Observations of the inner coma of C/1995O1 (Hale–Bopp)—gas and dust production

Abstract

Hale–Bopp (C/1995 O1) was the most productive recent comet observed in terms of gas and dust output. Since its discovery in 1995 at a distance of 7.14 AU from the Sun, the comet has been well observed, revealing the dynamics of a rare and large comet. Hale–Bopp showed strong emissions of the principle cometary gases CN, C 3, and C 2, as well as an abundance of dust. The production rates of these gases were found to be 1.45 × 10 28 , 1.71 × 10 28 , and 3.52 × 10 28 molecules s - 1 , respectively, with dust production, in terms of A f ρ , 1.36 × 10 6 cm , as measured in the green continuum (5260 Å). The observations for this paper are presented in two groups spanning 10 days each, one group centered near 32 days prior to and the other 21 days after perihelion. The averages of dust and gas production rates show a slightly higher value for each prior to perihelion than after perihelion, consistent with a possible peak in production a few weeks prior to perihelion passage.