| Discovery[1] | |
|---|---|
| Discovered by | E. Helin |
| Discovery site | Palomar Obs. |
| Discovery date | 4 October 1986 |
| Designations | |
| (4209) Briggs | |
Named after | Geoffrey A. Briggs (Americanspace physicist)[2][3] |
| 1986 TG4 · 1969 SB 1978 EL8 · 1986 WD5 1989 CO4 | |
| main-belt · (outer)[4] Alauda[5] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 47.53 yr (17,360 days) |
| Aphelion | 3.4213AU |
| Perihelion | 2.8916 AU |
| 3.1565 AU | |
| Eccentricity | 0.0839 |
| 5.61yr (2,048 days) | |
| 195.76° | |
| 0° 10m 32.88s / day | |
| Inclination | 21.614° |
| 330.37° | |
| 12.512° | |
| Physical characteristics | |
| Dimensions | 25.39 km(derived)[4] 25.63±2.3 km(IRAS:2)[6] 28.92±0.71 km[7] 29.62±0.61 km[8] 30.895±0.239 km[9] 31.303±0.128[10] |
| 12.22±0.02 h[11] 12.235±0.01h[12] 12.2530±0.0005 h[13] | |
| 0.067±0.013[8] 0.0827(derived)[4] 0.0889±0.0256[9] 0.093±0.012[10] 0.103±0.006[7] 0.1288±0.026(IRAS:2)[6] | |
| C[4] | |
| 10.8[6][7][9] · 11.20[8] · 11.3[1][4] · 11.57±0.42[14] | |
4209 Briggs, provisional designation1986 TG4, is a carbonaceous Alaudaasteroid from the outer region of theasteroid belt, approximately 28 kilometers in diameter. It was discovered on 4 October 1986, by American astronomerEleanor Helin at thePalomar Observatory in California, United States.[15] The asteroid was named after American space physicistGeoffrey A. Briggs.[2]
Briggs is a member of theAlauda family (902),[5] a largefamily of typically bright carbonaceous asteroids and named after its parent body,702 Alauda.[16]: 23
It orbits the Sun in theouter main-belt at a distance of 2.9–3.4 AU once every 5 years and 7 months (2,048 days). Its orbit has aneccentricity of 0.08 and aninclination of 22° with respect to theecliptic.[1] The firstprecovery was obtained atEl Leoncito in 1969, extending the asteroid'sobservation arc by 17 years prior to its discovery.[15]
A rotationallightcurves of this asteroid was obtained from photometric observations made by American astronomerBrian Warner at his Palmer Divide Observatory (716) in September 2003. The revised lightcurve showed arotation period of12.22 hours with a brightness variation of 0.45 inmagnitude (U=3-).[11] A second lightcurve from a collaboration of Czech, American and Italian observatories published in November 2013, gave a period of12.2530 hours (U=n/a).[13]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite, and NASA'sWide-field Infrared Survey Explorer with itsNEOWISE mission, the asteroid measures between 25.6 and 31.3 kilometers in diameter and its surface has an albedo in the range of 0.07 to 0.13.[6][7][9][8][10] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.08 and a diameter of 25.4 kilometer, slightly below the result obtained by IRAS.[4]
Thisminor planet was named after Americanspace physicist Geoffrey A. Briggs, director of the Solar System Exploration Division at NASA Headquarters during the 1980s. He was instrumental for the formation of the U.S.–Soviet Joint Working Group for Solar System Exploration and became its co-chairman. He was on the imaging teams for theMariner,Viking andVoyager missions.[3] Briggs continued to promote space-related accomplishments to the public at theAir and Space Museum.[2] The approved naming citation was published by theMinor Planet Center on 27 June 1991 (M.P.C. 18456).[17]
