2606 Odessa, provisional designation 1976 GX2, is a background asteroid from the central regions of the asteroid belt, approximately 16 kilometers (10 miles) in diameter. It was discovered on 1 April 1976, by Soviet–Russian astronomer Nikolai Chernykh at the Crimean Astrophysical Observatory in Nauchnij, on the Crimean peninsula.[1] The presumably metallic X- or M-type asteroid has an elongated shape and a rotation period of 8.24 hours.[7] It was named for the Ukrainian city of Odesa.[2]
In 2008, two rotational lightcurves of Odessa were obtained from photometric observations at the Hunters Hill and Oakley Southern Sky observatories in Australia. Lightcurve analysis gave a well-defined rotation period of 8.2426 and 8.244 hours with a brightness amplitude of 0.80 and 0.72 magnitude, respectively, indicative for a non-spherical shape (U=3/3).[8][9]
In 2016, a modeled lightcurve gave a concurring sidereal period of 8.2444 hours using data from the Uppsala Asteroid Photometric Catalogue, the Palomar Transient Factory survey, and individual observers (such as above), as well as sparse-in-time photometry from the NOFS, the Catalina Sky Survey, and the La Palma surveys (950). The study also determined two spin axes of (25.0°, −81.0°) and (283.0°, −88.0°) in ecliptic coordinates (λ, β).[10]
Diameter and albedo
According to the survey carried out by the NEOWISE mission of NASA's WISE telescope, Odessa measures 15.91 kilometers in diameter and its surface has an albedo of 0.175,[5][6] while the Collaborative Asteroid Lightcurve Link assumes a carbonaceous standard albedo of 0.057 and consequently calculates a larger diameter of 25.44 kilometers based on an absolute magnitude of 11.7.[7]
^ abHanuš, J.; Ďurech, J.; Brož, M.; Marciniak, A.; Warner, B. D.; Pilcher, F.; et al. (March 2013). "Asteroids' physical models from combined dense and sparse photometry and scaling of the YORP effect by the observed obliquity distribution". Astronomy and Astrophysics. 551: A67. arXiv:1301.6943. Bibcode:2013A&A...551A..67H. doi:10.1051/0004-6361/201220701. ISSN0004-6361.