Earths habitable planet Proxima Centauri, the closest star to our solar system, may have a lot in common with the Sun – but we don’t know if this is good news or bad news.
Earths habitable planet Proxima Centauri, dances with the sheer multitude of stars and planets in the Milky Way galaxy, you wouldn’t expect to find habitable planets right next door and, this might be, in fact, the case.
In August, astronomers announced that the nearby star Proxima Centauri hosts an Earth-sized planet (called Proxima b) in its habitable zone. We got a bit excited then, but our excitement was short lived. Proxima Centauri is nothing like our Sun, but still an Earths habitable planet Proxima Centauri.
Earths habitable planet Proxima Centauri, is a small, dim, red dwarf, about 1,000 times less luminous than the Sun. That hasn’t changed one bit, but the two stars do share a striking similarity: a sunspot cycle.
You missed a spot
Sunspots are darker spots of reduced temperature which are caused by concentrations of magnetic field flux that inhibit convection. They usually appear in pairs, of opposite magnetic polarity. Our Sun has an 11-year sunspot cycle: at the start of the cycle there almost no spots, and towards the end, an average 100 sunspots cover the star’s surface.
Proxima has a similar 7-year cycle, except it’s much more dramatic. At its peak, almost 20% of the star is covered by spots.
“If intelligent aliens were living on Proxima b, they would have a very dramatic view,” says lead author Brad Wargelin of the Harvard-Smithsonian Center for Astrophysics (CfA).
It was quite surprising to make this discovery because aside from the differences in size, the interior of the two stars is expected to be different.