Exoplanet Near Earth’s Nearest Star Might Have Been Scorched by Gigantic Solar Flare

“It’s likely that Proxima b was blasted by high energy radiation during this flare. Over the billions of years since Proxima b formed, flares like this one could have evaporated any atmosphere or ocean and sterilized the surface, suggesting that habitability may involve more than just being the right distance from the host star to have liquid water.”

– Meredith MacGregor, Ph.D., Astronomer, Carnegie Institution, Washington, D. C.

March 6, 2018 Albuquerque, New Mexico – A year ago on March 24, 2017, one of Earth’s nearest stars beyond our own sun — Proxima Centauri — unleashed a solar flare that grew in brightness by 1,000 times in ten seconds compared to the normal Proxima Centauri sun. The enormous hot flare lasted for approximately one minute. All that heat and light must have scorched nearby exoplanet Proxima b, a planet 30% more massive than Earth, which orbits near Proxima Centauri.

The two main stars are Alpha Centauri A and Alpha Centauri B, which form a binary pair. They are an average of 4.3 light-years from Earth. The third star is Proxima Centauri. It is about 4.22 light-years from Earth and is the closest star other than the sun.

Alpha Centauri A and B orbit a common center of gravity every 80 years. The average distance between them is about 11 astronomical units (AU) — about the same distance as the sun is to Uranus. Proxima Centauri is about one-fifth of a light-year or 13,000 AUs from the two other stars, a distance that makes some astronomers question whether it should be considered part of the same system.

Alpha Centauri (image above) is in a close star system of Alpha Centauri B and Proxima Centauri around which orbits Proxima b, an apparent rocky planet that is 1.3 times the mass of Earth. Red dwarf star Proxima Centauri, at 4.2 light-years away, is the closest star to our Earth. Image by NASA and ESA.
Alpha Centauri (image above) is in a close star system of Alpha Centauri B and Proxima Centauri around which orbits Proxima b, an apparent rocky planet that is 1.3 times the mass of Earth. Red dwarf star Proxima Centauri, at 4.2 light-years away, is the closest star to our Earth. Image by NASA and ESA.
Once Upon A Time, Proxima b Was Thought Habitable
NASA artist's impression of planet Proxima b orbiting red dwarf star Proxima Centauri, at 4.2 light-years away, it is the closest star to our Earth. Proxima b is 1.3 times Earth's mass.
NASA artist’s impression of planet Proxima b orbiting red dwarf star Proxima Centauri, at 4.2 light-years away, it is the closest star to our Earth. Proxima b is 1.3 times Earth’s mass. 
Click for larger image.

Ironically, only five months before on October 25, 2016, NASA had announced that the exoplanet Proxima b orbiting the red dwarf star Proxima Centauri — the closest star to our solar system — might be a rocky and habitable planet.

But recently astronomer Meredith MacGregor, Ph.D., astronomer in the Dept. of Terrestrial Magnetism at the Carnegie Institution in Washington, D. C., published in the February 26, 2018, Astrophysical Journal Letters her investigation of the March 24, 2017, Proxima Centauri solar flare that probably would have fried most surface life on Proxima b. (See Websites below.)

Dr. MacGregor told reporters, “It’s likely that Proxima b was blasted by high energy radiation during this flare. Over the billions of years since (planet) Proxima b formed, flares like this one could have evaporated any atmosphere or ocean and sterilized the surface, suggesting that habitability may involve more than just being the right distance from the host star to have liquid water.”

An artist’s impression of a flare from Proxima Centauri, modeled after the loops of glowing hot gas seen in the largest solar flares. An artist’s impression of the exoplanet Proxima b is shown in the lower right foreground. Proxima b orbits its star 20 times closer than the Earth orbits the Sun.  A flare 10 times larger than a major solar flare would blast Proxima b with 4,000 times more radiation than the Earth gets from our Sun’s flares. Credit: Roberto Molar Candanosa / Carnegie Institution for Science, NASA/SDO, NASA/JPL.
An artist’s impression of a flare from Proxima Centauri, modeled after the loops of glowing hot gas seen in the largest solar flares. An artist’s impression of the exoplanet Proxima b is shown in the lower right foreground. Proxima b orbits its star 20 times closer than the Earth orbits the Sun.  A flare 10 times larger than a major solar flare would blast Proxima b with 4,000 times more radiation than the Earth gets from our Sun’s flares. Credit: Roberto Molar Candanosa / Carnegie Institution for Science, NASA/SDO, NASA/JPL.

Also see:

03-30-2017 – Repeating Fast Radio Bursts 2.5 Billion Light-Years from Earth — Alien Intelligence?


More Information:

Please see other Earthfiles exoplanet news:

05-26-2017 – Part 1 – Aliens: Scientists Search for Extraterrestrial Life
05-26-2017 – Part 2 – Aliens: Scientists Search for Extraterrestrial Life
05-17-2017 – Proxima Centauri, Closest Star to Earth, Has Exoplanet Where Temperature and Water Might Make It Habitable
04-05-2016 – Interstellar Travel with Laser Light Propulsion


Websites:

“Detection of a Millimeter Flare from Proxima Centauri,” February 26, 2018, Astrophysical Journal Letters: http://iopscience.iop.org/article/10.3847/2041-8213/aaad6b/meta

Alpha Centauri A and Alpha Centauri B and Proxima Centauri Star System Closest to Earth: https://en.wikipedia.org/wiki/Alpha_Centauri


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