159 Aemilia

159 Aemilia

Discovery
Discovered by	P. P. Henry
Discovery date	January 26, 1876
Designations
Named after	Via Aemilia
Alternative names	1959 EG1
Minor planet category	Main belt (Hygiea family)
Orbital characteristics
Epoch 26 November 2005 (JD 2453700.5)
Aphelion	515.348 Gm (3.445 AU)
Perihelion	412.241 Gm (2.756 AU)
Semi-major axis	463.794 Gm (3.100 AU)
Eccentricity	0.111
Orbital period	1993.879 d (5.46 a)
Average orbital speed	16.86 km/s
Mean anomaly	227.956°
Inclination	6.128°
Longitude of ascending node	134.336°
Argument of perihelion	335.594°
Physical characteristics
Dimensions	127.3 km
Mass	~1.4×1018 kg
Mean density	~1.4 g/cm³
Surface gravity	~0.024 m/s²
Escape velocity	~0.055 km/s
Rotation period	~1.05 d [1]
Albedo	0.0627 ± 0.0142
Temperature	~160 K max: 239K (-34° C)
Spectral type	C (Tholen)
Absolute magnitude (H)	8.10

159 Aemilia is a large main-belt asteroid. Aemilia was discovered by the French brothers Paul Henry and Prosper Henry on January 26, 1876. The credit for this discovery was given to Paul. It is probably named after the Via Aemilia, a Roman road in Italy that runs from Piacenza to Rimini.

This slowly rotating, dark asteroid has a primitive carbonaceous composition, based upon its classification as a C-type asteroid. Photometric observations made in 2006 gave a rotation period of about 25 hours. Subsequent observations made at the Oakley Observatory in Terre Haute, Indiana found a light curve period of 16.37 ± 0.02 hours, with variation in brightness of 0.24 ± 0.04 in magnitude.

It orbits within the Hygiea family, although it may be an unrelated interloping asteroid, as it is too big to have arisen from the cratering process that most probably produced that family. Two stellar occultations by Aemilia have been recorded so far, the first in 2001 and the second in 2003.^[2]