In August 1995, a first period of 7.114 hours was determined by Stefano Mottola (U=n/a).[13] In March 2004, French amateur astronomer René Roy obtained a period of 7.11±0.01 hours with an amplitude of 0.28±0.01 magnitude from three nights of observations (U=3),[14] while Robert K. Buchheim determined a period of 7.106±0.005 hours and an amplitude of 0.28±0.02 magnitude observing Benda over 10 nights at the Altimira Observatory (G76) in November 2007 (U=3).[15] In September 2018, a collaboration of the Italian Amateur Astronomers Union reported a period of 7.105±0.001 hours with a brightness variation of 0.25±0.03 magnitude (U=3–).[16]
Diameter and albedo
According to the surveys carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), the Infrared Astronomical Satellite IRAS, and the Japanese Akari satellite, Benda measures (65.917±0.746), (70.82±2.9) and (73.28±1.57) kilometers in diameter and its surface has an albedo of (0.054±0.010), (0.0464±0.004) and (0.044±0.002), respectively.[7][8][9] The Collaborative Asteroid Lightcurve Link derives a low albedo of 0.0387 and a diameter of 70.71 kilometers based on an absolute magnitude of 9.9.[13]
Alternative mean-diameters published by the WISE team include (64.45±17.46 km), (67.318±0.267 km),[11] (70.085±0.269 km), (70.65±16.79 km) and (71.722±22.052 km) with a corresponding albedo of (0.05±0.04), (0.051±0.005), (0.0474±0.0092), (0.04±0.02) and (0.037±0.020).[5][13] Two asteroid occultations on 4 April 2009 and on 3 September 2013, gave a best-fit ellipse dimension of (70.0 km × 70.0 km) and (73.0 km × 73.0 km), respectively, each with a low quality rating of 1.[5] These timed observations are taken when the asteroid passes in front of a distant star.[5]
Notes
^ abLightcurve plot of (734) Benda, by Robert Stephens at the Center for Solar System Studies (U81) (2013). Rotation period 7.110±0.003 hours with a brightness amplitude of 0.32 mag. Quality code is 3. Summary figures at the LCDB and CS3 websites.
^ abcdUsui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. (online, AcuA catalog p. 153)
^ abMasiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R.; et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal. 791 (2): 11. arXiv:1406.6645. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121.