A research project to probe close binary stars was accepted on May 8 by an evaluation panel under the sponsorship of the CAS Kunming Branch in southwest China's Yunnan Province.
A sky-watching project, under the title of An Observational Study on Special Physical Processes Taking Place in Close Binary Starts, was initiated and completed by a research team with Prof. Qian Shengbang as its head at Yunnan Observatory, a research affiliate of the National Astronomical Observatories of CAS.
Binary stars are a unique kind of celestial bodies in the stellar world, featuring a structural duality by always presenting themselves in pairs. There is a series of intensive and complicated event of interaction between the two component stars in each of them, giving rise to many special physical processes. Astrophysicists believe the latter hold the clues for demystifying several unsolved cosmic puzzles of vital importance.
Analytic studies on orbiting period variations of binary stars systematically carried out by the research team lead to the following results:
1. Several sudden and irregular changes superimposed on the background of a long-time decrease in the orbital periods of an AF-typed Algol (Algo-type binary stars) are discovered. The research team elucidates this phenomenon by claiming that this is caused by variable angular moment losses in these binary systems;
2. The orbiting period of some Algol-type binary stars with exceedingly low mass ratios were found to be in a long-time and rapid increase. This implies, according to the research team, that there exists a fast mass exchange from the less massive star to more massive one;
3. A group of AF-type near-contact binary stars with their orbital periods in a long-time reduction was brought to light. In addition, the reducing rate presents a strong interdependence with the orbital periods themselves;
4. Three of the Algol-typed binary stars were discovered to have a long-time and rapid increase in their orbital periods added with several eruptive changes. Unlike other recently discovered counterparts, the latter do not display an alternative pattern in their variations;
5. Periodic changes in the orbital periods of some active binaries are spotted and the scientists of the research team believe they resulted from the ups and downs of subsurface magnetic field of the active component star;
6. The orbital period change of overcontact of binary stars was discovered to correlate with the binary system's mass ratio and the mass of the primary component star.