When we’re usually more accustomed to seeing distant stars, nebulae and galaxies through the lens of the Hubble Space Telescope, it may come as a surprise that even the sun’s nearest neighbor, Proxima Centauri, is still just a point of light in the great expanse of space. But the red dwarf star, located in the constellation of Centaurus, is over 4.2 light-years away — a short hop by interstellar proportions; still a marathon by anyone’s measure.
Red dwarf stars are curious objects. They’re small and dim, but have the habit of erupting in a flaring temper tantrum. In the case of Proxima, the star is not visible by the naked eye despite its relatively close proximity to our solar system. Proxima is known to undergo dramatic changes in brightness and is therefore a known “flare star.”
Exoplanet hunters have shown interest in hunting for small worlds in “habitable” orbits around red dwarfs as current exoplanet-hunting techniques favor the detection of worlds orbiting close to their host stars. As they output less energy than larger mass stars, red dwarfs’ habitable zones — the region surrounding a star where it’s neither too nor or too cold for liquid water to exist on a rocky planet’s surface — are much closer to the stars’ surface than, say, sun-like stars.
So long as any hypothetical extraterrestrial life in a red dwarf system has a high tolerance for the occasional eruption, red dwarfs could be touted as a good target for future exoplanet-hunting telescopes.
Another interesting fact about red dwarfs, that could boost their life-giving potential, is their longevity. According to a NASA/Hubble news release, “astronomers predict that (Proxima) will remain middle-aged — or a “main sequence” star in astronomical terms — for another four trillion years, some 300 times the age of the current Universe.” (Emphasis added.)
Considering our sun will reach the end of its life within approximately 5 billion years (and fry all life on Earth in less than half that time), stars like Proxima Centauri appear to be a better match for the evolution of life, perhaps nurturing lifeforms for tens, hundreds or even thousands of billions of years.
Currently, astronomers have no idea about the existence of any worlds around Proxima (although it does seem increasingly likely), although they have discovered a small (likely rocky) world around Alpha Centauri B, one of a binary pair of stars that Proxima is probably gravitationally bound.
Are there any exoplanets in this new Hubble photo of the sun’s nearest stellar neighbor? Who knows, but its certainly fun to imagine the potential for ancient alien lifeforms eking out an existence around these tiny red dwarf stars.
Image credit: ESA/Hubble & NASA