Balam is a member of the Flora family, a very large group of stony asteroids in the inner main-belt. It orbits the Sun in the inner main-belt at a distance of 2.0–2.5 AU once every 3 years and 4 months (1,222 days). Its orbit has an eccentricity of 0.11 and an inclination of 5° with respect to the ecliptic.[1]
It is named after the Canadian astronomer David Balam, principal observer at Victoria's Climenhaga Observatory in British Columbia.[2] The approved naming citation was published by the Minor Planet Center on 31 May 1988 (M.P.C. 13178).[16]
The S-type asteroid has an albedo of 0.16.[14] The body's rotation around its axis has been measured several times by different lightcurve observations with a concurring period of 2.8 hours.[11][12][13][a]
On 13 February 2002, the discovery of a minor-planet moon, provisionally designated S/2002 (3749) 1, was announced by a team of researchers from SwRI, UA, JPL and OSUG, using the Gemini North TelescopeonMauna Kea in Hawaii.[17] It has an estimated diameter of 1.84 kilometers. It orbits 289±13 km away in 61±10 days, with a high orbital eccentricity of ~ 0.9. The distant and highly eccentric orbit of S/2002 (3749) 1 suggests that it was likely captured by Balam.[10]
Being such a small primary body in the inner main belt with a separation of over 100 primary radii, S/2002 (3749) 1 is the most loosely bound binary known.[18] Balam has a Hill sphere with a radius of about 1,500 kilometers.[10]
In March 2008, Franck Marchis discovered another companion, provisionally designated S/2008 (3749) 1, making Balamatrinary asteroid.[19][20] The inner satellite has a derived diameter of 1.66 kilometer, based on diameter-ratio of 0.42±0.03 with its primary.[4]
Balam also forms an asteroid pair with (312497) 2009 BR60.[5] Asteroid pairs are on highly similar heliocentric orbits. At some point in the past, the pair of asteroids became gravitationally unbound due to rotational fission induced by the YORP-effect or from a collisional breakup of the parent body. After the discovery of Balam's two satellites by Bill Merline (inner moon) and Franck Marchis (outer moon) in 2002 and 2008, respectively, Czech physicist David Vokrouhlický identified the unbound secondary in 2009. Based on backward orbit integrations, it is thought that Balam and 2009 BR60 form a secured asteroid pair that became separated approximately 400,000 years ago.[5]
^ abcPravec-2012web, rotation period of 2.80478±0.00005 with an amplitude in brightness variation of 0.1 magnitude. Summary figures for (3749) Balam at Lightcurve Database
^ abcMarchis, F.; Enriquez, J. E.; Emery, J. P.; Mueller, M.; Baek, M.; Pollock, J.; et al. (November 2012). "Multiple asteroid systems: Dimensions and thermal properties from Spitzer Space Telescope and ground-based observations". Icarus. 221 (2): 1130–1161. arXiv:1604.05384. Bibcode:2012Icar..221.1130M. doi:10.1016/j.icarus.2012.09.013. S2CID161887.
^Merline, W. J.; Close, L. M.; Siegler, N.; Dumas, C.; Chapman, C. R.; Rigaut, F.; et al. (September 2002). "Discovery of a Loosely-bound Companion to Main-belt Asteroid (3749) Balam". American Astronomical Society. 34: 835. Bibcode:2002DPS....34.0201M.
^Franck Marchis – Principal Investigator, SETI Institute, UC Berkeley. "Franck Marchis Web Page". Department of Astronomy (University of California at Berkeley). Archived from the original on 10 November 2007. Retrieved 27 October 2009.{{cite web}}: CS1 maint: multiple names: authors list (link)
