| Discovery[1] | |
|---|---|
| Discovered by | Indiana University (Indiana Asteroid Program) |
| Discovery site | Goethe Link Obs. |
| Discovery date | 28 January 1950 |
| Designations | |
| (1615) Bardwell | |
Named after | Conrad Bardwell(astronomer)[2] |
| 1950 BW · 1926 TO 1937 TJ · 1948 RB1 1948 RH1 · 1948 TG | |
| main-belt · Themis[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 90.49 yr (33,053 days) |
| Aphelion | 3.6887AU |
| Perihelion | 2.5664 AU |
| 3.1275 AU | |
| Eccentricity | 0.1794 |
| 5.53yr (2,020 days) | |
| 169.71° | |
| 0° 10m 41.52s / day | |
| Inclination | 1.6901° |
| 152.55° | |
| 252.97° | |
| Physical characteristics | |
| Dimensions | 21.92±5.97 km[4] 25.01±1.49 km[5] 27.78±1.6 km(IRAS:5)[6] 28.8±2.9 km[7] 29.139±0.148 km[8] 31±3 km[9] 31.579±0.250 km[10] |
| 18h[a] | |
| 0.0497±0.0192[10] 0.05±0.01[9] 0.060±0.010[8][7] 0.0642±0.008(IRAS:5)[6] 0.079±0.015[5] 0.09±0.06[4] | |
| Tholen =B[1] · B[3] B–V = 0.692[1] U–B = 0.329[1] | |
| 11.38[1][3][5][6][7][9][10] · 11.46[4] | |
1615 Bardwell, provisional designation1950 BW, is a rare-type Themistianasteroid from the outer region of theasteroid belt, approximately 27 kilometers in diameter. It was discovered on 28 January 1950, byIU'sIndiana Asteroid Program atGoethe Link Observatory near Brooklyn, Indiana, United States.[11] It is named for American astronomerConrad Bardwell.[2]
Bardwell is a member of theThemis family, a dynamical family ofouter-belt asteroids with nearly coplanarecliptical orbits. It orbits the Sun at a distance of 2.6–3.7 AU once every 5 years and 6 months (2,020 days). Its orbit has aneccentricity of 0.18 and aninclination of 2° with respect to theecliptic.[1]
Its orbit has aneccentricity of 0.18 and aninclination of 2° with respect to the ecliptic.[1] It was first identified as1926 TO atSimeiz Observatory in 1926, extending the body'sobservation arc by 24 years prior to its official discovery observation.[11]
Thisminor planet was named forConrad M. Bardwell (1926–2010), who was a research associate at theCincinnati Observatory and later associate director of theMinor Planet Center in Cambridge, Massachusetts, United States. Bardwell successfully established numerous identifications from observations in widely separated oppositions and provided observers with reliable data oforbital elements.[2] The officialnaming citation was published by theMinor Planet Center on 15 June 1974 (M.P.C. 3643).[12]
In theTholen taxonomy,Bardwell is a blueishB-type asteroid, a rare subtype of the abundant carbonaceousC-types found in the outer belt. The spectra of B-type bodies show a broadabsorption feature at onemicron wavelength that is associated with the presence ofmagnetite and is what gives the asteroid its blue tint.[13] There are only a few dozens asteroids of this type known to exist.[14]
In the late 1970s, a rotationallightcurve ofBardwell was obtained by American astronomer Edward Tedesco. It gave a provisionalrotation period of 18 hours with a change in brightness of 0.2magnitude (U=1).[a] As of 2017, no other photometric analysis ofBardwell has been made.
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS and NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Bardwell measures between 21.92 and 31.58 kilometers in diameter, and its surface has analbedo between 0.049 and 0.09.[4][6][7][8][10] TheCollaborative Asteroid Lightcurve Link agrees with the results obtained by IRAS, that is, an albedo of 0.0642 and a diameter of 27.78 kilometers based on anabsolute magnitude of 11.38.[3]
