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Yunnan Observatory's Catastrophe Double Star Candidate Identity Card Identification Research Progress
[ Instrument R & D of Instrument Network ] On April 15, The Astrophysical Journal, an international astrophysics journal, published a research result of Dai Zhibin and others from the Double Star and Variable Star Research Group of Yunnan Observatory, Chinese Academy of Sciences. They not only recognized the true position coordinates of Gemini KZ, but also realized the analysis and research of the complete accretion physical process.
For a long time, the orbital vacancy of catastrophic binaries has been regarded as "accumulated white dwarf forbidden zone" by its evolution theory, making catastrophic binaries in vacancies generally regarded as a kind of "special existence". However, because most of them are very weak, there is insufficient follow-up certification observation. In 2014, Kepler-II measured the KZ Gemini, a candidate for a catastrophic binary star in an orbital vacancy, for three consecutive months, and only found that the conventional ellipsoidal photovariation is seriously inconsistent with the "shock" feature that is considered empirically.
Dai Zhibin and others used Xinglong Observatory (XLO), multiple meter-level telescope equipment from APO and MDM Observatory in the United States to conduct long-term ground-follow-up observation data accumulation and recertification research on the identity of the violent binary star on KZ Gemini, and found many public There are significant differences between the position coordinates given by the database (SDSS, SIMBAD, Kepler, AAVSO) and the catastrophe binary star table. The wrong coordinates and identity have puzzled people for more than half a century-no effective observation data has been published so far.
Due to the complicated accretion process and the high luminosity ratio between sub-stars, the catastrophic binary system overwhelms the absorption line of the main sequence companion star, and usually appears as a single-spectral binary star. Dai Zhibin and others used cross-correlation spectroscopy technology to successfully extract the spectral lines of companion stars, to achieve bispectral line-of-sight velocity analysis, and to improve the accuracy of the orbit period to the order of milliseconds, which is two orders of magnitude higher than the analysis results of Kepler space satellite data.
Based on this and combined with multi-band photometry data, they have successfully provided a complete picture of the white dwarf disk accretion physics, which provides high-precision basic physical parameters for the long-term accretion evolution of subsequent studies.
The research results have been supported by key projects of the National Natural Science Foundation of China and projects of Yunnan Basic Applied Research.