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Post Info TOPIC: KIC 9832227


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RE: KIC 9832227
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Title: Prediction of a red nova outburst in KIC 9832227
Author: Lawrence A. Molnar, Daniel M. Van Noord, Karen Kinemuchi, Jason P. Smolinski, Cara E. Alexander, Evan M. Cook, Byoungchan Jang, Henry A. Kobulnicky, Christopher J. Spedden, Steven D. Steenwyk

We present the first identification of a candidate precursor for an imminent red nova. Our prediction is based on the example of the precursor to the red nova V1309 Sco, which was retrospectively found to be a contact binary with an exponentially decreasing period. We explore the use of this distinctive timing signature to identify precursors, developing the observational and analysis steps needed. We estimate that our Galaxy has roughly 1-10 observable precursors. Specifically, we lay out the observational case for KIC 9832227, which we identified as a tentative candidate two years ago (Molnar et al. 2015, AAS Meeting Abstracts 415.05). Orbital timing over the past two years has followed the tentative exponential fit. As of late 2015, the period time derivative went beyond the range found in other systems (dP/dt < 1x10^{-8}), a necessary criterion for a serious candidate. We estimate time of merger is the year 2022.2(7). Double absorption line spectra confirm directly the 0.458 d light curve period is a contact binary system and yield a mass ratio m_B/m_A = 0.228(3). Closer analysis of the Kepler timing data shows evidence of a component C with orbital period P_C = 590(8) days and m_C x sin i_C = 0.11 solar masses. An alternative interpretation of the long term timing trend, light travel time delay due to orbit around a distant component D, is ruled out by the spectroscopic data for any nondegenerate star. Additional measurements are needed to test further the merging hypothesis and to utilize fully this fortuitous opportunity.

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Posts: 131433
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Title: Prediction of a Red Nova Outburst in KIC 9832227
Authors: Lawrence A. Molnar, Daniel M. Van Noord, Karen Kinemuchi, Jason P. Smolinski, Cara E. Alexander, Evan M. Cook, Byoungchan Jang, Henry A. Kobulnicky, Christopher J. Spedden, and Steven D. Steenwyk

We present the first identification of a candidate precursor for an imminent red nova. Our prediction is based on the example of the precursor to the red nova V1309 Sco, which was retrospectively found to be a contact binary with an exponentially decreasing period. We explore the use of this distinctive timing signature to identify precursors, developing the observational and analysis steps needed. We estimate that our Galaxy has roughly 1-10 observable precursors. Specifically, we lay out the observational case for KIC 9832227, which we identified as a tentative candidate two years ago (Molnar et al. 2015, AAS Meeting Abstracts 415.05). Orbital timing over the past two years has followed the tentative exponential fit. As of late 2015, the period time derivative went beyond the range found in other systems (P < | 1 x 10^-8 |), a necessary criterion for a serious candidate. We estimate time of merger is the year 2022.2 ± 0.6. Double absorption line spectra confirm directly the 0.458 d light curve period is a contact binary system and yield a mass ratio mB/mA = 0.23. Closer analysis of the Kepler timing data shows evidence of a component C with orbital period PC = 590 ± 8 days and mC sin iC = 0.11 solar masses. An alternative interpretation of the long term timing trend, light travel time delay due to orbit around a distant component D, is ruled out by the spectroscopic data for any nondegenerate star. Additional measurements are needed to test further the merging hypothesis and to utilize fully this fortuitous opportunity.

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Double star may light up the sky as rare red nova in six years

A dim binary star is behaving exactly as expected if it is about to explode as a "red nova". If that happens, in 2022 or so it could shine as brightly as the North Star.
Dozens of ordinary novae - the temporary flare-ups of white dwarf stars stealing gas from their companion star - explode in our galaxy every year. These novae turn blue.
In recent years, however, astronomers have discovered a rare type of nova that turns red instead. At peak brightness, many red novae rival the most luminous stars in the galaxy.

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