(617) Patroclus
Asteroid (617) Patroclus |
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Properties of the orbit ( animation ) | |
Orbit type | Jupiter Trojan (L 5 ) |
Major semi-axis | 5.217 AU |
eccentricity | 0.1383 |
Perihelion - aphelion | 4.496 AU - 5.939 AU |
Inclination of the orbit plane | 22.05 ° |
Length of the ascending node | 44.355 ° |
Argument of the periapsis | 308.373 ° |
Time of passage of the perihelion | July 31, 2012 |
Sidereal period | 11 a 339 d |
Mean orbital velocity | 13.0 km / s |
Physical Properties | |
Medium diameter | 122 ± 3 km |
Dimensions | 1.36 ± 0.11 x 10 18 | kg
Albedo | 0.0471 |
Medium density | 0.8 ± 0.2 g / cm³ |
Rotation period | 102 h 48 min |
Absolute brightness | 8.19 likes |
Spectral class | P |
history | |
Explorer | August Kopff |
Date of discovery | October 17, 1906 |
Another name | 1906 VY, 1941 XC, 1962 NB |
Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . The affiliation to an asteroid family is automatically determined from the AstDyS-2 database . Please also note the note on asteroid items. |
(617) Patroclus is an asteroid belonging to the group of Trojans . It is used to describe asteroids that move on the orbit of Jupiter around the sun.
Patroclus was discovered in 1906 as the second Trojan horse. It was named after the warrior Patroclus from Greek mythology.
Patroclus is located near Jupiter's Lagrange point L5. Its orbit runs between 4,496 ( perihelion ) and 5,939 ( aphelion ) astronomical units and is strongly inclined towards the ecliptic at 22.0 ° . The orbital eccentricity is 0.138.
During the opposition , Patroclus achieved a brightness of 16.2 mag . It is therefore an extremely faint object in the night sky.
Patroclus' diameter was previously estimated to be around 150 km. Investigations with the Keck II telescope on Mauna Kea in Hawaii uncovered the dual nature of the asteroid. In addition to Patroclus, with a diameter of 122 km, there is a second component with the designation S / 2001 (617) 1 and the name Menoetius , whose diameter is estimated at 113 kilometers. Patroclus is therefore a double asteroid , the components of which move around the common center of gravity at a distance of about 680 km from each other .
On January 4, 2017, NASA decided to deploy the Lucy space probe , which is scheduled to start in October 2021 and initially the L 4 Trojans (3548) Eurybates , (15094) Polymele , (11351) Leucus and (21900 ) between 2027 and 2028 ) Orus should investigate. Then the probe will swing-by the earth to reach Patroclus and Menoetius in March 2033 and explore them up close.
See also
Web links
- Patroclus is actually a comet (astronews.com)
- International Astronomical Union Circular No. 7741 October 29, 2001 (Discovery of Menoetius)
- Wm. Robert Johnston: (617) Patroclus and Menoetius (English)