Dec 10, 2020 07:07 PM
(This post was last modified: Dec 10, 2020 07:07 PM by C C.)
https://theconversation.com/bad-space-we...uri-150979
EXCERPTS: If you look up in the southern sky you can see [...] Alpha Centauri, which is actually a pair of Sun-like stars that are too close together to tell apart by eye. There is a third member of the Alpha Centauri system as well: Proxima Centauri (Proxima Cen for short), which circles the central two stars in a wide orbit. This is the Sun’s nearest neighbour, at a distance of just 4.2 light years.
It is possible one of Proxima Cen’s planets is suitable for life. However, we recently detected the signature of fierce space weather from Proxima Cen, which implies an orbiting planet could be blasted with hazardous particles and magnetic fields.
Our Sun is a relatively unremarkable yellow dwarf star [...] Proxima Cen is very different. It is a red dwarf star, with a diameter only 15% of the Sun’s, and a surface temperature of 3,000K (degrees Kelvin), much cooler than the Sun’s 6,000K. ... We know Proxima Cen has at least two planets: Proxima Cen b, a rocky “super-Earth” located in the middle of Proxima Cen’s Goldilocks zone, and Proxima Cen c, a “sub-Neptune” located further out.
For years, astronomers have suspected planets like Proxima Cen b may be a dangerous home for life because they are so close to their host stars. Many red dwarf stars produce frequent, powerful flares – intense bursts of radiation travelling out into space. If planets like Proxima Cen b don’t have protective features such as a thick atmosphere or a strong magnetic field, they would be exposed to perilous levels of radiation.
[...] The most energetic space weather events are known as coronal mass ejections (or CMEs). These massive eruptions escape the atmosphere of a star and travel through space at millions of kilometres per hour. ... We have observed a radio burst signature implying a CME erupting from Proxima Cen. But to confirm the relationship of these stellar radio bursts with CMEs, we need to harness information from other wavelengths. Once we can do this, we should soon know exactly how hazardous it is to live next to a star like Proxima Centauri... (MORE - details)
EXCERPTS: If you look up in the southern sky you can see [...] Alpha Centauri, which is actually a pair of Sun-like stars that are too close together to tell apart by eye. There is a third member of the Alpha Centauri system as well: Proxima Centauri (Proxima Cen for short), which circles the central two stars in a wide orbit. This is the Sun’s nearest neighbour, at a distance of just 4.2 light years.
It is possible one of Proxima Cen’s planets is suitable for life. However, we recently detected the signature of fierce space weather from Proxima Cen, which implies an orbiting planet could be blasted with hazardous particles and magnetic fields.
Our Sun is a relatively unremarkable yellow dwarf star [...] Proxima Cen is very different. It is a red dwarf star, with a diameter only 15% of the Sun’s, and a surface temperature of 3,000K (degrees Kelvin), much cooler than the Sun’s 6,000K. ... We know Proxima Cen has at least two planets: Proxima Cen b, a rocky “super-Earth” located in the middle of Proxima Cen’s Goldilocks zone, and Proxima Cen c, a “sub-Neptune” located further out.
For years, astronomers have suspected planets like Proxima Cen b may be a dangerous home for life because they are so close to their host stars. Many red dwarf stars produce frequent, powerful flares – intense bursts of radiation travelling out into space. If planets like Proxima Cen b don’t have protective features such as a thick atmosphere or a strong magnetic field, they would be exposed to perilous levels of radiation.
[...] The most energetic space weather events are known as coronal mass ejections (or CMEs). These massive eruptions escape the atmosphere of a star and travel through space at millions of kilometres per hour. ... We have observed a radio burst signature implying a CME erupting from Proxima Cen. But to confirm the relationship of these stellar radio bursts with CMEs, we need to harness information from other wavelengths. Once we can do this, we should soon know exactly how hazardous it is to live next to a star like Proxima Centauri... (MORE - details)