3102 Krok
3102 Krok, provisional designation, is a rare-type asteroid and slow rotator, classified as a near-Earth object of the Amor group, that measures approximately 1.5 kilometers in diameter.
It was discovered on 21 August 1981, by Slovak astronomer Ladislav Brožek at Kleť Observatory in the Czech Republic. The asteroid was named after Duke Krok, a legendary Czech figure.
Classification and orbit
Krok orbits the Sun at a distance of 1.2–3.1 AU once every 3 years and 2 months. Its orbit has an eccentricity of 0.45 and an inclination of 8° with respect to the ecliptic. The body's observation arc begins with its official discovery observation at Klet, as no precoveries were taken and no prior identifications were made.It has an Earth minimum orbital intersection distance of, which translates into 71.7 lunar distances.
Physical characteristics
In the Tholen classification, Krok is characterized as a rare QRS-type. In the SMASS taxonomy it is classified as a common S-type asteroid, and the "ExploreNEOs" Warm Spitzer program assigns a transitional Sqw-type. The R- and Q-types also belong to the larger group of stony asteroids.Rotation and shape
In September 1991, a first rotational lightcurve of Krok was obtained by American astronomer Alan Harris. Lightcurve analysis gave an exceptionally long rotation period of 147.8 hours with a brightness amplitude of 1.0 magnitude, which indicates that the body has a non-spheroidal shape.Between 2000 and 2005, several photometric observations made by Czech astronomer Petr Pravec gave a similar period between 149.4 and 151.8 and an amplitude of 0.7 to 1.3. This makes Krok as slow rotator.