159 Aemilia

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.

DiscoveredbyP. P. Henry

Discoverydate26 January 1876

MPCdesignation

(159) Aemilia

Pronunciation/ɪˈmɪliə/^[1]

Quick facts Discovery, Discovered by ...

159 Aemilia

3D convex shape model of 159 Aemilia
Discovery
Discovered by	P. P. Henry
Discovery date	26 January 1876
Designations
MPC designation	(159) Aemilia
Pronunciation	/ɪˈmɪliə/[1]
Named after	Via Aemilia
Alternative designations	A876 BA; 1959 EG1
Minor planet category	Main belt (Hygiea family)
Adjectives	Aemilian /ɪˈmɪliən/[2]
Orbital characteristics[3]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc	112.24 yr (40996 d)
Aphelion	3.4377 AU (514.27 Gm)
Perihelion	2.76896 AU (414.231 Gm)
Semi-major axis	3.1033 AU (464.25 Gm)
Eccentricity	0.10775
Orbital period (sidereal)	5.47 yr (1996.8 d)
Average orbital speed	16.86 km/s
Mean anomaly	214.036°
Mean motion	0° 10m 49.008s / day
Inclination	6.1308°
Longitude of ascending node	134.132°
Argument of perihelion	333.387°
Earth MOID	1.78581 AU (267.153 Gm)
Jupiter MOID	1.67782 AU (250.998 Gm)
TJupiter	3.203
Physical characteristics
Dimensions	124.97±2.4 km[3] 127.3 km[4]
Mass	~1.4×1018 kg
Mean density	~1.4 g/cm3[5]
Equatorial surface gravity	~0.024 m/s2
Equatorial escape velocity	~0.055 km/s
Synodic rotation period	24.476 h (1.0198 d)[3] ~1.05 d[6]
Geometric albedo	0.0639±0.003[3] 0.0627 ± 0.0142[4]
Temperature	~160 K max: 239 K (−34 Â°C; −29 Â°F)
Spectral type	C[4] (Tholen)
Absolute magnitude (H)	8.12,[3] 8.10[4]

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This slowly rotating, dark asteroid has a primitive carbonaceous composition, based upon its classification as a C-type asteroid.^[4] 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.^[7]

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. Three stellar occultations by Aemilia have been recorded so far, the first in 2001, the second in 2003 and the third in 2016 ^[8]