New York, April 22
Scientists have identified the largest glow ever recorded from the Sun’s closest neighbor, the star Proxima Centauri.
Proxima Centauri is a small but mighty star. It is only four light years or more than 20 trillion miles from our Sun and is home to at least two planets, one of which may resemble Earth.It is also a “red dwarf,” the name of a class of unusually small and dark stars, explained Meredith MacGregor, an astrophysicist at the University of Colorado Boulder.
For the new study, published in Astrophysical Journal Letters, the team observed Proxima Centauri for 40 hours using nine telescopes on the ground and in space.
They found that Proxima Centauri emitted a glow, or burst of radiation that begins near the surface of a star, which ranks as one of the most violent ever seen in the galaxy. The glow was about 100 times more powerful than any similar glow seen from the Earth’s sun. Over time, such energy can clear a planet’s atmosphere and even expose life forms to deadly radiation.
“The star went from normal to 14,000 times brighter when viewed at ultraviolet wavelengths within seconds,” MacGregor said.
The team’s findings suggest new physics that could change the way scientists think about stellar flares. They also don’t bode well for any fluffy organism brave enough to live near the volatile star.
The instruments included the Hubble Space Telescope, the Atacama Large Millimeter Array, and NASA’s Transiting Exoplanet Survey Satellite. Five of them recorded the huge glow of Proxima Centauri, capturing the event as it produced a broad spectrum of radiation.
The technique has provided one of the most in-depth anatomies of a glow of any star in the galaxy. While it didn’t produce much visible light, it did generate a huge wave of both ultraviolet and radio, or “millimeter”, radiation.
“In the past, we didn’t know stars could flare in the millimeter range, so this is the first time we’ve been looking for millimeter flares,” MacGregor said.
Those millimeter signals, MacGregor added, could help researchers gather more information on how stars generate flare. IANS