| Discovery[1] | |
|---|---|
| Discovered by | A. Galád D. Kalmančok |
| Discovery site | Modra Obs. |
| Discovery date | 9 August 1996 |
| Designations | |
| (11118) Modra | |
Named after | Modra (town andobservatory)[2] |
| 1996 PK · 1991 FL1 | |
| main-belt · Flora[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 25.44 yr (9,291 days) |
| Aphelion | 2.5052AU |
| Perihelion | 2.1225 AU |
| 2.3139 AU | |
| Eccentricity | 0.0827 |
| 3.52yr (1,286 days) | |
| 139.39° | |
| 0° 16m 48s / day | |
| Inclination | 3.0326° |
| 7.4717° | |
| 204.63° | |
| Physical characteristics | |
| Dimensions | 3.74 km(calculated)[3] 8.69±3.13 km[4] |
| 27.12±0.02h[5] 27.1481±0.0409 h[6] | |
| 0.054±0.105[4] 0.24(assumed)[3] | |
| S[3] · C[7] | |
| 14.3[1][3] · 14.211±0.005(R)[6] · 14.17±0.36[7] · 14.10[4] | |
11118 Modra (provisional designation1996 PK) is a Floraasteroid of uncertain composition from the inner regions of theasteroid belt, approximately 5 kilometers in diameter.
It was discovered on 9 August 1996, by Slovak astronomersAdrián Galád andDušan Kalmančok at theModra Observatory in Slovakia, and named for the townModra where the discovering observatory is located.[2][8]
Modra is a member of theFlora family, one of the largest families ofstony asteroids. It orbits the Sun in theinner main-belt at a distance of 2.1–2.5 AU once every 3 years and 6 months (1,286 days). Its orbit has aneccentricity of 0.08 and aninclination of 3° with respect to theecliptic.[1] A firstprecovery was taken at ESO'sLa Silla Observatory in 1991, extending the asteroid'sobservation arc by 5 years prior to its discovery.[8]
In September 2010, a photometriclightcurve analysis of Modra by American astronomerBrian Warner at his Palmer Divide Observatory, Colorado, rendered an unambiguousperiod of27.12±0.02 hours with a brightness variation of 0.53 inmagnitude (U=3).[5] A second lightcurve obtained during the wide-field survey at the U.S.Palomar Transient Factory in August 2010, and gave a period of27.1481±0.0409 hours with an amplitude of 0.42 (U=2).[6]
According to the survey carried out by NASA'sWide-field Infrared Survey Explorer and its subsequentNEOWISE mission, the asteroid has a lowalbedo of 0.05.[4] In agreement, the large-scale survey byPan-STARRS (PS1) rates it as a darkcarbonaceous body.[7] However, theCollaborative Asteroid Lightcurve Link (CALL) assumes a much higher albedo of 0.24 – derived from8 Flora, the orbital family's largest member and namesake – and groups it to theS-type asteroid.[3] The different albedos of the twospectral 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.[3][4]
Thisminor planet was named after both the small historical town ofModra, located in the Bratislava Region of Slovakia, and theModra Observatory of the Institute of Astronomy at Comenius University, where this asteroid had been discovered.[2] The approved naming citation was published by theMinor Planet Center on 28 September 1999 (M.P.C. 36130).[9]
