Humongous, Record-Breaking Stellar Flare From Sun’s Nearest Neighbor

Violent Stellar Flare Proxima Centauri

Artist’s conception of a violent stellar flare erupting on neighboring star, Proxima Centauri. The flare is the most powerful ever recorded from the star, and is giving scientists insight into the hunt for life in M dwarf star systems, many of which have unusually lively stars. Credit: NRAO/S. Dagnello

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

The research, which was published recently in The Astrophysical Journal Letters, was led by CU Boulder and could help to shape the hunt for life beyond Earth’s solar system.

CU Boulder astrophysicist Meredith MacGregor explained that 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 hosts at least two planets, one of which may look something like Earth. It’s also a “red dwarf,” the name for a class of stars that are unusually petite and dim. 

Proxima Centauri has roughly one-eighth the mass of our own sun. But don’t 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 ejected a flare, or a burst of radiation that begins near the surface of a star, that ranks as 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 over the span of a few seconds,” said MacGregor, an assistant professor at the Center for Astrophysics and Space Astronomy (CASA) and Department of Astrophysical and Planetary Sciences (APS) at CU Boulder.

Stellar Flare Proxima Centauri b

Artist’s conception of a violent stellar flare erupting on neighboring star, Proxima Centauri. The flare is the most powerful ever recorded from the star, and is giving scientists insight into the hunt for life in M dwarf star systems, many of which have unusually lively stars. Artist’s conception of a violent stellar flare erupting on neighboring star, Proxima Centauri. The flare is the most powerful ever recorded from the star, and is giving scientists insight into the hunt for life in M dwarf star systems, many of which have unusually lively stars. Credit: NRAO/S. Dagnello

The team’s findings hint at new physics that could change the way scientists think about stellar flares. They also don’t bode well for any squishy organism brave enough to live near the volatile star.

“If there was life on the planet nearest to Proxima Centauri, it would have to look very different than anything on Earth,” MacGregor said. “A human being on this planet would have a bad time.”

Active stars

The star has long been a target for scientists hoping to find life beyond Earth’s solar system. Proxima Centauri is nearby, for a start. It also hosts one planet, designated Proxima Centauri b, that resides in what researchers call the “habitable zone”—a region around a star that has the right range of temperatures for harboring liquid water on the surface of a planet.

But there’s a twist, MacGregor said: Red dwarves, which rank as the most common stars in the galaxy, are also unusually lively.

“A lot of the exoplanets that we’ve found so far are around these types of stars,” she said. “But the catch is that they’re way more active than our sun. They flare much more frequently and intensely.”

To see just how much Proxima Centauri flares, she and her colleagues pulled off what approaches a coup in the field of astrophysics: They pointed nine different instruments at the star for 40 hours over the course of several months in 2019. Those eyes included the Hubble Space Telescope, the Atacama Large Millimeter Array (ALMA) and NASA’s Transiting Exoplanet Survey Satellite (TESS). Five of them recorded the massive flare from Proxima Centauri, capturing the event as it produced a wide spectrum of radiation.

“It’s the first time we’ve ever had this kind of multi-wavelength coverage of a stellar flare,” MacGregor. “Usually, you’re lucky if you can get two instruments.”

Crispy planet

The technique delivered one of the most in-depth anatomies of a flare from any star in the galaxy.

The event in question was observed on May 1, 2019, and lasted just 7 seconds. While it didn’t produce a lot of visible light, it generated a huge surge in both ultraviolet and radio, or “millimeter,” radiation. 

“In the past, we didn’t know that stars could flare in the millimeter range, so this is the first time we have gone looking for millimeter flares,” MacGregor said. 

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

In all, the observed flare was roughly 100 times more powerful than any similar flare seen from Earth’s sun. Over time, such energy can strip away a planet’s atmosphere and even expose life forms to deadly radiation.

That type of flare may not be a rare occurrence on Proxima Centauri. In addition to the big boom in May 2019, the researchers recorded many other flares during the 40 hours they spent watching the star.

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

The findings suggest that there may be more surprises in store from the sun’s closest companion. 

“There will probably be even more weird types of flares that demonstrate different types of physics that we haven’t thought about before,” MacGregor said.

For more on this discovery. read Violent Stellar Flare From Sun’s Nearest Neighbor Breaks Record.

Reference: “Discovery of an Extremely Short Duration Flare from Proxima Centauri Using Millimeter through Far-ultraviolet Observations” by Meredith A. MacGregor, Alycia J. Weinberger, R. O. Parke Loyd, Evgenya Shkolnik, Thomas Barclay, Ward S. Howard, Andrew Zic, Rachel A. Osten, Steven R. Cranmer, Adam F. Kowalski, Emil Lenc, Allison Youngblood, Anna Estes, David J. Wilner, Jan Forbrich, Anna Hughes, Nicholas M. Law, Tara Murphy, Aaron Boley and Jaymie Matthews, 21 April 2021, The Astrophysical Journal Letters.
DOI: 10.3847/2041-8213/abf14c

Other coauthors on the new study include Steven Cranmer, associate professor in APS and the Laboratory for Atmospheric and Space Physics (LASP) at CU Boulder; Adam Kowalski, assistant professor in APS and LASP at CU Boulder, also of the National Solar Observatory; Allison Youngblood, research scientist at LASP; and Anna Estes, undergraduate research assistant in APS. 

The Carnegie Institution for Science, Arizona State University, NASA Goddard Spaceflight Center, University of Maryland, University of North Carolina at Chapel Hill, University of Sydney, CSIRO Astronomy and Space Science, Space Telescope Science Institute, Johns Hopkins University, the Center for Astrophysics | Harvard & Smithsonian and the University of British Columbia also contributed to this research. 

8 Comments on "Humongous, Record-Breaking Stellar Flare From Sun’s Nearest Neighbor"

  1. Walker Hall | May 6, 2021 at 4:54 pm | Reply

    It’s humongous. Humungus is not a word. 🙂

    • Mike O'Neill | May 6, 2021 at 8:32 pm | Reply

      Thanks for the note. The spelling has been updated.

      However, note that humungous is indeed a word. It is the common UK spelling, where humongous is the preferred spelling in the US. Since SciTechDaily prefers US spelling and grammar, I updated that title.

  2. Chris fairbanks | May 7, 2021 at 9:32 pm | Reply

    The text under the photo cannot be read because some of it runs outside the screen and I cannot scroll over to see them. This is a problem in both portrait and landscape mode. I am using an Android phone and chrome browser. I’ve seen this kind of thing on your articles before.

  3. I gotta laugh. The Earth is flat. Space is a cartoon for grown ups. Show one scientific method experiment that shows you can create gas pressure without a container and on top of it ” planets” are in an infinite vacuum.

  4. Space is FAKE | May 8, 2021 at 10:47 pm | Reply

    A gas giant is a spinning ball of gas that’s traveling through a universe at 400 million miles an hour like Jupiter . Space is supposed to be an infinite vacuum and the vacuum over 10 times stronger than anything we can make on Earth. They took steel railroad cars and suck the air out of the 4 in thick cars and created a vacuum 1/20 as strong as the one that supposedly in space and the railroad car imploded. Tell me how are the spinning balls of gas not dissipating in a vacuum that is supposed to be billions of light years across?

    • Because gravity pulls the air molecules down towards the surface. Imagine an invisible string for each air molecules, tethering it close to the ground.

Leave a comment

Email address is optional. If provided, your email will not be published or shared.