| Discovery[1] | |
|---|---|
| Discovered by | E. F. Helin |
| Discovery site | Palomar Obs. |
| Discovery date | 22 January 1990 |
| Designations | |
| (19982) Barbaradoore | |
Named after | Barbara Doore (discoverer's cousin)[2] |
| 1990 BJ · 1983 AD2 | |
| Mars crosser[1][3] main-belt[4] · Phocaea[5] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 33.36 yr (12,186 days) |
| Aphelion | 3.0039AU |
| Perihelion | 1.6657 AU |
| 2.3348 AU | |
| Eccentricity | 0.2866 |
| 3.57yr (1,303 days) | |
| 307.09° | |
| 0° 16m 34.68s / day | |
| Inclination | 22.325° |
| 290.03° | |
| 106.86° | |
| Physical characteristics | |
| Dimensions | 3.88±0.63 km[6] 4.668±0.120 km[7][8] 5.02±0.14 km[9] 5.66 km(calculated)[3] |
| 3.3162±0.0003h[a] | |
| 0.20(assumed)[3] 0.306±0.040[9][8] 0.3540±0.0784[7] 0.42±0.21[6] | |
| S(assumed)[3] | |
| 13.13±0.47[10] · 13.4[7][9] 13.5[6] · 13.6[1][3] | |
19982 Barbaradoore (provisional designation1990 BJ) is an eccentric, stony Phocaeaasteroid and a recentMars-crosser from the inner regions of theasteroid belt, approximately 5 kilometers in diameter. It was discovered on 22 January 1990, by American astronomerEleanor Helin at thePalomar Observatory in California, United States.[4] The asteroid was named after Barbara Doore, a cousin of the discoverer.[2]
When applying theHierarchical Clustering Method to itsproper orbital elements, Barbaradoore is a member of thePhocaea family (701),[5] a largefamily of stonyS-type asteroids with nearly two thousand known members.[11]: 23 It orbits the Sun in theinner main-belt at a distance of 1.7–3.0 AU once every 3 years and 7 months (1,303 days). Its orbit has aneccentricity of 0.29 and aninclination of 22° with respect to theecliptic.[1]
As of 2017, Barbaradoore has become aMars-crossing asteroid (MCA), a dynamically unstable group between themain belt and thenear-Earth populations, because itsperihelion is at 1.6657, declining from 1.6662 AU just the year before. In theJPL Small-Body Database, an asteroid's perihelion has to be smaller than 1.666 AU in order to classify as MCA, while in theLightcurve Data Base, that limit is defined at 1.668 AU.[12][b]
As of 2017, theMinor Planet Center does not classify Barbaradoore as an MCA, due to a differently defined threshold-perihelion of 1.6600 AU.[13] It therefore remains an unspecified main-belt asteroid.[4] Before 2017, when Barbaradoore's orbit did not yet cross that of Mars, it was an outer Mars grazer.
Barbaradoore is an assumed stonyS-type asteroid,[3] which agrees with the overallspectral type for members of thePhocaea family.[11]: 23
In July 2010, a rotationallightcurve of Barbaradoore was obtained from photometric observation by Czech astronomerPetr Pravec atOndřejov Observatory. Lightcurve analysis gave a well-definedrotation period of3.3162 hours with a brightness variation of 0.28magnitude (U=3).[a]
According to the surveys carried out by NASA'sWide-field Infrared Survey Explorer and its subsequentNEOWISE mission, Barbaradoore has a highalbedo between 0.306 and 0.42 with a corresponding diameter of 3.88 to 5.02 kilometers,[6][7][9] while theCollaborative Asteroid Lightcurve Link assumes a standard albedo forstony asteroids of 0.20 and calculates a diameter of 5.66 kilometers with anabsolute magnitude of 13.6.[3]
With a diameter of approximately 5 kilometers, Barbaradoore is one of the smallest sizableMars-crossing asteroids compared to1065 Amundsenia (9.75 km),1139 Atami (9.35 km),1508 Kemi (17 km),1011 Laodamia (7.39 km),1727 Mette (est 9 km),1131 Porzia (7.13 km),1235 Schorria (est. 9 km),985 Rosina (8.18 km)1310 Villigera (15.24 km), and1468 Zomba (7 km); and much smaller than the largest members of this dynamical group, namely,132 Aethra,323 Brucia,2204 Lyyli and512 Taurinensis, which are larger than 20 kilometers in diameter.
Thisminor planet was named after a cousin of the discoverer, Barbara Hendricks Doore (born 1933). She is described by the discoverer as an admirer of sports and as an appreciated leader and volunteer, who has dedicated much of her time atCathedral City's Boys and Girls Club in California.[2] The official naming citation was published by theMinor Planet Center on 24 June 2002(M.P.C. 46012).[14]
