Di Martino is member of the Nysa–Polana complex (405),[4][5] one of the largest asteroid families.[16] Its low albedo (see below) it likely belongs to the Polana family within the larger Nysa–Polana complex. The asteroid orbits the Sun in the inner main-belt at a distance of 2.1–2.7 AU once every 3 years and 8 months (1,339 days; semi-major axis of 2.38 AU). Its orbit has an eccentricity of 0.13 and an inclination of 4° with respect to the ecliptic.[2] The body's observation arc begins with its first observation as A909 BL at Heidelberg Observatory in January 1909, almost 73 years prior to its official discovery observation at Anderson Mesa.[1]
Naming
This minor planet was named after Mario di Martino (born 1947), Italian astronomer and photometrist of lightcurves at the Turin Observatory. The official naming proposed by the discoverer. The citation was prepared by Alain Harris and published by the Minor Planet Center on 14 April 1987 (M.P.C. 11749).[17]
In 2016, a modeled lightcurve gave a concurring sidereal period of 5.44517 hours using photometric data from a large international collaboration of astronomers. The study also determined two spin axes of (53.0°, −70.0°) and (231.0°, −75.0°) in ecliptic coordinates (λ, β).[15]
Diameter and albedo
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Di Martino measures between 11.267 and 15.60 kilometers in diameter and its surface has an albedo between 0.05 and 0.0925.[6][7][8][9][10][11] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0540 and a diameter of 13.72 kilometers based on an absolute magnitude of 13.1.[3]
^ abcdNugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117.
^ abcdMasiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Nugent, C.; et al. (November 2012). "Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids". The Astrophysical Journal Letters. 759 (1): 5. arXiv:1209.5794. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8.
^ abBirlan, M.; Barucci, M. A.; Angeli, C. A.; Doressoundiram, A.; De Sanctis, M. C. (June 1996). "Rotational properties of asteroids: CCD observations of nine small asteroids". Planetary and Space Science. 44 (6): 555–558. Bibcode:1996P&SS...44..555B. doi:10.1016/0032-0633(96)00019-0.
^ abcdHanus, J.; Durech, J.; Oszkiewicz, D. A.; Behrend, R.; Carry, B.; Delbo, M.; et al. (February 2016). "New and updated convex shape models of asteroids based on optical data from a large collaboration network". Astronomy and Astrophysics. 586: 24. arXiv:1510.07422. Bibcode:2016A&A...586A.108H. doi:10.1051/0004-6361/201527441.