969 Leocadia
Main-belt asteroid
From Wikipedia, the free encyclopedia
969 Leocadia (prov. designation: A921 VC or 1921 KZ) is a very dark background asteroid from the inner regions of the asteroid belt, approximately 19 kilometers (12 miles) in diameter. It was discovered on 5 November 1921, by Russian astronomer Sergey Belyavsky at the Simeiz Observatory on the Crimean peninsula.[1] The uncommon F-type asteroid (FX) has a rotation period of 6.9 hours and is likely regular in shape.[10] Any reference of the asteroid's name to a person is unknown.[3]
| Discovery[1] | |
|---|---|
| Discovered by | S. Belyavskyj |
| Discovery site | Simeiz Obs. |
| Discovery date | 5 November 1921 |
| Designations | |
| (969) Leocadia | |
| Pronunciation | /liːoʊˈkeɪdiə/[2] |
Named after | unknown[3] |
| A921 VC · 1940 RV 1944 SB · 1948 UG 1963 PA · 1921 KZ | |
| main-belt[1][4] · (inner) background[5][6] | |
| Orbital characteristics[4] | |
| Epoch 31 May 2020 (JD 2459000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 98.12 yr (35,837 d) |
| Aphelion | 2.9694 AU |
| Perihelion | 1.9537 AU |
| 2.4615 AU | |
| Eccentricity | 0.2063 |
| 3.86 yr (1,411 d) | |
| 199.53° | |
| 0° 15m 18.72s / day | |
| Inclination | 2.2928° |
| 287.76° | |
| 91.332° | |
| Physical characteristics | |
| 6.87±0.01 h[10][11] | |
| 12.8[1][4] | |
Orbit and classification
Leocadia is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements.[5][6] It orbits the Sun in the inner main-belt at a distance of 2.0–3.0 AU once every 3 years and 10 months (1,411 days; semi-major axis of 2.46 AU). Its orbit has an eccentricity of 0.21 and an inclination of 2° with respect to the ecliptic.[4] The body's observation arc begins at Uccle Observatory in February 1933, more than a decade after its official discovery observation Simeiz Observatory on 5 November 1921.[1]
Naming
This minor planet is named after a Feminine Russian first name. Any reference of this name to a person or occurrence is unknown.[3]
Unknown meaning
Among the many thousands of named minor planets, Leocadia is one of 120 asteroids, for which no official naming citation has been published. All of these low-numbered asteroids have numbers between 164 Eva and 1514 Ricouxa and were discovered between 1876 and the 1930s, predominantly by astronomers Auguste Charlois, Johann Palisa, Max Wolf and Karl Reinmuth.[12]
Physical characteristics
In the Tholen classification (FXU:), Leocadia is an uncommon and dark F-type asteroid, somewhat similar to that of an X-type, though with an unusual (U) and noisy (:) spectra.[4]
Rotation period
In December 2006, a rotational lightcurve of Leocadia was obtained from photometric observations by Italian amateur astronomers Roberto Crippa and Federico Manzini at the Sozzago Astronomical Station (A12). Lightcurve analysis gave a rotation period of 6.87±0.01 hours with a brightness amplitude of 0.14±0.01 magnitude (U=2), which is indicative of a rather spherical, non-irregular shape.[10][11]
Diameter and albedo
According to the surveys carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), the Japanese Akari satellite, and the Infrared Astronomical Satellite IRAS, Leocadia measures 17.321±0.218, 19.37±0.22 and 19.51±0.7 kilometers in diameter, and its surface has a very low albedo of 0.019±0.005, 0.0435±0.003 and 0.045±0.001, respectively.[7][8][9] Additional measurements by the WISE telescope were published giving a mean diameter as low as 13.58±3.09 km.[11] The Collaborative Asteroid Lightcurve Link adopts the result from IRAS, that is, an albedo of 0.0435 and a diameter of 19.51 kilometers based on an absolute magnitude of 9.22.[11]
An asteroid occultation on 19 August 2013, gave a best-fit ellipse dimension of 19.0 × 19.0 kilometers.[6] These timed observations are taken when the asteroid passes in front of a distant star. However the measurements for Leocadia were of poor quality.[6]
