Discovered by A. Galád
D. Kalmančok MPC designation 11118 Modra Minor planet category main-belt · Flora Aphelion 2.5 m Asteroid family Flora family Asteroid group Asteroid belt | Discovery date 9 August 1996 Alternative names 1996 PK · 1991 FL1 Discovered 9 August 1996 Orbits Sun Discovery site Modra Observatory | |
Named after Modra
(town and observatory) Discoverers Adrián Galád, Dušan Kalmančok | ||
11118 Modra, provisional designation 1996 PK, is a Flora asteroid of uncertain composition from the inner regions of the asteroid belt, approximately 5 kilometers in diameter. It was discovered on 9 August 1996, by Slovak astronomers Adrián Galád and Dušan Kalmančok at the Modra Observatory in Slovakia.
It is a member of the Flora family, one of the largest orbital groups of stony asteroids in the main-belt. It orbits the Sun at a distance of 2.1–2.5 AU once every 3 years and 6 months (1,285 days). Its orbit has an eccentricity of 0.08 and an inclination of 3° with respect to the ecliptic. The first precovery was taken at ESO's La Silla Observatory in 1991, extending the asteroid's observation arc by 5 years prior to its discovery.
In September 2010, a photometric light-curve analysis by American astronomer Brian Warner at his U.S. Palmer Divide Observatory in Colorado, rendered an unambiguous period of 7001271200000000000♠27.12±0.02 hours with a brightness variation of 0.53 in magnitude (U=3). A second light-curve obtained from the wide-field survey at the U.S. Palomar Transient Factory in August 2010, gave a period of 7001271481000000000♠27.1481±0.0409 hours with an amplitude of 0.42 (U=2).
According to the survey carried out by NASA's Wide-field Infrared Survey Explorer and its subsequent NEOWISE mission, the asteroid has a low albedo of 0.05. In agreement, the large-scale survey by Pan-STARRS (PS1) rates it as a dark carbonaceous body. However, the Collaborative Asteroid Lightcurve Link (CALL) assumes a much higher albedo of 0.24 – derived from 8 Flora, the orbital family's largest member and namesake – and groups it to the S-type asteroid. The different albedos of the two spectral classes also translate into divergent estimates for the body's diameter. While CALL calculates 3.7 kilometers, NASA's space-based survey inferred a much larger diameter of 8.7 kilometers.
The minor planet was named after both the small historical town of Modra, located in the Bratislava Region of Slovakia, and the Modra Observatory of the Institute of Astronomy at Comenius University, where this asteroid had been discovered. Naming citation was published on 28 September 1999 (M.P.C. 36130).