1302 Werra
Themistian asteroid
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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]
| Discovery[1] | |
|---|---|
| Discovered by | K. Reinmuth |
| Discovery site | Heidelberg Obs. |
| Discovery date | 28 September 1924 |
| Designations | |
| (1302) Werra | |
Named after | Werra[2] (river in central Germany) |
| 1924 SV · 1930 WD | |
| main-belt · (outer) Themis[3][4] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 93.10 yr (34,003 days) |
| Aphelion | 3.6580 AU |
| Perihelion | 2.5677 AU |
| 3.1128 AU | |
| Eccentricity | 0.1751 |
| 5.49 yr (2,006 days) | |
| 251.95° | |
| 0° 10m 46.2s / day | |
| Inclination | 2.5958° |
| 90.142° | |
| 354.64° | |
| Physical characteristics | |
| Dimensions | 24.35±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] | |
| 0.0710±0.0158[7] 0.076±0.006[8] 0.08 (assumed)[3] 0.10±0.07[5] 0.102±0.004[6] | |
| C (assumed)[3] | |
| 10.60[6] · 10.8[7] · 10.90[1][3][5] · 10.99±0.27[10] | |
Orbit and classification
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 2.6â3.7 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
Werra is an assumed carbonaceous C-type asteroid,[3] which is the overall spectral type for members of the Themis family.[12]:â23â
Rotation period
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
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]
Naming
This minor planet was named after the river Werra in central Germany. It merges 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]
