High nitrogen and carbon isotopic ratios in the interstellar comet 3I/ATLASOPEN ACCESS
C. Opitom, J. Manfroid, D. Hutsemékers, E. Jehin, M. M. Knight, K. Aravind, L. Ferellec, D. Bodewits, V. V. Guzmán, M. Cordiner, R. C. Dorsey, F. La Forgia, M. Lippi, B. P. Murphy, C. Snodgrass, M. Bannister
Submitted for publication to Nature
“Interstellar objects provide a unique opportunity to further our understanding of the planetary formation process by studying in detail material formed around another star. Their ices contain precious clues about the environment and conditions prevailing in their home system. As fractionation processes can be sensitive to the temperature and radiation environment, isotopic ratios are powerful tracers of the origin and evolution of different species. While isotopic ratios have been measured in solar system comets, previously detected interstellar objects have been too faint to measure isotopic ratios. Here we report the measurement of two ratios in 3I/ATLAS from observations of the CN molecule: 12C/13C and 14N/15N. We report 12C/13C = 147+87−40 and 14N/15N = 343+454−124 . The 14N/15N is higher than the value of ∼ 150 usually measured for solar system comets, close to the values measured in the interstellar medium, pre-stellar phases or the outside of protoplanetary discs. The 12C/13C is marginally higher
than the values usually measured for solar system comets and in the interstellar medium. These measurements could indicate an origin of 3I in the outer disc around an older low-metallicity star”
