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Mo 4. Jan 2021, 09:37
Terrible space weather could make life impossible near Proxi
If you look up into the southern sky, you will see a "pointer" star pointing to the constellation of the Southern Cross. One of these pointers is Alpha Centauri, a pair of sunlike stars that are too close to each other by eye.There is also a third member of the Alpha Centauri system: Proxima Centauri (Proxima Cen for short), which circles two central stars in a wide orbit. This is the Sun's nearest neighbor, at a distance of just 4.2 light years.It is possible that one of Proxima Cen's planets is suitable for life. Recently, however, we detected a signature of extreme space weather from Proxima Cen, showing that orbiting planets could be destroyed by harmful particles and magnetic fields.Our neighbors are not like the sun. Our Sun is the only known unusual yellow dwarf in the universe: our planet.
Proxima Cen is very different. It is a red dwarf with only 15% of the diameter of the สล็อต Sun and a surface temperature of 3,000 K (degrees Kelvin), much colder than the Sun's 6,000K.Because the Proxima Cen is relatively cool, the "Goldilocks" region of orbit around it, whose temperature is optimal for liquid water, is about one-twentieth of the Earth's distance from the Sun. We are interested in planets in the star's Goldilocks region because liquid water is as essential for life as we know it.We know that Proxima Cen has at least two planets: Proxima Cen b, a rocky "super-Earth" located in the center of Proxima Cen's Goldilocks region, and Proxima Cen c, the "sub-Neptune" located. Away For years, astronomers have wondered whether planets such as Proxima Cen b could be a dangerous home for life because they are so close to their satellites. Many red dwarfs produce powerful flares, often - intense radiation that goes out into space. If a planet like Proxima Cen b lacks protective properties, such as a dense atmosphere or a strong magnetic field, it is exposed to dangerous levels of radiation.
But what's the weather around these stars?
Red dwarfs' space weather is another important factor in determining how generous they are for life. While flames are associated with violent explosions of light. But space weather events mean magnetic fields and electrically charged particles from stars can interact directly with planets.The most energetic space weather events are called corona ejection (or CME) .These massive eruptions escape the star's atmosphere and travel through space at speeds of millions of kilometers per hour.If space weather is severe enough, the planet's atmosphere can be blown away and its magnetic field can be pushed backwards, exposing the surface to deadly flare.CMEs have been detected around the sun since the 1970s, but detecting space weather events around distant stars is much more difficult.
For updates on weather, visit Radio.CMEs on the Sun generate distinctive radio noise such as “Category II” and “Category IV” bombs. By detecting similar signatures on other stars, we can indirectly identify the stellar CME.In early 2019, we pointed our telescope at Proxima Cen for 11 nights.We used CSIRO's new radio telescope, the Australian Square Kilometer Array Pathfinder (ASKAP), as well as the Zadko Telescope, the ANU 2.3m Telescope, and the Transiting Exoplanet Observation Satellite. NASA's Exoplanet (TESS)Our goal is to detect CME signatures.On the night of May 2, 2019, we noticed a huge flare with a total energy of about 16 septillion joules (that is, the value of Australia's current generation of electricity, almost 17 million years) .On Sunday, only one of this massive fireworks will occur. It's been a decade or two, but in Proxima Cen it happens every few weeks.
Using ASKAP, we noticed a violent sequence of radio explosions.With the remarkable detail revealed with ASKAP, we can see that we can detect the best example of a type IV solar-like explosion from another star.This radio explosion shows the space weather around Proxima Cen is very intense.A single swallow does not make the summer"In 1859, British astronomers Richard Carrington and Richard Hodgson made the first observations of the solar flare, which was followed by a massive space weather storm that name "The Carrington Event" We now know that the storm was caused by a massive ejection of the corona mass that hit the Earth.Carrington noted the fluke during these special events. But be careful with the link between them stating that "One swallow doesn't make summer." We now find ourselves in a situation similar to Carrington.We have observed radio explosion signatures indicating CME eruptions from Proxima Cen, but to confirm the relationship of these stellar radio bursts with the CME, we need to control data from other wavelengths when we can. Yes, we should soon learn how dangerous it is to be next to a star like Proxima Centauri.