234 Barbara

Main-belt asteroid

234 Barbara is a main belt asteroid that was discovered by German-American astronomer Christian Heinrich Friedrich Peters on August 12, 1883, in Clinton, New York. The object is orbiting the Sun with a semimajor axis of 2.385 AU, a period of 3.68 years, and an eccentricity of 0.25. The orbital plane is inclined by 15.37° to the plane of the ecliptic. It is classified as a stony S-type asteroid based upon its spectrum. The mean diameter of this object is estimated as 45.6 km.[2] It has a rotation rate of 26.5 hours, or a little over a day. It is possibly named for Saint Barbara, patron saint of mathematicians.[3][4]

Observations of light curves and stellar occultations suggest the surface exhibits large concave areas.[5] Polarimetric study of this asteroid reveals anomalous properties that suggests the regolith consists of a mixture of low and high albedo material. This may have been caused by fragmentation of an asteroid substrate with the spectral properties of CO3/CV3 carbonaceous chondrites.[6] It is the prototype for a class of asteroids called "Barbarians" that display a strong infrared absorption band at 2μm, which is a characteristic of an FeO–enriched spinel mineral. Multiple other examples of this class have since been discovered.[7]

Observations made in 2009 with ESO's Very Large Telescope Interferometer (VLTI) suggested that 234 Barbara may be a binary asteroid,[8] although a paper published in 2015 states that "the VLTI observations can be explained without the presence of a large satellite".[5]

References

  1. ^ a b Yeomans, Donald K., "234 Barbara", JPL Small-Body Database Browser, NASA Jet Propulsion Laboratory, retrieved 12 May 2016.
  2. ^ a b c Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science, 73 (1): 98–118, arXiv:1203.4336, Bibcode:2012P&SS...73...98C, doi:10.1016/j.pss.2012.03.009, S2CID 119226456. See Table 1.
  3. ^ Schmadel, Lutz (5 August 2003). Dictionary of Minor Planet Names. Springer Science & Business Media. ISBN 9783540002383 – via Google Books.
  4. ^ Paluzíe-Borrell, Antonio (11 July 1963). "The Names of the Minor Planets and Their Meanings". J. Meeus, Kesselberg Sterrenwacht – via Google Books.
  5. ^ a b Tanga, P.; et al. (April 2015), "The non-convex shape of (234) Barbara, the first Barbarian*", Monthly Notices of the Royal Astronomical Society, 448 (4): 3382–3390, arXiv:1502.00460, Bibcode:2015MNRAS.448.3382T, doi:10.1093/mnras/stv229.
  6. ^ Gil-Hutton, R.; et al. (April 2008), "New cases of unusual polarimetric behavior in asteroids", Astronomy and Astrophysics, 482 (1): 309–314, Bibcode:2008A&A...482..309G, doi:10.1051/0004-6361:20078965.
  7. ^ Devogèle, M.; et al. (April 2018), "New polarimetric and spectroscopic evidence of anomalous enrichment in spinel-bearing calcium-aluminium-rich inclusions among L-type asteroids", Icarus, 304: 31–57, arXiv:1802.06975, Bibcode:2018Icar..304...31D, doi:10.1016/j.icarus.2017.12.026, S2CID 54992862
  8. ^ "Powerful New Technique to Measure Asteroids' Sizes and Shapes". European Southern Observatory. Archived from the original on 22 December 2015. Retrieved 19 December 2015.
  • The Asteroid Orbital Elements Database
  • Minor Planet Discovery Circumstances
  • Asteroid Lightcurve Data File
  • 234 Barbara at AstDyS-2, Asteroids—Dynamic Site
    • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
  • 234 Barbara at the JPL Small-Body Database Edit this at Wikidata
    • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters
Authority control databases Edit this at Wikidata
  • JPL SBDB
  • MPC