Comet P/Gehrels 3: spectroscopic observations and nucleus models

In the framework of an observational campaign for increasing the knowledge on the relationship between cometary nuclei and asteroids, we performed spectroscopic observations of P/Gehrels 3. The Jupiter family comet P/Gehrels 3 moves on a particular orbit, with a very high Tisserand invariant with respect to Jupiter, that makes the encounters with the planet very effective. This implies that the comet spends part of its life as a temporary satellite of Jupiter, on an orbit that shows similarity with those of Trojans. This comet has been observed when it was far from the Sun, with the aim to acquire data on the nucleus status. In order to study from a theoretical point of view the possible status and evolution of a body on this orbit we have developed different nucleus models using a numerical code for the thermal evolution of the nucleus.