The three stars in the Alpha Centauri system are right next-door to us in the big neighborhood that is the Milky Way, lying just four light-years away from Earth. As our closest neighbor, this three-star system is the nearest place we can start looking for life outside the boundaries of our solar system.
And, as it turns out, two of the stars in Alpha Centauri system might be “friendly to life,” reports CNET.
According to a study that has been going on for more than a decade, any prospective planets that might be orbiting these two stars “are likely not being pummeled by large amounts of X-ray radiation from their host stars,” NASA announced recently.
The space agency has been keeping tabs on Alpha Centauri with the help of the Chandra X-Ray Observatory, one of the Great Observatories orbiting our planet and the world’s most powerful X-ray telescope.
Launched in 1999, Chandra has been scouring Alpha Centauri ever since 2005, monitoring the X-ray radiation and Space Weather (particles ejected by stellar flares) around the system’s three stars.
“X-rays and related Space Weather effects are bad for unprotected life, directly through high radiation doses and indirectly through stripping away planetary atmospheres (a fate thought to have been suffered by Mars in our own Solar System),” NASA officials explain in a news release.
What The Chandra Study Uncovered
After 13 years of study, Chandra revealed that at the two brightest stars in the Alpha Centauri system, dubbed Alpha Cen A and Alpha Cen B (or AB for short, when taken as a pair), could actually be favorable to the formation of life.
The results show that Alpha Cen A — which NASA states “is a near twin of our sun in almost every way, including age” — actually emits less X-ray radiation than the sun. This means that, if there are any planets orbiting this star, they’re much better off in terms of radiation exposure than the planets close to the sun.
At the same time, its somewhat smaller and dimmer companion star, Alpha Cen B, was found to bombard the habitable zone around it, where hidden planets might be lurking with slightly more radiation than the sun normally gives off.
As NASA points out, the X-ray dose blasting off of Alpha Cen B is higher than that of the sun by only a factor of five.
The findings were presented this week at the 232nd meeting of the American Astronomical Society in Denver, Colorado, by Tom Ayres of the University of Colorado Boulder.
Ayres, who published some of these results in the Research Notes of the American Astronomical Society at the beginning of 2018, chimed in on the Chandra discovery.
“This is very good news for Alpha Cen AB in terms of the ability of possible life on any of their planets to survive radiation bouts from the stars. Chandra shows us that life should have a fighting chance on planets around either of these stars.”
What Of Proxima Centauri?
The third star in the Alpha Centauri system, however, is a completely different story. Named Alpha Cen B, or Proxima Centauri, this is the closest star to Earth among the three, and also the most violent.
As the Inquisitr previously reported, Proxima Centauri is the nearest star to our planet other than the sun. Considerably smaller than Alpha Cen AB, this red dwarf star is very active and batters its only known planet, the Earth-sized Proxima b, with deadly radiation that most likely makes it inhospitable to life.
NASA reveals that Proxima b is pummeled with 500 times more radiation than our planet — and the amount can quickly climb to 50,000 larger than on Earth in the event of a big flare.