New York, April 22
Scientists have seen the largest flare ever recorded by the Sun’s closest neighbor, star Proxima Centauri.
Proxima Centauri is a small but mighty star. It sits just four light years or more than 20 trillion miles from our own Sun and supports at least two planets, one of which can look like Earth.It’s also “red dwarf,” the name of a class of stars that are unusually petite and dim, explained Meredith MacGregor, an astrophysicist at the University of Colorado Boulder.
For the new study, published in the Astrophysical Journal Letters, the team observed Proxima Centauri for 40 hours using nine telescopes on the ground and in space.
They found Proxima Centauri having thrown a flare, or a burst of radiation that begins near the surface of a star, which rates as one of the most violent seen anywhere in the galaxy. The flare was about 100 times more powerful than any similar flare seen from the Earth’s sun. Over time, such energy can obliterate the atmosphere of a planet and even expose life forms to deadly radiation.
“The star went from normal to 14,000 times brighter when viewed in ultraviolet wavelengths over a few seconds,” said MacGregor.
The team’s findings suggest a new physics that could change the way scientists think about stellar flares. Neither do they bode well for any squishy organism brave enough to live near the ever-shifting star.
Instruments included the Hubble Space Telescope, the Atacama Large Millimeter Array and the NASA Transit Exoplanet Survey Satellite. Five of them recorded the massive flare by Proxima Centauri, capturing the incident as it produced a broad spectrum of radiation.
The technique presented one of the most detailed anatomies of any star in the galaxy. Although it did not produce much visible light, it did produce a huge surge in ultraviolet and radio radiation, or “millimeter” radiation.
“In the past, we didn’t know that stars could flame in the millimeter range, so this was the first time we went looking for millimeter flares,” said MacGregor.
Those millimeter signals, MacGregor added, could help researchers gather more information about how stars produce flares. IANS