1990 QB2 is member of the Nysa family (405),[4] located in the Nysa–Polana complex. It is named after 44 Nysa and one of the largest families in the main belt.[13]: 23
The asteroid orbits the Sun in the inner 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 an eccentricity of 0.22 and an inclination of 2° with respect to the ecliptic.[2] The asteroid was first observed as 1979 SJ6 at Crimea–Nauchnij in September 1979. The body's observation arc begins at Palomar with its official discovery observation in 1990.[1]
In November 2005, a first rotational lightcurve of 1990 QB2 was obtained from photometric observations by Australian amateur astronomer David Higgins. Lightcurve analysis gave a well-defined rotation period of 3.5257 hours with a high brightness variation of 0.77 magnitude (U=3).[9] In January 2014, observations in the R-band at the Palomar 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
Diameter and albedo
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, 1990 QB2 measures 3.345 kilometers in diameter and its surface has an albedo of 0.250.[5][6] The Collaborative Asteroid Lightcurve Link adopts Petr Pravec's revised WISE-result, that is, an albedo of 0.2232 and a diameter of 3.351 kilometers based on an absolute magnitude of 14.62.[3][7]
^ abcdPravec, Petr; Harris, Alan W.; Kusnirák, Peter; Galád, Adrián; Hornoch, Kamil (September 2012). "Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations". Icarus. 221 (1): 365–387. Bibcode:2012Icar..221..365P. doi:10.1016/j.icarus.2012.07.026.
^ abcWaszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. arXiv:1504.04041. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. S2CID8342929.
^ abHiggins, David; Pravec, Petr; Kusnirak, Peter; Reddy, Vishnu; Dyvig, Ron (September 2006). "Asteroid lightcurve analysis at Hunters Hill Observatory and collaborating stations - summer 2005/6". The Minor Planet Bulletin. 33 (3): 64–66. Bibcode:2006MPBu...33...64H. ISSN1052-8091.