Behavioral Characteristics and CO+CO 2 Production Rates of Halley-type Comets Observed by NEOWISE

Abstract

From the entire data set of comets observed by NEOWISE , we have analyzed 11 different Halley-type Comets (HTCs) for dust production rates, CO+CO 2 production rates, and nucleus sizes. Incorporating HTCs from previous studies and multiple comet visits, we have a total of 21 stacked visits, 13 of which are active and 8 for which we calculated upper limits of production. We determined the nucleus sizes of 27P, P/2006 HR30, P/2012 NJ, and C/2016 S1. Furthermore, we analyzed the relationships between dust production and heliocentric distance, and gas production and heliocentric distance. We concluded that for this population of HTCs, ranging in heliocentric distance from 1.21 to 2.66 au, there was no significant correlation between dust production and heliocentric distance, nor between gas production and heliocentric distance.