Harvard-Smithsonian Center for Astrophysics | 2015 Nov 19
[c][attachment=0]base[1].jpg[/attachment][/c][hr][/hr]Our Sun is a relatively quiet star that only occasionally releases solar flares or blasts of energetic particles that threaten satellites and power grids. You might think that smaller, cooler stars would be even more sedate. However, astronomers have now identified a tiny star with a monstrous temper. It shows evidence of much stronger flares than anything our Sun produces. If similar stars prove to be just as stormy, then potentially habitable planets orbiting them are likely to be much less hospitable than previously thought.
"If we lived around a star like this one, we wouldn't have any satellite communications. In fact, it might be extremely difficult for life to evolve at all in such a stormy environment," says lead author Peter Williams of the Harvard-Smithsonian Center for Astrophysics (CfA).
The research team targeted a well-known red dwarf star located about 35 light-years from Earth in the constellation Boîtes. The object is so small and cool that it's right on the dividing line between stars (which fuse hydrogen) and brown dwarfs (which don't). One of the things that makes this small star remarkable is that it spins rapidly, completing a full rotation about every 2 hours. Compare that with our Sun, which takes nearly a month to spin once on its axis.
Previous data from the Karl G. Jansky Very Large Array in Socorro, NM showed that this star has a magnetic field several hundred times stronger than our Sun. This puzzled astronomers because the physical processes that generate the Sun's magnetic field shouldn't operate in such a small star. ...
Cool, Dim Dwarf Star is Magnetic Powerhouse
National Radio Astronomy Observatory | 2015 Nov 19
The First Millimeter Detection of a Non-Accreting Ultracool Dwarf - P. K. G. Williams et al
- arXiv.org > astro-ph > arXiv:1511.05559 > 17 Nov 2015