BELLINGHAM – About four light years away from our planet sits Proxima Centauri, the closest star to our solar system, and orbiting it is its just-discovered companion, a small Earth-like planet that, for now at least, holds the unassuming name of Proxima b.
At this distance, Proxima b is, in interstellar terms, a next-door neighbor even though a probe such as Voyager, if launched today, would take about 75,000 years to reach it.
“We’ve discovered other planets before, but not this close to us,” said James Davenport, a postdoctoral researcher in Western Washington University’s Physics and Astronomy Department. “What is doubly exciting is that Proxima b sits right in the ‘Goldilocks Zone’ of its parent star – not too close for the heat to boil off the planet’s atmosphere, not too far for it to be a ball of ice. It’s at just the right distance for a pleasant atmosphere and because of that, potentially, life.”
But not all the news is good.
Davenport is part of a five-person team led by David Kipping at Columbia University researching the nasty tendency of Proxima Centauri, the parent star, to produce massive solar flares that can be as large as 10 times bigger than anything produced by our sun. These superflares have the ability to strip the atmosphere off nearby planets with each episode, which produces a huge bombardment of X-Rays and ultraviolet rays to anything nearby.
“It would take years for our planet to recover from one of these types of superflares, based on the best models,” Davenport said. “But Proxima emits them about eight times a year, and mostly likely has been doing so for quite some time.”
Because we know so little about Proxima b, and it will take years of intense study before we can glean much from the planet, Davenport said the million-dollar question – could there be life there – remains unanswerable.
“There are a ton of theories that support the ability of the planet to ‘shield itself’ from the flares, so we can’t write it off just yet,” he said. “To get a better look at the planet, we’ll need to use something big like the Hubble or James-Webb space telescope.”
Currently, the team gathers its solar-flare data from images from the MOST space telescope, a smaller, suitcase-sized Canadian telescope launched 13 years ago.
“MOST is perfect for our needs, as we can have it staring at Proxima for weeks at a time,” he said.
The other members of Davenport’s team are Kipping, Dimitar Sasselov of Harvard University, Jaymie Matthews of the University of British Columbia, and Chris Cameron of Cape Breton University. The team has submitted a paper of their results to the Astrophysical Journal Letters, and they are continuing to examine the data for signs of how the flares could impact, for good or for ill, the ability of the planet to harbor life.
“The eye of the science world is about to turn to Proxima b,” he said.
Davenport is in the second of a three-year postdoctoral research fellowship funded by the National Science Foundation. Raised in Yakima, Davenport received his doctorate from the University of Washington in 2015. For information on his research into Proxima Centauri, contact him at [email protected]