| In the course of our lightcurve survey of the Hungaria group, one certain and one probable binary system have been discovered. The observations of (5905) Johnson during April-May 2005 showed a primary rotation lightcurve component with superposed total mutual events, revealing parameters Pprim = 3.7824 +/- 0.0002 hr, Aprim = 0.11 mag, Porb = 21.785 +/- 0.0005 hr, Ds/Dp = 0.40 +/- 0.04, and Dp ~ 5 km. The observations of (9069) Hovland during October-December 2004 showed an additive two-period lightcurve that strongly suggests a binary character for the asteroid as well; the estimated parameters are Pprim = 4.2175 +/- 0.0001 hr, Aprim = 0.09 mag, Psec = 30.33 +/- 0.01 hr, Asec = 0.09 mag, Ds/Dp >~0.3, Dp ~ 3 km. The observed characteristics of the two binaries are similar to those of the two binary Vestoids found by Ryan et al. (2004, Planet. Space Sci. 52, 1093; Bull. Amer. Astron. Society 36, 1181; W.H. Ryan, personal communication), suggesting similar formation and evolution mechanisms for binaries in both families. A comparison with binary NEAs (Pravec and Harris, this conference) suggests that the population of small asynchronous binaries extends from the range of terrestrial planets to the inner main belt with characteristics somewhat dependent on the heliocentric orbits, extending to larger sizes and longer primary periods at larger perihelion distances.
The work at Ondøejov has been supported by the Grant Agency of the Czech Republic, Grant 205/05/0604. The work at Modra has been supported by the Slovak Grant Agency for Science VEGA, Grant 1/0204/03.
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