हेलेन (चंद्रमा)

हेलेन (Helene) (/ˈhɛlɨniː/ HEL-ə-nee; यूनानी : Ἑλένη), शनि का एक प्राकृतिक उपग्रह है । It was discovered by Pierre Laques and Jean Lecacheux in 1980 from ground-based observations at Pic du Midi Observatory, and was designated S/1980 S 6. In 1988 it was officially named after Helen of Troy, who was the granddaughter of Cronus (Saturn) in Greek mythology. The moon is also designated Saturn XII (12), a number which it received in 1982, under the designation Dione B, because it is co-orbital with Dione and located in its leading Lagrangian point (साँचा:L4). It is one of four known trojan moons.

हेलेन

Cassini image of Helene against the backdrop of Saturn's clouds (March 3, 2010)
खोज
खोज कर्ता	Laques and Lecacheux
खोज का स्थान	Pic du Midi Observatory
खोज की तिथि	1 मार्च, 1980
उपनाम
प्रावधानिक नाम	हेलेन डायोनी B सेटर्न XII (12) S/1980 S 6
कक्षीय विशेषताएँ
अर्ध मुख्य अक्ष	377,396 किमी
विकेन्द्रता	0.0022
परिक्रमण काल	2.736915 दिवस
झुकाव	0.199° (शनि के विषुव वृत्त से)
स्वामी ग्रह	शनि डायोनी (L4 ट्रोजन)
भौतिक विशेषताएँ
परिमाण	43.4×38.2×26 किमी
माध्य त्रिज्या	17.6 ± 0.4 किमी
अल्बेडो	1.67 ± 0.20 (ज्यामितिय)