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 byPaul Henry and Prosper Henry
Discovery date11 September 1872
MPC designation(125) Liberatrix
Main belt
Orbital characteristics[1]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc143.54 yr (52428 d)
Aphelion2.95698 AU (442.358 Gm)
Perihelion2.53084 AU (378.608 Gm)
2.74391 AU (410.483 Gm)
4.55 yr (1660.2 d)
17.96 km/s
0° 13m 0.642s / day
Earth MOID1.51912 AU (227.257 Gm)
Jupiter MOID2.13019 AU (318.672 Gm)
Physical characteristics
Dimensions43.58±2.3 km[1]
61.058 km[2]
Mass8.7×1016 kg
Mean density
2.0 g/cm³
Equatorial surface gravity
0.0122 m/s²
Equatorial escape velocity
0.0231 km/s
3.968 h (0.1653 d)[1][3]
0.1305 ± 0.0269[2]
Temperature~168 K
M (Tholen)[2]
9.04,[1] 8.90[2]

Liberatrix (minor planet designation: 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. Early on December 11, 2014, Liberatrix will occult a 9th magnitude star and will be visible over the majority of Southern California and a swath of Mexico.


  1. ^ a b c d e Yeomans, Donald K., "125 Liberatrix", JPL Small-Body Database Browser, NASA Jet Propulsion Laboratory, retrieved 12 May 2016.
  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), pp. 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), pp. 141–158, Bibcode:2005Icar..175..141H, doi:10.1016/j.icarus.2004.10.017.

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