Biography:

In the past Ya-fang Hong has collaborated on articles with Ya-Fang Hong. One of their most recent publications is The Demarcation Point from E-AGB Stars to TP-AGB Stars in HR Diagram for Medium-mass Stars☆. Which was published in journal Chinese Astronomy and Astrophysics.

More information about Ya-fang Hong research including statistics on their citations can be found on their Copernicus Academic profile page.

Ya-fang Hong's Articles: (2)

The Demarcation Point from E-AGB Stars to TP-AGB Stars in HR Diagram for Medium-mass Stars☆

AbstractVia a study of the evolutionary tracks of 3∼10 M stars on the Hertzsprung-Russell diagram, the variations of the energy, density, temperature at the peak of helium-shell burning, ratio of surface luminosity of helium shell to stellar surface luminosity as well as the stellar radius are analyzed. Then the demarcation point of medium-mass stars in the evolution from early AGB stars to thermally pulsing AGB stars on the HR diagram is determined, and for 119 carbon stars our analysis agrees rather well with observation. At the same time the following is suggested. After arriving at this demarcation point in stellar evolution, in the formula of the loss of stellar wind material it is probably needed to introduce a quantity which is not concerned with the surface luminosity, but it dominates the formation of super stellar wind. On this basis and via the analysis of the structure and evolution of 5 M stars as well as the rate of mass loss of stellar wind, it is found that the effect of turbulent pressure on the mass loss of stellar wind in the stage of thermally pulsing AGB stars is rather great, hence the turbulent pressure of thermally pulsing AGB stars cannot be overlooked. Furthermore, the physical factors which possibly affect the matter loss of the stellar winds of thermally pulsing AGB stars are suggested.

Mechanism of Mass Loss of Stellar Wind for Medium-mass Stars☆

AbstractAlong with the considerations of the effect of constraint of gravitation on the matter loss of stellar wind and the disturbances of the radiation pressure and turbulent pressure on it, by introducing the mechanism of compressible flow, the effect of promotion of the convective region in stellar outer shell on the matter loss of stellar wind is investigated. Hence a new formula of matter loss of stellar wind is established. After this and via the computation of the rate of mass loss of stellar wind in the theoretical model of 3∼5Mө stars, the following is revealed. From the main sequence up to the stage of termination of central helium-core burning, the rate of mass loss of stellar wind calculated with the new formula agrees almost completely with that given by the classical formula. But in the TP-AGB stage the stellar model calculated with the new formula of mass loss of stellar wind is not affected by luminosity and gives rise to the persistent and large matter loss of stellar wind. This rather well agrees with the results of actual observations.

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