390 Alma

390 Alma

A three-dimensional model of 390 Alma based on its light curve.
Discovery
Discovered by	Guillaume Bigourdan
Discovery date	March 24, 1894
Designations
Named after	Alma River
Alternative names	1894 BC; 1930 QW; 1950 BV; 1950 CH; 1953 YB; 1963 DF
Minor planet category	Main belt (Eunomia family)
Orbital characteristics
Epoch 30 January 2005 (JD 2453400.5)
Aphelion	448.268 Gm (2.996 AU)
Perihelion	345.512 Gm (2.31 AU)
Semi-major axis	396.89 Gm (2.653 AU)
Eccentricity	0.129
Orbital period	1578.364 d (4.32 a)
Average orbital speed	18.21 km/s
Mean anomaly	258.381°
Inclination	12.144°
Longitude of ascending node	305.342°
Argument of perihelion	190.074°
Physical characteristics
Dimensions	24 km[1]
Mass	~2×10^16 kg (estimate)
Mean density	~2.7 g/cm³ (estimate)[2]
Surface gravity	~0.009 m/s² (estimate)
Escape velocity	~0.015 km/s (estimate)
Rotation period	0.156 d[3]
Albedo	0.219
Temperature	~165 K max: 250 K (-23 °C)
Spectral type	S-type asteroid
Absolute magnitude (H)	10.39

390 Alma is a typical medium-sized Eunomian asteroid. It was Guillaume Bigourdan's only asteroid discovery. He discovered it on March 24, 1894 in Paris.

References

1. "Supplemental IRAS Minor Planet Survey".
2. G. A. Krasinsky; et al. (2002). "Hidden Mass in the Asteroid Belt". Icarus 158: 98.
3. "PDS lightcurve data".

• PDS Target Information

External links

• 390 Alma at the JPL Small-Body Database

• Discovery · Orbit diagram · Orbital elements · Physical parameters