I Congreso de Postgrado fcfm: ingeniería, ciencias e innovación

28 Santiago, 10 al 12 de agosto, 2022 A S T RONOM Í A 01 UNDERSTANDING THE EFFECT OF PHYSICAL PROPERTIES ON VOLATILE PRODUCTION RATES OF COMETS Amrita Singh¹* , Dr. Kinsuk Acharyya² ¹Department of Astro omy, University of C ile, S ntiago, Chile. ²Physical Research Laboratory, Ahmedabad, Gujrat, India. *Email: amrita@das.uchile.cl ABSTRACT Comets are frozen cosmic leftovers of dust rocks, grains, and volatile ices. They are chemically inert and thus retain the pristine and critical information about chemical compositions and the physical properties at the time of formation of planetary system from the solar nebula, 4.6 billion years ago. Study of production rates of comets allows us to understand the formation of star-planetary systems. Production rates (Q rates, hereafter) of com- ets decrease significantly at R> 3-4 AU, only hyper volatiles like CO, etc. and dust activity are seen occasionally beyond this heliocentric distance, so it is interesting to see the effects of solar activity on comets, with vary- ing heliocentric distances. Previously published properties of short and long period comets were collected and complemented by new results in this work. A systematic analysis of water Q rates of short period Comets 2P/ Encke (Encke, shortest period comet, detailed analysis), 21P/Giacobini-zinner (21P/G-Z), 41P/Tuttle-Giacobi- ni-Kresak (41P/T-G-K), 96P/Macholz, and 67P/Churyumov-Gerasimenko (67P/C-G) and long period comets O1 Hale-Bopp, OG108 LONEOS and C/1996 B2 (Hyakutake) are presented in this paper. Water Q rates of 2P/Encke is investigated in detail, using 60 years of data. Water Q rates at various heliocentric distances and at 1 AU are also calculated for various apparitions of the comets. We have plotted the derived observational data to examine the asymmetries about perihelion and to analyze trends with heliocentric distances and years of apparitions. Effects of albedo, size, and solar activity on water production rates of these comets are carefully analyzed by over plotting solar cycle and water Q rates calculated at 1 AU against years of apparitions. We have tried to find a correlation between these by calculating Pearson coefficient for pre- and post- perihelion heliocentric distances. Correlation coefficient calculated for short period comets varies independently while due to insufficient amount of data for long period comets, it was not possible to calculate it. We are also investigating the correlation of water Q rates with perihelion distance, although the variations in perihelion distance is very small, but showing observable effects on the Q rates. Inter-comparison of water production rates and correlations with sunspots of various comets appears to give a meaningful conclusion, more constraints needed to include for further study on the same. We do not observe any correlation in Q rates with different year of apparitions for these comets. ACKNOWLEDGEMENTS AS is grateful to Prof. Patricio Rojo for his valuable comments and Dr. Kinsuk Acharyya for guiding throughout the thesis. REFERENCES [1] Sanzovo, G. De Almeida, Amaury Misra, Mon. Not. R. Astron. Soc. 326, 852-868 (2001), 8, 2001. [2] Combi MR et. Al. doi: 10.1016/j.icarus.2018.08.031. 617, 2018 Sep 3. [3] Krishnaswamy, Physics of comets, Edition 3rd, Chapter 1, 2010.