| Discovery[1] | |
|---|---|
| Discovered by | R. M. West |
| Discovery site | La Silla Obs. |
| Discovery date | 24 October 1976 |
| Designations | |
| (2145) Blaauw | |
Named after | Adriaan Blaauw[2] (Dutch astronomer) |
| 1976 UF · 1929 XS 1963 RK · 1980 TW | |
| main-belt · (outer)[1][3] Ursula[4] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 41.02 yr (14,983 days) |
| Aphelion | 3.5269AU |
| Perihelion | 2.9059 AU |
| 3.2164 AU | |
| Eccentricity | 0.0965 |
| 5.77yr (2,107 days) | |
| 314.16° | |
| 0° 10m 15.24s / day | |
| Inclination | 15.013° |
| 264.34° | |
| 279.04° | |
| Physical characteristics | |
| Dimensions | 34.06 km(derived)[3] 37.11±0.53 km[5] 38.00±10.68 km[6] 40.549±0.848 km[7] 40.55±0.85 km[7] |
| 12.141±0.003h[8] | |
| 0.051±0.011[7] 0.06±0.04[6] 0.0665(derived)[3] 0.076±0.002[5] | |
| C(assumed)[3] | |
| 10.60[5] · 10.80[6][7] · 10.83±0.34[9] · 10.9[1][3] | |
2145 Blaauw, provisional designation1976 UF, is a dark Ursulaasteroid from the outer regions of theasteroid belt, approximately 38 kilometers in diameter. It was discovered on 24 October 1976, by astronomerRichard Martin West at theLa Silla Observatory in northern Chile.[10] The asteroid was named after Dutch astronomerAdriaan Blaauw.[2]
Blaauw is a member of theUrsula family (631),[4] a largefamily ofC- andX-type asteroids, named after its parent body,375 Ursula.[11] It orbits the Sun in theouter asteroid belt at a distance of 2.9–3.5 AU once every 5 years and 9 months (2,107 days;semi-major axis of 3.22 AU). Its orbit has aneccentricity of 0.10 and aninclination of 15° with respect to theecliptic.[1]
The asteroid was first identified as1929 XS atLowell Observatory in December 1929. The body'sobservation arc begins with its identification as1963 RK at theKarl Schwarzschild Observatory in September 1963, or 13 years prior to its official discovery observation at La Silla.[10]
Blaauw is an assumed, carbonaceousC-type asteroid.[3]
Photometric measurements made from theOakley Southern Sky Observatory during 2012 gave alightcurve with a period of 12.141 ± 0.003 hours and a variation in brightness of 0.18 ± 0.03 inmagnitude (U=2+).[8]
According to the surveys carried out by the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Blaauw measures between 37.11 and 40.55 kilometers in diameter and its surface has analbedo between 0.051 and 0.076.[5][6][7]
TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.0665 and a diameter of 34.06 kilometers based on anabsolute magnitude of 10.9.[3]
Thisminor planet was named after Dutch astronomerAdriaan Blaauw (1914–2010), who was director of theEuropean Southern Observatory (1970–74), president of theInternational Astronomical Union (1976–79) and professor at theLeiden Observatory (1975–1981). His study included the structure of theMilky Way andstellar kinematics and associations.[2] The officialnaming citation was published by theMinor Planet Center on 1 July 1979 (M.P.C. 4788).[12]
