101 Helena
From Infogalactic: the planetary knowledge core
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Discovery | |
---|---|
Discovered by | James Craig Watson |
Discovery date | August 15, 1868 |
Designations | |
Named after
|
Helen of Troy |
Main belt | |
Orbital characteristics[1] | |
Epoch December 31, 2006 (JD 2454100.5) | |
Aphelion | 441.092 Gm (2.949 AU) |
Perihelion | 331.683 Gm (2.217 AU) |
386.387 Gm (2.583 AU) | |
Eccentricity | 0.1410 |
1516.67 d (4.15 a) | |
Average orbital speed
|
18.44 km/s |
125.599° | |
Inclination | 10.1996° |
343.44° | |
347.34° | |
Physical characteristics | |
Dimensions | 65.8[1] km |
Mass | 3.0×1017 kg |
Mean density
|
2.0 g/cm³ |
0.0184 m/s² | |
0.0348 km/s | |
23.080[1] h | |
Albedo | 0.1898[1] |
Temperature | ~173 K |
Spectral type
|
S[2] |
8.33 | |
101 Helena is a rocky main-belt asteroid. It was discovered by Canadian-American astronomer J. C. Watson on August 15, 1868,[3] and was named after Helen of Troy in Greek mythology. Radar observations were made of this object on Oct 7 and 19, 2001 from the Arecibo Observatory. Analysis of the data gave an estimated ellipsoidal diameter of 71×63×63 ± 16% km. The diameter estimated from IRAS infrared measurements is 66 km. It is classified as an S-type asteroid in the Tholen system.[2][4]
References
- ↑ 1.0 1.1 1.2 1.3 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 2.0 2.1 Lua error in package.lua at line 80: module 'strict' not found. See appendix A.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
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