125 Liberatrix

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.

125 Liberatrix

A three-dimensional model of 125 Liberatrix based on its light curve.
Discovery
Discovered by	Paul Henry and Prosper Henry
Discovery date	11 September 1872
Designations
MPC designation	(125) Liberatrix
Pronunciation	/ˈlɪbəreɪtrɪks/[1]
Alternative designations	A872 RA; 1902 EG; 1943 FE; 1949 OE1; 1949 SM; 1954 TD1
Minor planet category	Main belt (liberatrix)
Orbital characteristics[2]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc	143.54 yr (52428 d)
Aphelion	2.95698 AU (442.358 Gm)
Perihelion	2.53084 AU (378.608 Gm)
Semi-major axis	2.74391 AU (410.483 Gm)
Eccentricity	0.077651
Orbital period (sidereal)	4.55 yr (1660.2 d)
Average orbital speed	17.96 km/s
Mean anomaly	307.971°
Mean motion	0° 13m 0.642s / day
Inclination	4.66407°
Longitude of ascending node	169.003°
Argument of perihelion	109.288°
Earth MOID	1.51912 AU (227.257 Gm)
Jupiter MOID	2.13019 AU (318.672 Gm)
TJupiter	3.340
Physical characteristics
Dimensions	43.58±2.3 km[2] 61.058 km[3]
Mass	8.7×1016 kg
Mean density	2.0 g/cm3
Equatorial surface gravity	0.0122 m/s2
Equatorial escape velocity	0.0231 km/s
Synodic rotation period	3.968 h (0.1653 d)[2][4]
Geometric albedo	0.2253±0.026[2] 0.1305 ± 0.0269[3]
Temperature	~168 K
Spectral type	M (Tholen)[3]
Absolute magnitude (H)	9.04,[2] 8.90[3]

It was discovered by Prosper Henry on 11 September 1872, from Paris. Some sources give Paul Henry sole credit for its discovery.^[5] 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.^[5]

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.^[4][6]

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.^[7]

To date, there have been at least two observed occultations by Liberatrix. Early on 11 December 2014, Liberatrix occulted a 9th magnitude star and will be visible over the majority of Southern California and a swath of Mexico.^{[citation needed]}

References

1. "liberatrix". Lexico UK English Dictionary. Oxford University Press. Archived from the original on 22 March 2020.
2. Yeomans, Donald K., "125 Liberatrix", JPL Small-Body Database Browser, NASA Jet Propulsion Laboratory, retrieved 12 May 2016.
3. 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, no. 1667, Bibcode:2012LPICo1667.6089P.
4. Durech, J.; et al. (April 2007), "Physical models of ten asteroids from an observers' collaboration network", Astronomy and Astrophysics, vol. 465, no. 1, pp. 331–337, Bibcode:2007A&A...465..331D, doi:10.1051/0004-6361:20066347.
5. Schmadel Lutz D. Dictionary of Minor Planet Names (fifth edition), Springer, 2003. ISBN 3-540-00238-3.
6. 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.
7. 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, vol. 175, no. 1, pp. 141–158, Bibcode:2005Icar..175..141H, doi:10.1016/j.icarus.2004.10.017.

External links

• 125 Liberatrix at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 125 Liberatrix at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters