On the accuracy of indirect methods for estimation of asteroid sizes

1Morozhenko, OV, 1Vidmachenko, AP
1Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine
Section: Dynamics and Physics of Solar System Bodies
Language: Russian
Abstract: 

Using data on the maximum value of negative polarization degree is shown to be the least reliable in estimating asteroid albedos. To improve the reliability of the method based on the information relative to the positive polarization branch slope, the approximation coefficient values are bound to be chosen for a particular type of asteroids. The same situation is in the case of the thermal method where each type needs a corresponding value of the phase integral q. In addition, the accuracy of both methods increases if a corresponding type of characteristic phase dependence of brightness is used for the transition from to , including the opposition effect. Our simulation within the framework of the Irwin — Yanovitskij modification of the Hapke shadow model shows that the values of the phase coefficient β (10° ≤ α ≤ 20°) and q lie within the limits 0.016—0.030 and 0.6—1.0 (E-type of asteroids), 0.026—0.033 and 0.42—0.52 (M-, S-types), 0.031—0.039 and 0.42—0.52 (C-type), respectively.

Keywords: asteroid, method