Pole orientation and triaxial ellipsoid shape of (25143) 1998 SF36, a target asteroid of the MUSES-C* mission

The near-earth asteroid (25143) 1998 SF36 is a target body for the Japanese sample-return MUSES-C mission. We present here its pole orientation and triaxial ellipsoid shape, using light curve data obtained with three telescopes at Kiso, Mitaka, and Pic du Midi. The solution obtained for the pole orientation has ecliptic latitude λ = 320 ± 30° and ecliptic longitude β = —75 ± 12°. The estimated triaxial ellipsoid shape is a/b= 2.1 and b/c= 1.7 assuming m= 0.03, which is the coefficient of the empirical relation between the light curve amplitude and the phase angle for S-type asteroids (Zappalà et al., 1990). We also found m to be related to asteroid surface roughness, using a light curve simulator.