Comet C/2010X1 (Elenin). Unrealized expectations

Abstract

We present the analysis of the photometric and spectroscopic data obtained for comet C/2010 X1 (Elenin) when it was at a distance of 2.92 AU from the Sun. The observations were made at the prime focus of the 6-m BTA telescope with the SCORPIO focal reducer. The magnitude of the comet, measured in the Rc-band with an 9″ aperture radius amounted to 16ṃ8 ± 0ṃ1. The computed dust production rate was estimated to be about 6 kg/s. The cometary coma manifested the emissions in the (0–0) band of the CN molecule violet system, and a number of emission band heads of the C3 molecule. The gas production rate of the molecules is determined using the Haser model and amounts to 1.41 × 1024 and 4.20 × 1023 molecules per second for CN and C3, respectively. The ratio of gas production rates log[Q(C3)/Q(CN)] is equal to −0.85, which is close to the mean value, determined for a significant number of comets. A normalized gradient of the cometary dust reflectivity, calculated for the 4430–6840 A spectral range amounts to 14.3 ± 1.2%.