Proxima Centauri, our closest stellar neighbor, released a massive stellar flare in March of last year. The star was thought to host planets that could support extraterrestrial life. However, the eruption from last year reduces the chances of supporting extraterrestrial life, as the stellar flare was 10 times brighter compared to the largest flare coming from our Sun, according to a new paper.
Last year, scientists from the Institute of Astrophysics of Andalusia (IAA) in Spain announced the discovery of a glow surrounding Proxima Centauri. They thought that this glow was coming from a ring of dust, similar to the asteroid belt which orbits the Sun on the far side of Mars. They believed that this dust ring could mean that there is a planetary system which orbits together with the exoplanet Proxima b.
Basically, dust and asteroid belts are what is left from the accretion disc of dust that surrounds a forming star. This same dust can result in planet creation.
However, due to the massive stellar flare, the previous interpretation of the data seems flawed, according to a team of researchers led by Carnegie’s Meredith MacGregor.
Both of the teams analyzed 10 hours of data which was gathered by the Atacama Large Millimeter/submillimeter Array, radio telescope. The data was taken from between January 21 until April 25, 2017.
The IAA team used the average amount of light over the mentioned three months, including both the light of the star and massive stellar flare. The team focused on analyzing the light as a function of observing time, which led to a spike in the emission of the star.
On March 24, 2017, they discovered that the star erupted with the stellar flare and was 1,000 times brighter compared to the normal emissions of the star, over a period of 10 seconds. However, the event didn’t last longer than two minutes.
Proxima Centauri is very active when it comes to flare activity, so those massive fire explosions are not a complete surprise. Nevertheless, an explosion this huge lowers the chances for supporting life on Proxima b, which is a rocky planet with roughly 1.3 times the mass of Earth.
The star is quite cool and dim, which means that the planet would need to be orbiting quite close to be in the habitable zone, and also meaning it would likely be affected by stellar flares which could sweep away its atmosphere, if there ever was one in the beginning.
“It’s likely that Proxima b was blasted by high energy radiation during this flare,” MacGregor said in a statement. “Over the billions of years since Proxima b formed, flares like this one could have evaporated any atmosphere or ocean and sterilised the surface, suggesting that habitability may involve more than just being the right distance from the host star to have liquid water.”
Nevertheless, this discovery doesn’t mean that there is no extraterrestrial life on Centauri b. According to the report by Forbes, MacGregor said: “There are a lot of factors we still don’t understand. I hesitate to immediately squash it (the possibility of life.)”
The team checked the data from Chile’s ALMA Observatory. Their findings were published in the Astrophysical Journal Letters.