110 Lydia

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110 Lydia
110Lydia (Lightcurve Inversion).png
A three-dimensional model of 110 Lydia based on its light curve.
Discovery
Discovered by Alphonse Borrelly
Discovery date April 19, 1870
Designations
Named after
Lydia
Minor planet category Main belt, lydia family
Orbital characteristics[1]
Epoch December 31, 2006 (JD 2454100.5)
Aphelion 440.756 Gm (2.946 AU)
Perihelion 377.016 Gm (2.520 AU)
408.886 Gm (2.733 AU)
Eccentricity 0.078
1650.493 d (4.52 a)
17.99 km/s
306.394°
Inclination 5.974°
56.993°
281.953°
Physical characteristics
Dimensions 86.090[2] km
Mass 6.7×1017 kg
0.0241 m/s²
0.0455 km/s
10.9258[3] hours
Albedo 0.181[2]
Temperature ~168 K
Spectral type
M (Tholen)
X (Bus)
Xk (DeMeo et al)[4]
7.80[2]

110 Lydia is a large main-belt asteroid with an M-type spectrum,[4] and thus may be metallic in composition, consisting primarily of nickel-iron. It was discovered by French astronomer Alphonse Borrelly on April 19, 1870[5] and was named for the Asia Minor country populated by Phrygians.[6] The Lydia family of asteroids is named after it.

Observations made during 1958–1959 at the McDonald Observatory and in 1969 at the Kitt Peak National Observatory found an uneven light curve with a period of 10.9267 hours.[7] In the late 1990s, a network of astronomers worldwide used light curves to derive spin states and shape models of 10 new asteroids, including (110) Lydia. They obtained a period of 10.92580 hours, with the brightness varying by no more than 0.2 in magnitude.[3]

In the Tholen classification system, it is categorized as an M-type asteroid, while the Bus asteroid taxonomy system lists it as an Xk asteroid.[8] Absorption features in the near infrared are attributed to low-iron, low-calcium orthopyroxene minerals. Water content on the surface is estimated at 0.14–0.27 by mass fraction (wt%).[9] Measurements of the thermal inertia of 110 Lydia give a value between 70 and 200 J m−2 K−1 s–1/2, compared to 50 for lunar regolith and 400 for coarse sand in an atmosphere.[2] It is a likely interloper in the Padua family of minor planets that share similar dynamic properties.[10]

Lydia occulted a dim star on September 18, 1999.

References[edit]

  1. ^ Yeomans, Donald K., "110 Lydia", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), retrieved 2013-03-25. 
  2. ^ a b c d Delbo', Marco; Tanga, Paolo (February 2009), "Thermal inertia of main belt asteroids smaller than 100 km from IRAS data", Planetary and Space Science 57 (2): 259–265, arXiv:0808.0869, Bibcode:2009P&SS...57..259D, doi:10.1016/j.pss.2008.06.015. 
  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 DeMeo, Francesca E. et al. (2011), "An extension of the Bus asteroid taxonomy into the near-infrared", Icarus 202 (1): 160–180, Bibcode:2009Icar..202..160D, doi:10.1016/j.icarus.2009.02.005, retrieved 2013-12-11.  See appendix A.
  5. ^ "Numbered Minor Planets 1–5000", Discovery Circumstances (IAU Minor Planet center), retrieved 2013-04-07. 
  6. ^ Schmadel, Lutz D. (2003), Dictionary of Minor Planet Names (5th ed.), Springer, p. 23, ISBN 3-540-00238-3. 
  7. ^ Taylor, R. C. et al. (March 1971), "Minor Planets and Related Objects. VI. Asteroid (110) Lydia", Astronomical Journal 76: 141, Bibcode:1971AJ.....76..141T, doi:10.1086/111097. 
  8. ^ DeMeo, Francesca E. et al. (July 2009), "An extension of the Bus asteroid taxonomy into the near-infrared", Icarus 202 (1): 160–180, Bibcode:2009Icar..202..160D, doi:10.1016/j.icarus.2009.02.005, retrieved 2013-04-08.  See appendix A.
  9. ^ 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. 
  10. ^ Carruba, V. (May 2009), "The (not so) peculiar case of the Padua family", Monthly Notices of the Royal Astronomical Society 395 (1): 358–377, Bibcode:2009MNRAS.395..358C, doi:10.1111/j.1365-2966.2009.14523.x.