| Discovery[1] | |
|---|---|
| Discovered by | S. Arend |
| Discovery site | Uccle Obs. |
| Discovery date | 1 September 1953 |
| Designations | |
| (1625) The NORC | |
Named after | TheIBM NORC (Naval Ordnance Research Calculator)[2] |
| 1953 RB · 1929 CA 1935 EN · 1936 QS 1942 RK · 1947 NG 1953 QK · 1954 UL1 A914 SA | |
| main-belt · (outer)[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 102.34 yr (37,380 days) |
| Aphelion | 3.9236AU |
| Perihelion | 2.4606 AU |
| 3.1921 AU | |
| Eccentricity | 0.2292 |
| 5.70yr (2,083 days) | |
| 147.86° | |
| 0° 10m 22.08s / day | |
| Inclination | 15.552° |
| 320.78° | |
| 286.20° | |
| Physical characteristics | |
| Dimensions | 44.66±2.09 km[4] 47.60 km(calculated)[3] 53.317±0.176 km[5] 55.863±1.536 km[6] 61.76±17.49 km[7] 75.11±0.80 km[8] |
| 12.94±0.01 h[9] 13.8113±0.0071 h[10] 13.959±0.004h[11] 18.820±0.770 h[12] | |
| 0.023±0.004[8] 0.03±0.02[7] 0.0414±0.0077[6] 0.057(assumed)[3] 0.065±0.006[4] | |
| Tholen =C[1] · C[3] B–V = 0.732[1] U–B = 0.311[1] | |
| 10.043±0.001(R)[10] · 10.070±0.080(R)[12] · 10.34[1][3][4][6][7][8] | |
1625 The NORC (provisional designation1953 RB) is a carbonaceousasteroid from the outer region of theasteroid belt, approximately 55 kilometers in diameter. It was discovered on 1 September 1953, by Belgian astronomerSylvain Arend at theRoyal Observatory of Belgium in Uccle, Belgium.[13] It was named after theIBM Naval Ordnance Research Calculator (NORC).[2]
The NORC orbits the Sun in theouter main-belt at a distance of 2.5–3.9 AU once every 5 years and 8 months (2,083 days). Its orbit has aneccentricity of 0.23 and aninclination of 16° with respect to theecliptic.[1] The asteroid was first identified asA914 SA atHeidelberg Observatory in 1914. Itsobservation arc begins 24 years prior to its official discovery observation, when it was identified as1929 CA at Uccle.[13]
In theTholen classification, The NORC is a common carbonaceousC-type asteroid.[1]
Between 2009 and 2014, five rotationallight-curve were obtained of The NORC from photometric observations taken byRené Roy,David Higgins and thePalomar Transient Factory. The light-curves gave arotation period between 12.94 and 18.820 hours with a change in brightness of 0.06 to 0.33 inmagnitude (U=+1/2/3-).[9][10][12] The best rated result with a period of 13.959 hours (Δmag 0.16) was obtained by Australian amateur astronomer David Higgins.[11]
According to the surveys carried out by JapaneseAkari satellite and NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission, The NORC measures between 44.66 and 75.11 kilometers in diameter, and its surface has analbedo of 0.023 and 0.065.[4][5][6][7][8] TheCollaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 47.60 kilometers using anabsolute magnitude of 10.34.[3]
Thisminor planet was named after theIBM Naval Ordnance Research Calculator (NORC), IBM's first-generation vacuum tube computer built in the 1950s(also seeList of vacuum tube computers and§ External links). NORC was the fastest, most powerful electronic computer of its time. Under the direction ofWallace J. Eckert, after whom the asteroid1750 Eckert is named, NORC performed a vast amount of orbital calculations for minor planet.[2] The officialnaming citation was published by theMinor Planet Center in May 1957 (M.P.C. 1591).[14]
