 | |
| Discovery[1] | |
|---|---|
| Discovered by | H. E. Holt |
| Discovery site | Palomar Obs. |
| Discovery date | 22 August 1990 |
| Designations | |
| (9948)1990 QB2 | |
| 1990 QB2 · 1979 SJ6 1990 SQ26 | |
| main-belt[1][2] · (inner)[3] Nysa[4] | |
| Orbital characteristics[2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 38.43yr (14,035 d) |
| Aphelion | 2.9012AU |
| Perihelion | 1.8657 AU |
| 2.3835 AU | |
| Eccentricity | 0.2172 |
| 3.68 yr (1,344 d) | |
| 187.50° | |
| 0° 16m 4.08s / day | |
| Inclination | 2.0964° |
| 171.55° | |
| 151.67° | |
| Physical characteristics | |
| 3.345±0.717 km[5][6] 3.351 km[7] | |
| 3.523±0.0025 h(R)[8] 3.5257±0.0007 h[9] 3.53±0.010 h(R)[10] | |
| 0.2232[7] 0.250±0.093[5][6] | |
| S(SDSS-MOC)[11] S (Pan-STARRS)[12] | |
| 13.79±0.54[12] 14.290±0.200(R)[10] 14.3[2] 14.338±0.004(R)[8] 14.5[6] 14.62[3][7] | |
(9948) 1990 QB2 (provisional designation1990 QB2) is a stonyNysian asteroid from the inner region of theasteroid belt, approximately 3.4 kilometers (2.1 miles) in diameter. It was discovered on 22 August 1990, by American astronomerHenry Holt at thePalomar Observatory in California.[1] The likely elongatedS-type asteroid has arotation period of 3.53 hours.[3] This asteroid has not beennamed.[1]
1990 QB2 is member of theNysa family (405),[4] located in the Nysa–Polana complex. It is named after44 Nysa and one of the largestfamilies in the main belt.[13]: 23
The asteroid orbits the Sun in theinner asteroid belt at a distance of 1.9–2.9 AU once every 3 years and 8 months (1,344 days;semi-major axis of 2.38 AU). Its orbit has aneccentricity of 0.22 and aninclination of 2° with respect to theecliptic.[2] The asteroid was first observed as1979 SJ6 atCrimea–Nauchnij in September 1979. The body'sobservation arc begins at Palomar with its official discovery observation in 1990.[1]
1990 QB2 has been characterized as a common, stonyS-type asteroid byPan-STARRS' survey and in theSDSS-based taxonomy.[3][11][12]
In November 2005, a first rotationallightcurve of1990 QB2 was obtained fromphotometric observations by Australian amateur astronomerDavid Higgins. Lightcurve analysis gave a well-definedrotation period of 3.5257 hours with a high brightness variation of 0.77magnitude (U=3).[9] In January 2014, observations in the R-band at thePalomar Transient Factory in California gave two concurring periods of 3.523 and 3.53 hours with an amplitude of 0.60 magnitude (U=2/2).[8][10] A high brightness amplitude typically indicates that the body has a non-spherical shape
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,1990 QB2 measures 3.345 kilometers in diameter and its surface has analbedo of 0.250.[5][6] TheCollaborative Asteroid Lightcurve Link adoptsPetr Pravec's revised WISE-result, that is, an albedo of 0.2232 and a diameter of 3.351 kilometers based on anabsolute magnitude of 14.62.[3][7]
Thisminor planet was numbered on 2 February 1999 (M.P.C. 33659).[14] As of 2018, it has not beennamed.[1]
