Discovered by James Craig Watson Minor planet category Main belt Discovered 15 August 1868 Spectral type S-type asteroid Named after Helen of Troy | Discovery date 15 August 1868 Observation arc 145.07 yr (52986 d) Orbits Sun Discoverer James Craig Watson Discovery site Detroit Observatory | |
Aphelion 2.94606 AU (440.724 Gm) Perihelion 2.22353 AU (332.635 Gm) Similar 161 Athor, 114 Kassandra, 128 Nemesis, 107 Camilla, 132 Aethra | ||
101 Helena is a rocky main-belt asteroid. It was discovered by Canadian-American astronomer J. C. Watson on August 15, 1868, 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.
References
101 Helena Wikipedia(Text) CC BY-SA