Chemical Evolution of Milkey-way Galaxy and Origin of Solar System from Nitrogen Isotopic Ratios in Classical Novae

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K13466
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Astronomy
• Research Institution: Kyoto Sangyo University
• Principal Investigator: KAWAKITA Hideyo 京都産業大学, 理学部, 教授 (70356129)
• Co-Investigator(Kenkyū-buntansha): 新井 彰 京都産業大学, 神山天文台, 研究員 (30582457)
• Co-Investigator(Renkei-kenkyūsha): WATANABE Jun-ichi 国立天文台, 天文情報センター, 教授 (50201190)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 古典新星 / 分子生成 / 同位体比 / 熱核暴走反応

Outline of Final Research Achievements

For a "very slow nova", a photospheric temperature of the nova decreased toward the visual brightness maximum after its outburst, then reached low temperatures suitable for molecular formation like C2 and CN. We have detected C2 and CN molecules simultaneously for the first time in V2676 Oph and derive the isotopic ratios of carbon and nitrogen. These ratios are consistent with the theoretical predictions for the thermo-nuclear runaway reactions on a relatively massive white dwarf. However, the very slowly evolution of its light curve indicates that the mass of white dwarf is smaller based on the nova-wind theory for the optical light curve. There is a discrepancy between those nova models.

Free Research Field

天文学