(31) Euphrosyne

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(31) Euphrosyne
Properties of the orbit ( animation )
Orbit type Main belt asteroid
Asteroid family Euphrosyne family
Major semi-axis 3.152  AU
eccentricity 0.224
Perihelion - aphelion 2.445 AU - 3.859 AU
Inclination of the orbit plane 26.3 °
Length of the ascending node 31.2 °
Argument of the periapsis 61.8 °
Time of passage of the perihelion May 10, 2012
Sidereal period of rotation 5 a 223 d
Mean orbital velocity 16.6 km / s
Physical Properties
Medium diameter 267 km
Albedo 0.05
Rotation period 5.5 h
Absolute brightness 6.7 likes
Spectral class
(according to Tholen)
Spectral class
(according to SMASSII)
Explorer James Ferguson
Date of discovery September 1, 1854
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.

(31) Euphrosyne is an asteroid of the main outer asteroid belt discovered by James Ferguson on September 1, 1854 , from the Naval Observatory in Washington, DC .

The celestial body was named after Euphrosyne , one of the three Charites (graces) of Greek mythology .

With a diameter of 256 km, Euphrosyne is one of the largest asteroids in the main belt. The asteroid has a dark carbonaceous surface with an albedo of 0.05. It rotates around its own axis in around 5.5 hours.

Euphrosyne is the namesake of a complex family of roughly two thousand asteroids that share similar spectral properties and orbital elements. It is believed that they were formed by a collision about 280 million years ago. All members have relatively high inclines.

In 2019, a small satellite (S / 2019 (31) 1 alias Euphrosyne I) was discovered, which is believed to have been created by the same collision event as the family. Preliminary orbital calculations showed an orbital period of about 1.2 days and a semi-major axis of 670 km. VLT images suggest the moon is 4 km in diameter, assuming it has the same albedo as Euphrosyne.

See also

Web links

Individual evidence

  1. a b Bin Yang at al. : Binary asteroid (31) Euphrosyne: Ice-rich and nearly spherical , on: arXix from July 16, 2020, PDF
  2. Bojan Novaković et al. : Families among high-inclination asteroids , in: Icarus 216 (1), November 2011, pp. 69–81, Bibcode: 2011Icar..216 ... 69N , doi: 10.1016 / j.icarus.2011.08.016