| Discovery[1] | |
|---|---|
| Discovered by | K. Korlević |
| Discovery site | Višnjan Obs. |
| Discovery date | 14 March 1999 |
| Designations | |
| (10645) Brač | |
Named after | Brač(Croatian island)[2] |
| 1999 ES4 · 1962 TN 1968 BF · 1975 TJ1 1980 YK · 1986 EH5 1988 SX4 | |
| main-belt · Eunomia[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 54.67 yr (19,968 days) |
| Aphelion | 3.1430AU |
| Perihelion | 2.1725 AU |
| 2.6578 AU | |
| Eccentricity | 0.1826 |
| 4.33yr (1,583 days) | |
| 224.98° | |
| 0° 13m 39s / day | |
| Inclination | 12.520° |
| 351.57° | |
| 44.961° | |
| Physical characteristics | |
| Dimensions | 9.60 km(calculated)[3] 10.26±0.11 km[4] |
| 2.785±0.005h[5] 2.78592±0.00003 h[6] | |
| 0.202±0.038[4] 0.21(assumed)[3] | |
| S[3] · LS[7] | |
| 12.5[1] · 12.4[3] · 12.3[4] · 12.41±0.50[7] | |
10645 Brač, provisional designation1999 ES4, is a stony Eunomiaasteroid from the central region of theasteroid belt, approximately 10 kilometers in diameter. It was discovered on 14 March 1999, by Croatian astronomerKorado Korlević atVišnjan Observatory, and named after the Croatian island ofBrač.[2][8]
The asteroid is a member of theEunomia family, a large group ofS-type asteroids and the most prominent family in the intermediate main-belt. It orbits the Sun at a distance of 2.2–3.1 AU once every 4 years and 4 months (1,583 days). Its orbit has aneccentricity of 0.18 and aninclination of 13° with respect to theecliptic.[1] The firstprecovery was taken at the U.S.Goethe Link Observatory in 1962, extending the asteroid'sobservation arc by 37 years prior to discovery.[8]
In October 2014,photometric observations by Italian astronomerSilvano Casulli gave a rotationallightcurve with aperiod of2.78592±0.00003 hours and a brightness amplitude of 0.31 inmagnitude (U=3-).[6] Three weeks later, a second lightcurve was obtained at the U.S. Etscorn Campus Observatory in New Mexico, rendering a concurring period of2.785±0.005 with an identical variation in brightness (U=3-).[5]
According to the survey carried out by NASA's space-basedWide-field Infrared Survey Explorer with its subsequentNEOWISE mission, the asteroid measures 10.3 kilometers in diameter and its surface has analbedo of0.202±0.038,[4] while theCollaborative Asteroid Lightcurve Link assumes an albedo of 0.21 and calculates a diameter of 9.6 kilometers.[3] A large-scale survey byPan-STARRS (PS1) assigns an LS-type, an intermediaryspectral type between the common, stony S-types and the rather rare and reddishL-type asteroids.[7]
Thisminor planet was named after theCroatian island ofBrač, the largestDalmatian island in theAdriatic Sea, and the place where theBlaca hermitage Observatory is located.[2] The approved naming citation was published by theMinor Planet Center on 15 December 2005 (M.P.C. 55720).[9]
