Humungous torch of the nearest neighbor of the sun breaks records

Scientists have seen the biggest flare ever recorded from the sun’s nearest neighbor, the star Proxima Centauri.

The research, conducted today in The astrophysical journal letters, was led by the University of Colorado Boulder and can help shape the life hunt outside the Earth’s solar system.

Astrophysicist CU Boulder Meredith MacGregor explained that Proxima Centauri is a small but powerful star. It sits just four light-years or more than 20 trillion miles from our own sun and presents at least two planets, one of which looks like Earth. It is also a red dwarf, the name for a class of stars that are extraordinarily small and dull.

Proxima Centauri has about one-eighth of the mass of our own sun. But do not let that fool you.

In their new study, MacGregor and her colleagues observed Proxima Centauri for 40 hours using nine telescopes on the ground and in space. In the process, they got a surprise: Proxima Centauri emitted an eruption, or an eruption of radiation that begins near the surface of a star, which is considered one of the most violent seen anywhere in the galaxy. .

“The star went from normal to 14,000 times brighter when seen in ultraviolet wavelengths in a matter of seconds,” said MacGregor, an assistant professor at the Center for Astrophysics and Space Astronomy (CASA) and the Department. Astrophysical and Planetary Sciences (APS) said. ) by CU Boulder.

The team’s findings point to new physics that could change the way scientists think about star flares. It also does not bode well for any squishy organism brave enough to live near the volatile star.

“If there was life on the planet closest to Proxima Centauri, it would have to look very different from anything on earth,” MacGregor said. ‘One man on this planet will go bad. ‘

Active stars

The star has long been a target for scientists hoping to find life outside the Earth’s solar system. Proxima Centauri is, to begin with, close. It also houses one planet, named Proxima Centauri b, which lives in what scientists call the habitable zone – an area around a star that has reached the right temperature range to house liquid water on the surface of a planet.

But there is a twist, MacGregor said: Red dwarfs, considered the most common stars in the galaxy, are also extraordinarily vivid.

“A lot of the exoplanets we’ve found so far are around these kinds of stars,” she said. ‘But the prisoner is that they are much more active than our sun. They are burning much more and more intensely. ‘

To see how much Proxima Centauri flares up, she and her colleagues embarked on a coup in the field of astrophysics: they showed nine different instruments on the star for 40 hours in 2019 for a few months. The eyes include the Hubble. Space Telescope, the Atacama Large Millimeter Array (ALMA) and NASA’s Transiting Exoplanet Survey Satellite (TESS). Five of them recorded the enormous torch of Proxima Centauri and captured the event because it produced a wide spectrum of radiation.

“This is the first time we’ve had this kind of multi-wavelength coverage of a star torch,” MacGregor said. “Usually you’re lucky if you can get two instruments.”

Crispy planet

The technique has yielded one of the deepest anatomies of a torch of any star in the galaxy.

The event in question was observed on May 1, 2019 and lasted only 7 seconds. Although it did not produce much visible light, it caused a huge increase in ultraviolet and radio, or ‘millimeter’ radiation.

“In the past, we did not know that stars could flare up in the millimeter range, so this is the first time we are going to look for millimeter flares,” MacGregor said.

The millimeter signals, MacGregor added, could help researchers gather more information about how stars generate torches. Currently, scientists suspect that these bursts of energy occur when magnetic fields rotate near a star’s surface and strike with explosive consequences.

In total, the torch observed was about 100 times stronger than any similar torch seen from the earth’s sun. Over time, such energy can remove the atmosphere of a planet and even expose life forms to lethal radiation.

That torch may not be a rare occurrence on Proxima Centauri. In addition to the great boom in May 2019, the researchers recorded many other torches during the 40 hours they watched the star.

“Proxima Centauri’s planets are not hit by something like this once in a century, but at least once a day, even if not several times a day,” MacGregor said.

The findings suggest that the sun’s closest companion may present more surprises.

“There will probably still be strange kinds of torches showing different kinds of physics that we have not thought of before,” MacGregor said.