Activity of the first interstellar comet 2I/Borisov around perihelion: Results from Indian observatories

التفاصيل البيبلوغرافية
العنوان: Activity of the first interstellar comet 2I/Borisov around perihelion: Results from Indian observatories
المؤلفون: Krishnakumar, Aravind, Ganesh, Shashikiran, Venkataramani, Kumar, Sahu, Devendra, Angchuk, Dorje, Sivarani, Thirupathi, Unni, Athira
سنة النشر: 2021
المجموعة: Astrophysics
مصطلحات موضوعية: Astrophysics - Earth and Planetary Astrophysics
الوصف: Comet 2I/Borisov is the first true interstellar comet discovered. Here we present results from observational programs at two Indian observatories, 2 m Himalayan Chandra Telescope at the Indian Astronomical Observatory, Hanle (HCT) and 1.2 m telescope at the Mount Abu Infrared Observatory (MIRO). Two epochs of imaging and spectroscopy were carried out at the HCT and three epochs of imaging at MIRO. We found CN to be the dominant molecular emission on both epochs, 31/11/2019 and 22/12/2019, at distances of r$_H$ = 2.013 and 2.031 AU respectively. The comet was inferred to be relatively depleted in Carbon bearing molecules on the basis of low $C_2$ and $C_3$ abundances. We find the production rate ratio, Q($C_2$)/Q(CN) = 0.54 $\pm$ 0.18, pre-perihelion and Q($C_2$)/Q(CN) = 0.34 $\pm$ 0.12 post-perihelion. This classifies the comet as being moderately depleted in carbon chain molecules. Using the results from spectroscopic observations, we believe the comet to have a chemically heterogeneous surface having variation in abundance of carbon chain molecules. From imaging observations we infer a dust-to-gas ratio similar to carbon chain depleted comets of the Solar system. We also compute the nucleus size to be in the range $0.18\leq r \leq 3.1$ Km. Our observations show that 2I/Borisov's behaviour is analogous to that of the Solar system comets.
Comment: Accepted for publication in MNRAS, 10 pages, 8 figures
نوع الوثيقة: Working Paper
DOI: 10.1093/mnras/stab084
URL الوصول: http://arxiv.org/abs/2101.02752
رقم الأكسشن: edsarx.2101.02752
قاعدة البيانات: arXiv