| Discovery[1] | |
|---|---|
| Discovered by | C. S. Shoemaker E. M. Shoemaker |
| Discovery site | Palomar Obs. |
| Discovery date | 12 February 1985 |
| Designations | |
| (6084) Bascom | |
Named after | Florence Bascom (American geologist)[2] |
| 1985 CT · 1978 EC6 1992 BM1 | |
| main-belt · Phocaea[3][4] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 67.22 yr (24,553 days) |
| Aphelion | 2.8582AU |
| Perihelion | 1.7697 AU |
| 2.3139 AU | |
| Eccentricity | 0.2352 |
| 3.52yr (1,286 days) | |
| 163.37° | |
| 0° 16m 48s / day | |
| Inclination | 22.999° |
| 147.24° | |
| 258.81° | |
| Knownsatellites | 1(P: 43.5 h; 0.37 Ds/Dp)[5][a] |
| Physical characteristics | |
| Dimensions | 6.17±1.15 km[6] 6.347±0.218 km[7][8] 6.388 km[9] 6.39 km(taken)[3] |
| 2.74516±0.00002 h[10] 2.7454±0.0005h[5] 2.74542 h[3] 2.74544±0.00002 h[b] | |
| 0.2091[3][9] 0.220±0.030[7][8] 0.26±0.10[6] | |
| S[3] | |
| 12.8±0.1(R)[5] · 12.80±0.03(R)[10] · 12.9[1] · 12.91±0.34[11] · 13.19[6] · 13.25[7] · 13.29±0.058[3][9] | |
6084 Bascom, provisional designation1985 CT, is abinary[a] Phocaeaasteroid from the inner regions of theasteroid belt, approximately 6.3 kilometers in diameter. It was discovered on 12 February 1985, by American astronomer coupleCarolyn andEugene Shoemaker atPalomar Observatory in California.[12] It is named after American geologistFlorence Bascom.[2] Itssatellite measures approximately 2.3 kilometers (0.37 Ds/Dp) and has an orbital period of 43.51 hours.[5]
Bascom is a stonyS-type asteroid and member of thePhocaea family (701),[4] a group of asteroids with similar orbital characteristics. It orbits the Sun in theinner main-belt at a distance of 1.8–2.9 AU once every 3 years and 6 months (1,286 days). Its orbit has aneccentricity of 0.24 and aninclination of 23° with respect to theecliptic.[1] A firstprecovery was taken at Palomar in 1950, extending the body'sobservation arc by 30 years prior to its official discovery observation.[12]
According to the survey carried out by NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Bascom measures 6.17 and 6.347 kilometers in diameter and its surface has analbedo of 0.22 and 0.26, respectively.[6][7][8] TheCollaborative Asteroid Lightcurve Link (CALL) adoptsPetr Pravec's revised WISE-data, that is, an albedo of 0.2091 and a diameter of 6.39 kilometers for anabsolute magnitude of 13.29.[3][9]
Between 29 December 2005 and 2 February 2006, the first ever rotationallightcurve was obtained from photometric observations taken by astronomersDavid Higgins at Hunters Hill Observatory, Australia, by Petr Pravec,Peter Kušnirák, andLenka Šarounová atOndřejov Observatory, Czech Republic, and byŠtefan Gajdoš,Adrián Galád andJozef Világi atModra Observatory, Slovakia.[5][a]
The observations revealed, thatBascom is a synchronousbinary asteroid that has amoon orbiting its primary every 43.5 hours. Mutualasteroid occultation and eclipsing events with amagnitude between 0.12 and 0.18 suggest, that the satellite's diameter is37±2% of that ofBascom (a secondary-to-primary diameter ratio of 0.37), which translates into a mean-diameter of 2.3 kilometers for the minor-planet moon. The photometric observations had an average absolute magnitude of 12.8.[5][a]
SinceBascom's first observation in December 2005, astronomer Peter Pravec has obtained additional lightcurves. They gave a refinedrotation period for the primary of 2.74516 to 2.74544 hours with a brightness variation between 0.14 and 0.23 magnitude (U=3/3/3).[10][b] These observations also confirmed the presence of the satellite giving a concurringorbital period of 43.51 hours.[10] For an asteroid of its size,Bascom has a relatively fast spin rate, but still above those offast rotators. CALL adopts a rotation period of 2.74542 hours.[3]
Thisminor planet was named in memory ofFlorence Bascom (1862–1945), the second woman to earn her Ph.D. in geology in the United States. She was also the first woman hired by theUnited States Geological Survey and the first woman elected to the Council of theGeological Society of America. Bascom founded the geology department atBryn Mawr College, Pennsylvania, where she taught the next generation of notable female geologists for 33 years. Expert inpetrography,mineralogy andcrystallography, her research focused ongeomorphology.[2] The approved naming citation was published by theMinor Planet Center on 11 April 1998 (M.P.C. 31610).[13]
