| Discovery[1] | |
|---|---|
| Discovered by | C. Shoemaker S. J. Bus |
| Discovery site | Palomar Obs. |
| Discovery date | 24 May 1982 |
| Designations | |
| (4029) Bridges | |
Named after | Patricia M. Bridges (planetary cartographer)[2] |
| 1982 KC1 · 1974 HS2 1975 TQ · 1978 AF 1978 JJ2 · 1982 OX 1986 JF | |
| main-belt · (middle)[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 42.93 yr (15,680 days) |
| Aphelion | 2.8575AU |
| Perihelion | 2.1925 AU |
| 2.5250 AU | |
| Eccentricity | 0.1317 |
| 4.01yr (1,466 days) | |
| 287.79° | |
| 0° 14m 44.16s / day | |
| Inclination | 5.4383° |
| 214.78° | |
| 16.729° | |
| Knownsatellites | 1[4][5][a] (D: 1.87 km;P: 16.317 h) |
| Physical characteristics | |
| Dimensions | 7.433±0.122 km[6] 7.91 km[7] 8.015±0.073 km[8] |
| 3.57459±0.0001 h[9] 3.5746±0.0001 h[5] 3.5748±0.0002 h[10] 3.57491±0.0003 h[b] 3.6941±0.0002h[11] | |
| 0.1848[7] 0.2007±0.0148[8] 0.265±0.036[6] | |
| S[12][3] | |
| 12.40±0.10(R)[9] · 12.49±0.02(R)[b] · 12.8[1] · 12.85[8] · 12.96±0.094[3][7] · 13.03±0.50[12] | |
4029 Bridges, provisional designation1982 KC1, is a stonyasteroid andbinary system from the middle regions of theasteroid belt, approximately 8 kilometers in diameter.
It was discovered on 24 May 1982, by American astronomersCarolyn Shoemaker andSchelte Bus atPalomar Observatory, California, and named after AmericanUSGS planetary cartographer Patricia M. Bridges.[2][13]
Bridges is a stonyS-type asteroid that orbits the Sun in the middle main-belt at a distance of 2.2–2.9 AU once every 4.01 years (1,466 days). Its orbit has aneccentricity of 0.13 and aninclination of 5° with respect to theecliptic.[1] With asemi-major axis of 2.525 AU,Bridges is near the main-belt'sKirkwood gap at 2.5 AU, which corresponds to the 3:1orbital resonance with the gas giantJupiter. It is, however, not a member of theAlinda family due to its much lower eccentricity.
It was first identified as1974 HS2 at the ChileanCerro El Roble Observatory in 1974, extending the body'sobservation arc by 8 years prior to its official discovery observation at Palomar.[13]
In May 2002, a first rotationallightcurve ofBridges was obtained from photometric observations by French amateur astronomersRené Roy andLaurent Bernasconi. Lightcurve analysis gave a well-definedrotation period of 3.6941 hours with a brightness variation of 0.24magnitude (U=3).[11]
A large number of observations have followed since 2006, when a satellite in orbit ofBridges was discovered (see below).[a] Between 2007 and 2012, several observation by astronomersPetr Pravec and gave a period between 3.57459 and 3.5754 hours with an amplitude between 0.18 and 0.29 magnitude (U=3/3/3/3/3).[9][10][c][d][e][b]
According to the survey carried out by NASA'sWide-field Infrared Survey Explorer (WISE) with its subsequentNEOWISE mission,Bridges measures 7.433 and 8.015 kilometers in diameter and its surface has analbedo of 0.265 and 0.2007, respectively.[6][8] TheCollaborative Asteroid Lightcurve Link adopts Petr Pravec's revised WISE-data, that is, an albedo of 0.1848 and a diameter of 7.91 kilometers with anabsolute magnitude of 12.96.[3][7]
In April and May 2006,Bridges was observed by astronomersDavid Higgins at Hunters Hill Observatory (E14), Australia, Petr Pravec andPeter Kušnirák atOndřejov Observatory Czech Republic,Walter R. Cooney Jr.,John Gross and Dirk Terrell at Sonoita Research Observatory (G94), United States, andRobert Stephens at Santana Observatory(646), United States.[a]
The observed mutual occultation/eclipsing events revealed, thatBridges is abinary asteroid, that is orbited every16.31±0.01 hours by aminor-planet moon.[5][a] A refinedorbital period of 16.317 hours was later published.[3][9] Based on the system's secondary-to-primary mean-diameter ratio of0.24±0.02,[5] the satellite measures approximately1.87±0.16 kilometers in diameter.[4] Johnston's Archive also estimates a semi-major axis of 13 kilometers for the moon's orbit.[4]
Thisminor planet was named after Patricia M. Bridges, planetary cartographer with theUnited States Geological Survey. Bridges has created detailed maps of several planetary body's surface features, and has been an airbrushing expert for shaded lunar relief maps based on spacecraft images.[2] The approved naming citation was published by theMinor Planet Center on 12 December 1989 (M.P.C. 15576).[14]
