Some Features of Comet Hale-Bopp (According to the Observations of 1995-1998)

"The Great Comet of 1997" was a significant event in cometary physics. Numerous interesting scientific studies are devoted to this comet. Unfortunately, in the Russian scientific literature, there are few publications on investigations of Comet Hale-Bopp. This study is timed to the twentieth anniversary of finishing the main observations of this comet and reminds the readers about some of its unusual and even unique features without pretending to present an exhaustive review of the published materials. In this paper, an attempt is made to estimate the mass of the nucleus of Comet Hale-Bopp and it is supposed that it may be close to the initial mass of Halley's comet which the latter had in the beginning of its evolution. Based on the published images of this comet, the approximate velocity of the gas-dust ejections and the spread of the velocities are calculated. A possible relation between the mass of the total losses and the dynamics of the comet nucleus is considered.