Optical Properties of (162173) 1999 JU3: In Preparation for the JAXA Hayabusa 2 Sample Return Mission

摘要: We investigated the magnitude-phase relation of (162173) 1999 JU3, a target asteroid for JAXA Hayabusa 2 sample return mission. initially employed International Astronomical Union's H-G formalism but found that it fits less well using single set parameters. To improve inadequate fit, we two photometric functions: Shevchenko and Hapke functions. With function, exhibits linear behavior in wide phase angle range (α = 5°-75°) shows weak nonlinear opposition brightening at α < 5°, providing more reliable absolute magnitude H {sub V} 19.25 ± 0.03. The slope (0.039 0.001 mag deg{sup –1}) effect amplitude (parameterized by ratio intensity 0.°3 to I(0.°3)/I(5°) 1.31 0.05) are consistent with those typical C-type asteroids. also attempted determine parameters model, which applicable constructing surface reflectance map onboard cameras. Although could not constrain full parameters, obtained possible values, w 0.041, g –0.38, B 0} 1.43, h =more » 0.050, assuming roughness parameter θ-bar 20°. By combining our study thermal model asteroid, geometric albedo p v} 0.047 0.003, integral q 0.32 0.03, Bond A B} 0.014 0.002, commensurate values common asteroids.« less