If you read science fiction or science fact, you know the nearest star to the sun is called Proxima Centauri, a tiny red dwarf that happens to lay on this side of its triple star system containing Alpha Centauri A and B. Since its so close, astronomers have been able to mostly eliminate the chances of a really large unseen companion in close orbit around the little star, like a brown dwarf or a hot Jupiter. But the possibility of smaller planets exists and there’s reason to think there could be a few. Now, astronomers may get a chance to find out:
HNGN — “Proxima Centauri’s trajectory offers a most interesting opportunity because of its extremely close passage to the two stars,” said Kailash Sahu, an astronomer with the Space Science Telescope Institute in Baltimore. Md. Sahu leads a team of scientists whose work he presented Monday at the 222nd meeting of American Astronomical Society in Indianapolis.
According to Northwestern College, though red dwarfs make up for more than 50 percent of stars in the Milky way, not one of them is visible to the naked eye in the northern hemisphere. Previously, scientists have tried looking for planets around the Proxima Centauri but have not been successful. However, scientists are hopeful that this rare stellar alignment will give them the opportunity to spot smaller terrestrial planets, if they exist, by looking for microlensing effects.
The reason we think this red dwarf could have a healthy retinue of planets is because we know other red dwarfs do have them. Particularly Gliese 581, which is now thought to have almost half a dozen worlds, some of them are probably terrestrial and we know two of those are in or near the habitable zone where liquid water could exist on the surface of an earth-like planet. What might a really watery world in close orbit about such a star look like?
Maybe something like that. The thing about these little red dwarfs is they tend to be very active. Lots of flares, tons of coronal ejections, which means great showers of energized particles hitting the top of the planet’s atmosphere causing all sorts of displays. Made even more intense because the water planet would have to be very close. In the case of Proxima it would have to be so close its “year” would last about a week or less. The good thing about that is it means the planet’s day would be about the same, any world would be tidally locked, and that might be fast enough to preserve a magnetic moment which would deflect some charged particles, a necessity for any nearby world that wanted to hang onto its atmosphere.