A NEW CALIBRATION OF THE POLARIMETRIC ALBEDO SCALE OF ASTEROIDS

The constants of the empirical dependences, used for defining asteroid albedos from polarimetric observations, were determined almost 20 yea rs ago. Since then, asteroid albedos have been derived from ground-bas ed radiometric observations, IRAS data, and observations of stellar oc cultations by asteroids. Using all these data and also newly available polarimetric observations of asteroids, we have obtained new values o f the constants of the dependences, which we recommend to be used to d efine asteroid albedos by the polarimetric method. They are log P-nu = -0.98 log h - 1.73 log P-nu = -1.22 log P-min -0.92. The measured val ues of the negative polarization P-min, the polarimetric slope h, and new values of polarimetric albedo p(nu) of 127 asteroids are presented in an accompanying table. (C) 1996 Academic Press Inc.