New model for calculation the radius of comet’s nucleus

In this work, a new equation derived to obtain some physical properties like radius and luminosity of comets using distances between the comet, the Earth and the Sun that represent the geocentric distance and heliocentric distance at applying it to a some of comets in two different regions, namely the Kuiper belt and the Oort cloud. This relation gave very good results when compared. From the results, it can form important relation between the radius with luminosity, when the radius increased the luminosity increased too this relation proportional. And the calculation has been made for the phase angle. The relation between luminosity as a function of radius have been found.