110 Lydia
Main-belt asteroid
From Wikipedia, the free encyclopedia
110 Lydia is a large belt asteroid with an M-type spectrum,[5] and thus may be metallic in composition, consisting primarily of nickel-iron. It was discovered by French astronomer Alphonse Borrelly on 19 April 1870[6] and was named for Lydia, the Asia Minor country populated by Phrygians.[7] The Lydia family of asteroids is named after it.
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Lightcurve-based 3D-model of Lydia | |
| Discovery | |
|---|---|
| Discovered by | Alphonse Borrelly |
| Discovery date | 19 April 1870 |
| Designations | |
| (110) Lydia | |
| Pronunciation | /ˈlɪdiə/[1] |
Named after | Lydia |
| A870 HA; 1899 VA; 1972 YS1 | |
| Orbital characteristics[2] | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 145.80 yr (53,255 d) |
| Aphelion | 2.9539 AU (441.90 Gm) |
| Perihelion | 2.51115 AU (375.663 Gm) |
| 2.7325 AU (408.78 Gm) | |
| Eccentricity | 0.081021 |
| 4.52 yr (1649.9 d) | |
Average orbital speed | 17.99 km/s |
| 348.344° | |
| 0° 13m 5.52s / day | |
| Inclination | 5.9645° |
| 56.871° | |
| 283.499° | |
| TJupiter | 3.341 |
| Physical characteristics | |
| Dimensions | |
| Mass | 6.7×1017 kg |
Equatorial surface gravity | 0.0241 m/s2 |
Equatorial escape velocity | 0.0455 km/s |
| Temperature | ~168 K |
| 7.80[2][3] | |
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.[8] 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.[4]
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.[9] 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%).[10] 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.[3] It is a likely interloper in the Padua family of minor planets that share similar dynamic properties.[11]
