302 Werra (1924 SV)" (2017-11-02 last obs.). Jet Propulsion Laboratory. Retrieved 11 December 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(1302) Werra". Dictionary of Minor Planet Names – (1302) Werra. Springer Berlin Heidelberg. p. 107. doi:10.1007/978-3-540-29925-7_1303. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f g h i "LCDB Data for (1302) Werra". Asteroid Lightcurve Database (LCDB). Retrieved 11 December 2017.
  4. ^ a b "Small Bodies Data Ferret". Nesvorny HCM Asteroid Families V3.0. Retrieved 11 December 2017.
  5. ^ a b c d Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117. Retrieved 11 December 2017.
  6. ^ 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 11 December 2017.
  7. ^ a b c d Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90.
  8. ^ a b c Masiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R.; et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal. 791 (2): 11. arXiv:1406.6645. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121.
  9. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1302) Werra". Geneva Observatory. Retrieved 11 December 2017.
  10. ^ 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:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 11 December 2017.
  11. ^ a b "1302 Werra (1924 SV)". Minor Planet Center. Retrieved 11 December 2017.
  12. ^ a b Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). Identification and Dynamical Properties of Asteroid Families. Asteroids IV. pp. 297–321. arXiv:1502.01628. Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN 9780816532131.

External links[edit]