| Abstract : | Comets, as the most ancient relics of our solar system, offer a wealth of information about the conditions prevailing during its early stages. Indian telescopes were employed to conduct low-resolution spectroscopic analyses on 22 comets, including those from diverse reservoirs and the only interstellar comet 2I/Borisov. Additionally, high-resolution spectroscopic, imaging, and polarimetric observations were carried out on selected comets to investigate these celestial bodies rich in pristine volatile materials.
Notably, the low-resolution spectroscopic analysis of the first interstellar comet confirmed the heterogeneous composition of its nucleus. Simultaneously, photometric, spectroscopic, and polarimetric observations of comet 156P/Russell-LINEAR underscored the significance of employing multiple investigative techniques for comprehensive cometary studies.
Findings from the observations of these 22 comets include insights into the presence of specific molecules, their production rates, column densities, dust-to-gas ratios, Ortho-to-Para ratio of NH2, Green-to-Red doublet ratio of forbidden Oxygen lines, and more. Moreover, the relative molecular abundances, line ratios, and their behavior with respect to heliocentric distances were examined to discern the individual composition of each comet and gain a collective understanding of their variations.
These investigations also explored potential interdependencies among various emission activities, to understand better the photo-chemistry happening within the coma. Finally, the need for an open-access database encompassing all comets observed to date which would serve as a valuable resource for the broader scientific community, helping expand the boundaries of cometary studies has been emphasised. |
