Leda (moon)
Outer moon of Jupiter
From Wikipedia, the free encyclopedia
Leda /ˈliːdə/, also known as Jupiter XIII, is one of the innermost and larger of irregular satellite of Jupiter.
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Discovery image of Leda taken by the Palomar Observatory in 1974 | |
| Discovery[1] | |
|---|---|
| Discovered by | Charles T. Kowal |
| Discovery site | Palomar Observatory |
| Discovery date | 14 September 1974 |
| Designations | |
Designation | Jupiter XIII |
| Pronunciation | /ˈliːdə/[2] |
Named after | Λήδα Lēdā |
| Adjectives | Ledian /ˈliːdiən/,[3] Ledean /ˈliːdiən/[4] or /liːˈdiːən/[5] |
| Orbital characteristics[6] | |
| Epoch 16 February 2017 (JD 2457800.5) | |
| Observation arc | 42.60 yr (15,561 days) |
| 0.0748405 AU (11,195,980 km) | |
| Eccentricity | 0.1648788 |
| +242.02 d | |
| 137.02571° | |
| 1° 29m 14.953s / day | |
| Inclination | 27.63631° (to ecliptic) |
| 190.18497° | |
| 312.92965° | |
| Satellite of | Jupiter |
| Group | Himalia group |
| Physical characteristics | |
| 21.5±1.7 km[7] | |
| Albedo | 0.034±0.006[7] |
Spectral type | C [7] |
| 20.2[8] | |
| 12.7[6] | |
Discovery and Naming
It was discovered by Charles T. Kowal at the Mount Palomar Observatory on September 14, 1974, after three nights' worth of photographic plates had been taken (September 11 through 13; Leda appears on all of them).[1][9]
It was named after Leda, who was raped[10] by Zeus, the Greek equivalent of Jupiter (who came to her in the form of a swan). Kowal suggested the name and the IAU endorsed it in 1975.[11]
Orbit
Leda orbits Jupiter at an average distance of 11,195,980 km in 242.02 days, at an inclination of about 28° to the ecliptic, in a prograde direction and with an eccentricity of 0.165.
Leda belongs to the Himalia group, a prograde group of moons orbiting between 11 and 13 million km from Jupiter at inclinations between 27 and 30°, and eccentricities between 0.11 and 0.24.
Physical characteristics
Leda has a diameter of about 21.5 kilometers, with a measured albedo of about 3,4%,[7] making it the smallest of Jupiter's classic irregular moons.
Like the other members of the Himalia group, the satellite appears gray (color indices B-V=0.66 ± 0,01, R-V=0.43 0,01),[12] which is typical for C-type asteroids.[7]
Origin
Leda probably did not form near Jupiter but was captured by Jupiter later. Like the other members of the Himaila group, which have similar orbits, Leda is probably the remnant of a broken, captured heliocentric asteroid.