125 Liberatrix

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125 Liberatrix
125Liberatrix (Lightcurve Inversion).png
A three-dimensional model of 125 Liberatrix based on its light curve.
Discovered by Paul Henry and Prosper Henry
Discovery date September 11, 1872
Alternative names  
Minor planet category Main belt
Orbital characteristics[1]
Epoch December 31, 2006 (JD 2454100.5)
Aphelion 443.561 Gm (2.965 AU)
Perihelion 376.865 Gm (2.519 AU)
Semi-major axis 410.213 Gm (2.742 AU)
Eccentricity 0.081
Orbital period 1658.534 d (4.54 a)
Average orbital speed 17.96 km/s
Mean anomaly 267.835°
Inclination 4.656°
Longitude of ascending node 169.160°
Argument of perihelion 110.210°
Physical characteristics
Dimensions 61.058[2] km
Mass 8.7×1016 kg
Mean density 2.0 g/cm³
Equatorial surface gravity 0.0122 m/s²
Escape velocity 0.0231 km/s
Rotation period 3.968[3] h
Albedo 0.1305 ± 0.0269[2]
Temperature ~168 K
Spectral type M (Tholen)[2]
Absolute magnitude (H) 8.90[2]

125 Liberatrix is a main-belt asteroid. It has a relatively reflective surface and an M-type spectrum. Liberatrix is a member of an asteroid family bearing its own name.

Discovery and name[edit]

It was discovered by Prosper Henry on September 11, 1872 from Paris. Some sources give Paul Henry sole credit for its discovery.[4] The asteroid's name is a feminine version of the word "liberator". Henry may have chosen the name to mark the liberation of France from Prussia during the Franco-Prussian War in 1870. More specifically, it may honor Adolphe Thiers, the first President of the French Republic, who arranged a loan that enabled the Prussian troops to be removed from France.[4]


In the late 1990s, a network of astronomers worldwide gathered lightcurve data to derive the spin states and shape models of 10 asteroids, including Liberatrix. Liberatrix's lightcurve has a large amplitude of 0.4 in magnitude, indicating an elongated or irregular shape.[3][5]

The spectrum of this asteroid matches a M-type asteroid. It may be the remnant of an asteroid that had undergone differentiation, with orthopyroxene minerals scattered evenly across the surface. There is no indication of hydration.[6]

To date, there have been at least two observed occultations by Liberatrix.


  1. ^ Yeomans, Donald K., "125 Liberatrix", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), retrieved 2013-03-25. 
  2. ^ a b c d 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. 
  3. ^ a b Durech, J. et al. (April 2007), "Physical models of ten asteroids from an observers' collaboration network", Astronomy and Astrophysics 465 (1): 331–337, Bibcode:2007A&A...465..331D, doi:10.1051/0004-6361:20066347. 
  4. ^ a b Schmadel Lutz D. Dictionary of Minor Planet Names (fifth edition), Springer, 2003. ISBN 3-540-00238-3.
  5. ^ Durech, J.; Kaasalainen, M.; Marciniak, A.; Allen, W. H. et al. "Asteroid brightness and geometry," Astronomy and Astrophysics, Volume 465, Issue 1, April I 2007, pp. 331-337.
  6. ^ Hardersen, Paul S.; Gaffey, Michael J.; Abell, Paul A. (January 1983), "Near-IR spectral evidence for the presence of iron-poor orthopyroxenes on the surfaces of six M-type asteroids", Icarus 175 (1): 141-158, Bibcode:2005Icar..175..141H, doi:10.1016/j.icarus.2004.10.017, retrieved 2013-03-30.