18 Melpomene

From Wikipedia, the free encyclopedia

**18 Melpomene**
Discovery
Discovered by	John Russell Hind
Discovery date	June 24, 1852
Designations
Alternative names	none
Minor planet category	Main belt
Orbital characteristics
Epoch October 22, 2004 (JD 2453300.5)
Aphelion	418.414 Gm (2.797 AU)
Perihelion	268.472 Gm (1.795 AU)
Semi-major axis	343.443 G m (2.296 AU)
Eccentricity	0.218
Orbital period	1270.552 d (3.48 a)
Average orbital speed	19.42 km/s
Mean anomaly	205.245°
Inclination	10.126°
Longitude of ascending node	150.547°
Argument of perihelion	227.975°
Physical characteristics
Dimensions	140.6 km (150×125)^[1]
Mass	~2.9×10¹⁸ kg
Mean density	2.0? g/cm³
Equatorial surface gravity	~0.0393 m/s²
Escape velocity	~0.0743 km/s
Rotation period	0.482 21 d (11.573 h) ^[2]
Albedo	0.223 (geometric) ^[3]
Temperature	~177 K
Spectral type	S
Apparent magnitude	7.5^[4] to 12.0
Absolute magnitude	6.51
Angular diameter	0.23" to 0.059"

18 Melpomene (pronounced /mɛlˈpɒmɪni/, Greek: Μελπομένη) is a large, bright Main belt asteroid. It is composed of silicates and metals.

It was discovered by J. R. Hind on June 24, 1852 and named after Melpomene, the Muse of tragedy in Greek mythology.

Melpomene occulted the star SAO 114159 on December 11, 1978. A possible Melpomenean satellite with a diameter at least 37 km was detected. The satellite candidate received a provisional designation S/1978 (18) 1 [3].

Melpomene was observed with the Hubble Space Telescope in 1993. It was able to resolve the asteroid's slightly elongated shape, but no satellites were detected [4].

[edit] References

^ http://web.media.mit.edu/~win/hstpub.pdf
^ [1]^{[dead link]}
^ [2]^{[dead link]}
^ Donald H. Menzel and Jay M. Pasachoff (1983). A Field Guide to the Stars and Planets, 2nd edition, Boston, MA: Houghton Mifflin, p. 391. ISBN 0395348358.

[edit] External links

Orbital simulation from JPL (Java) / Ephemeris

v • d • e Minor planets navigator

17 Thetis · 18 Melpomene · 19 Fortuna

v • d • e Small Solar System bodies

Asteroids (Vulcanoids · Near-Earth · Main belt · Jupiter Trojans · Centaurs · Damocloids · Neptune Trojans · Groups · Families · Moons) Comets · Trans-Neptunians (Kuiper belt · Scattered disc objects · Oort cloud) · Minor planets · Meteoroids

Lists: Minor planets · Asteroid groups and families · Binary asteroids · Asteroid moons See also: Near-Earth object · Dwarf planet · Planet · Solar System · Pronunciation of asteroid names · Meanings of asteroid names.