159 Aemilia

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159 Aemilia
Discovered by P. P. Henry
Discovery date January 26, 1876
Named after
Via Aemilia
1904 OK, 1959 EG1
Main belt (Hygiea family)
Orbital characteristics[1]
Epoch 26 November 2005 (JD 2453700.5)
Aphelion 515.348 Gm (3.445 AU)
Perihelion 412.241 Gm (2.756 AU)
463.794 Gm (3.100 AU)
Eccentricity 0.111
1993.879 d (5.46 a)
16.86 km/s
Inclination 6.128°
Physical characteristics
Dimensions 127.3[2] km
Mass ~1.4×1018 kg
Mean density
~1.4 g/cm³[3]
~0.024 m/s²
~0.055 km/s
~1.05 d [1]
Albedo 0.0627 ± 0.0142[2]
Temperature ~160 K
max: 239K (-34° C)
Spectral type
C[2] (Tholen)

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.[2] 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.[4]

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]


  1. ^ Yeomans, Donald K., "159 Aemilia", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), retrieved 2013-03-30. 
  2. ^ a b c d e Pravec, P. et al. (May 2012), "Absolute Magnitudes of Asteroids and a Revision of Asteroid Albedo Estimates from WISE Thermal Observations", Asteroids, Comets, Meteors 2012, Proceedings of the conference held May 16-20, 2012 in Niigata, Japan (1667), Bibcode:2012LPICo1667.6089P.  See Table 4.
  3. ^ Krasinsky, G. A. et al. (July 2002), "Hidden Mass in the Asteroid Belt", Icarus 158 (1): 98–105, Bibcode:2002Icar..158...98K, doi:10.1006/icar.2002.6837. 
  4. ^ Ditteon, Richard; Hawkins, Scot (September 2007), "Asteroid Lightcurve Analysis at the Oakley Observatory - October-November 2006", Bulletin of the Minor Planets Section of the Association of Lunar and Planetary Observers 34 (3): 59–64, Bibcode:2007MPBu...34...59D.