| Discovery[1] | |
|---|---|
| Discovered by | L. Brožek |
| Discovery site | Kleť Obs. |
| Discovery date | 21 August 1981 |
| Designations | |
| (3102) Krok | |
Named after | Duke Krok (legendary Czech figure)[2] |
| 1981 QA | |
| NEO · Amor[1][3] | |
| Orbital characteristics[1] | |
| Epoch 16 February 2017 (JD 2457800.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 35.44 yr (12,944 days) |
| Aphelion | 3.1174AU |
| Perihelion | 1.1839 AU |
| 2.1506 AU | |
| Eccentricity | 0.4495 |
| 3.15yr (1,152 days) | |
| 86.843° | |
| 0° 18m 45s / day | |
| Inclination | 8.4439° |
| 172.09° | |
| 154.78° | |
| Earth MOID | 0.1840 AU · 71.7LD |
| Physical characteristics | |
| Dimensions | 1.48 km(derived)[4] 1.6 km[1] |
| 147.8±0.3h[5] 149.4±1 h[6] 151.8[6] | |
| 0.20(assumed)[4] | |
| QRS(Tholen)[1] S(SMASS)[1] Sqw[7] · QRS[4] B–V = 0.834[1] U–B = 0.521[1] | |
| 16.14±0.2(R)[6] · 16.2[1] · 16.40±0.15[5] · 16.47±0.35[8] · 16.524±0.15[4][9] | |
3102 Krok, provisional designation1981 QA, is a rare-typeasteroid andslow rotator, classified as anear-Earth object of theAmor group, that measures approximately 1.5 kilometers in diameter.
It was discovered on 21 August 1981, by Slovak astronomerLadislav Brožek atKleť Observatory in the Czech Republic.[3] The asteroid was named afterDuke Krok, a legendary Czech figure.[2]
Krok orbits the Sun at a distance of 1.2–3.1 AU once every 3 years and 2 months (1,152 days). Its orbit has aneccentricity of 0.45 and aninclination of 8° with respect to theecliptic.[1] The body'sobservation arc begins with its official discovery observation at Klet, as noprecoveries were taken and no prior identifications were made.[3]
It has an Earthminimum orbital intersection distance of 0.1840 AU (27,500,000 km), which translates into 71.7lunar distances.[1]
In theTholen classification,Krok is characterized as a rare QRS-type. In theSMASS taxonomy it is classified as a commonS-type asteroid, and the "ExploreNEOs" Warm Spitzer program assigns a transitional Sqw-type.[1][7] TheR- andQ-types also belong to the larger group of stony asteroids.
In September 1991, a first rotationallightcurve ofKrok was obtained by American astronomer Alan Harris. Lightcurve analysis gave an exceptionally longrotation period of 147.8 hours with a brightness amplitude of 1.0magnitude, which indicates that the body has a non-spheroidal shape (U=3).[5]
Between 2000 and 2005, severalphotometric observations made by Czech astronomerPetr Pravec gave a similar period between 149.4 and 151.8 and an amplitude of 0.7 to 1.3 (U=3/3-).[6] This makesKrok asslow rotator.
According toTom Gehrels' 1994 publication "Hazards due to Comets and Asteroids",Krok measures 1.6 kilometers in diameter based on a generic surfacealbedo of 0.15,[1] while theCollaborative Asteroid Lightcurve Link assumes a standard albedo for stonyS-type asteroids of 0.20 and calculates a diameter of 1.48 kilometers with anabsolute magnitude of 16.5.[4]
Thisminor planet was named afterDuke Krok, a legendary figure in Czech history, and the first judge ("duke") of the Slavonic tribes in ancient Bohemia. He was also the father ofPrincess Libuše, who, together with her husband Přemysl founded thePřemyslid dynasty of Czech royalty.[2] The official naming citation was published on 18 December 1994 (M.P.C.24410).[10]
