University of Rochester | 2016 Mar 22
New theory helps explain and predict the activity of sun-like stars
[img3="It is easier to determine the age of star clusters than individual "field stars." For example, cluster NGC 1783 shown here is under one and a half billion years old — which is very young for globular clusters. The work by Blackman and Owen might ultimately lead to a new approach to determine a star's age. Image taken with the Advanced Camera for Surveys (ACS) on board the NASA/ESA Hubble Space Telescope."]http://cdn.spacetelescope.org/archives/ ... w1534a.jpg[/img3][hr][/hr]Researchers have developed a new conceptual framework for understanding how stars similar to our Sun evolve. Their framework helps explain how the rotation of stars, their emission of x-rays, and the intensity of their stellar winds vary with time. According to first author Eric Blackman, professor of physics and astronomy at the University of Rochester, the work could also “ultimately help to determine the age of stars more precisely than is currently possible.”
In a paper published today in Monthly Notices of the Royal Astronomical Society, the researchers describe how they have corroborated known, observable data for the activity of Sun-like stars with fundamental astrophysics theory. By looking at the physics behind the speeding up or slowing down of a star’s rotation, its x-ray activity, and magnetic field generation, Blackman says the research is a “first attempt to build a comprehensive model for the activity evolution of these stars”.
Using our Sun as the calibration point, the model most accurately describes the likely behavior of the Sun in the past, and how it would be expected to behave in the future. But Blackman adds that there are many stars of similar mass and radius, and so the model is a good starting point for predictions for these stars. ...
Minimalist coupled evolution model for stellar x-ray activity,
rotation, mass loss, and magnetic field - Eric G. Blackman, James E. Owen
- Monthly Notices of the RAS 458(2):1548 (2016 May 11) DOI: 10.1093/mnras/stw369
arXiv.org > astro-ph > arXiv:1511.05658 > 18 Nov 2015 (v1), 01 Mar 2016 (v3)