A new study of red dwarfs has shown that even the quietest examples of this class of stars are more active and ferocious than the sun. red dwarfsDwarfs, officially known as “M dwarfs” by astronomers, are the most common stars in the Milky Way and can remain dormant for long periods before transforming into massive stars.super flares“. Previously, these eruptions were found to be 100-1000 times more powerful than similar solar flares, especially violent young red dwarfs.

These flares are also known as red-hot plasma eruptions. coronal mass ejection (CMES) can be incredibly destructive to planets orbiting red dwarfs, destroying their atmospheres and emitting enough radiation to boil liquid water even in supposedly habitable places. The perihelion region is the region around a star where liquid water can be found on the Earth’s surface.

One of the systems that astronomers are particularly keen on finding potential signs of life is, TRAPPIST-1contains seven Earth-sized planets, of which at least three are in the habitable zone. However, TRAPPIST-1 is a red dwarf, and if it explodes in violent bursts like a red dwarf Proxima CentauriEmitting a flare 14,000 times brighter than its pre-flare brightness in 2019, TRAPPIST-1’s life potential may be relatively low.

The team behind the new study, including scientists from France, Portugal and Switzerland, examined observations of 177 red dwarfs collected between 2003 and 2020 by the High Sensitivity Radio Fast Planet Search (HARPS), an instrument in the 3.6-metre telescope. La Observatory Silla from the European Southern Observatory. This allowed them to characterize the long-term variability of these red dwarf stars.

All stars exhibit some degree of variability; For example, the sun has an activity cycle of about 11 years. During this cycle sunspots increase and decrease on the surface of our star. The increase in the number of sunspots caused by magnetic activity results in increased intensity of solar flares and space weather.

Fortunately, life begins and evolves on time scales much larger than solar cycles. For example, on Earth life appeared about 4 billion years ago, about 500 million years after the formation of our planet. In other parts of life Milky Way If it develops over a similar period of time, the long-term variability and ferocity of red dwarfs could significantly alter this process.

To investigate variability in red dwarf activity, the team turned to HARPS data, as the instrument is particularly useful for determining how active stars are. This is because the star faces radiation from its atmosphere, the second layer of its atmosphere, the chromosphere. Emissions from this layer are caused by magnetic activity such as flares, rather than fusion occurring in the cores of stars.

As astronomers try to study individual red dwarfs in detail, the next best thing is to observe large numbers of these stars over long periods of time. Long research is needed to get a truly clear picture of red dwarf variability, but such data are limited.