Total Gas Concentration in Atmospheres of the Short-Period Comets and Impulsive Forces upon Their Nuclei
The mass4oss rates are calculated for 23 short-period comets with known systematic deviations from the gravitational law in their motion. The C2 amount in the atmospheres of the comets, calculated from photo- metric data, is compared with the total abundance of gases (mostly nonluminous), derived from dynamical data. The results show that C2 represents not more than 0.1 per mille of the total gas concentration, on an average. It is suspected that the ratio between the total and C2 densities might tend to increase secularly. It is concluded that the vast amounts of gases liberated from the nucleus each revolution (at least 10 - 10i g) are able to explain the whole dynamical effect observed in the short-period comets and that their nuclei should be 10' -102 g in mass.