Nuclear parameters of comets 63P/Wild 1 and C/2012 K1 (PANSTARRS)

Abstract

We analyzed R-band magnitudes of the short and long orbital period comets Wild 1 and PANSTARRS. The observations were performed trhough a 0.2-m f/9 refractor telescope equipped with a SBIG ST-10 XME detector from the Olmen Observatory (Belgium), between 2013 and 2014. We estimate apparent nuclear magnitudes of the two comets, using a relationship between the R magnitude and the photometric aperture radius (in arcsec) (see Betzler et at. 2017, AdSpR, 60, 3, 612). Correlating those magnitudes with the heliocentric and geocentric distances and we were able to get the nuclear absolute magnitude Hn0 = 16.3 ± 0.6 and 12.70 ± 0.07 and the activity indices n = 0.5 ± 0.9 and 0.94 ± 0.03. The nuclear radii are 1.5 and 8.7 km. The absolute value of the nuclear radius and activity indices correspond to those expected for comets with short and long orbital periods.