Author(s): , , ,
Institution(s): 1. Aryabhatta Research Institute of Observational Sciences, 2. ASSAM UNIVERSITY
We present the polarimetric results and analysis of two comets C/2013 V1 (Boattini) and 290P/Jager at lower phase angles. The observation of comets at lower phase angle is a typical task but the polarimetric study at such phase angle helps to explore the negative branch of polarization-phase curve. The observation of both the comets have been performed in polarimetric mode with the 1.04-metre Sampurnanand telescope of ARIES near Nainital in India on December 4th & 5th, 2013 and on 24th April, 2014. The observations at two different epochs covered both the pre and post perihelion passage of comet C/2013 V1 (Boattini) and 290P/Jager at two phase angles 13o and 27o. The average polarization for Comet C/2013 V1 (Boattini) and Comet 290P/Jager changes from (−1.4% to +2.8%) and (−1.6% to +2.5%) respectively between the two periods of observation. The observed polarization for Comet C/2013 V1 (Boattini) is found to be higher in April as compared to other comets just after two days of its perihelion at 26o phase angle. The cometary coma of both the comets shows significant variation in the brightness profile in both sunward and tailward directions. The prominent variation in the intensity and polarization profile for both the comets at two different epoch suggests that the variation in the physical properties of dust grains present in the coma which include temporal variation in dust concentration, sublimation and fragmentation of large grains during the two periods of observation.