木卫十三1974

概述

木卫十三是一颗逆行的不规则卫星，在1974年9月11日被查尔斯·科瓦尔发现，由希腊神话中的勒达（宙斯的情人）命名。

木卫十三跟另外四颗的卫星是希玛利亚群的一员，它们离木星距离从1100万公里道1300万公里不等，与黄道交角在27.5°左右。木卫十三因为受到太阳的摄动，因此的轨道非常的不稳定。

Leda, also known as Jupiter XIII, is one of the innermost irregular satellites of Jupiter.

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).

It was named after Leda, who was raped 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.

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%.

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), which is typical for C-type asteroids.

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.