The activity of 119 comets

Abstract

ABSTRACT This study examines photometric data from 119 comets observed between 2011 and 2020 at the Olmen Observatory in Balen, Belgium, using R- and G-band filters. Applying the q-exponential distribution from Tsallis’ non-extensive mechanics, we find that our sample of short-period (SP) and long-period (LP) comets is complete for objects with an absolute magnitude of H0 ≤ 11.2 and ≤8.7, respectively. These magnitude constraints were used to perform a statistical analysis of the physical parameters describing these populations. LP comets generally have brighter absolute magnitudes and higher activity (median ×  15.4) compared to SP comets. The secular light curves of these comets are symmetric about perihelion. Cometary activity was divided into four categories (‘unusual’, ‘typical’, ‘moderate’, and ‘strong’) based on the Afρ(0) parameter at perihelion, with about 72.7 and 53.6  per cent of the SP and LP comets falling into the ‘typical’ classification. The distribution of peak magnitudes ΔM for outbursts is similar for SP and LP comets, with a median value of −1.0 and a range of −0.2 to −2.90 mag. On average, there are 0.6 and 1.0 outbursts per comet for comets SP and LP, respectively. This result suggests that these events are somewhat more frequent for the LP comets. There is no evidence of periodicity in the frequency of outbursts based on our data. The peak magnitude ΔM of an outburst does not correlate with Afρ(0).