Photo: from open sources
Science news:Proxima Centauri is a red dwarf, its habitable zone is much closer to the star than the habitable zone of the Sun.
American physicists figured out what would happen to the Earth’s atmosphere, if that turned around the star Proxima Centauri is roughly on the same orbit, exoplanet b, and Proxima. According to the authors, the rate of loss of the atmosphere in conditions of strong ultraviolet radiation and great activity of Proxima will be at least 10 thousand times bigger than this Earth. When different source data complete disappearance of the atmosphere will occur over a period of 100 million to 2 billion years, which is much less than the lifetime of Proxima b.
The existence of exoplanets like the earth, the nearest star to the Sun — Proxima Centauri — it became known a year ago . The project Pale Red Dot, after a long series of observations clearly indicated on the oscillations of the red dwarf, associated with the gravity of nearby exoplanets. Moreover, according to the discoverers, Proxima b is within the habitable zone of their stars, this means that on its surface there may exist liquid water.
However, a number of scientists of the potential habitability of Proxima b raised doubts. Proxima Centauri is a red dwarf, its habitable zone is much closer to the star than the habitable zone of the Sun. However, the activity of Proxima Centauri is associated with frequent outbreaks and a large proportion of ultraviolet radiation, which can be disastrous for the potential of life on the exoplanet. To protect the surface of Proxima b of these factors can have a fairly dense atmosphere comparable to earth — it was recently shown by the American physicist Dimitra Atri.
The creators of the work attempted to assess whether the existence of so dense the atmosphere of Proxima b. In their models of physics put the Earth as a well-studied model object is in orbit of the exoplanet and evaluated the possible rate of decrease of its atmosphere. The main reason for this process would be the impact of hard ultraviolet radiation of the stars, whose power is hundreds of times greater than ultra-violet radiation in the vicinity of this Land.
Hard ultraviolet radiation ionizes atmospheric gases, taking up electrons. After the negatively charged electrons leave the atmosphere of positively charged ions — most intensively it occurs near the magnetic poles. The authors, for double the Land in close proximity of Proxima Centauri this process will occur in 10 thousand times faster than for the Earth. This is equivalent to the fact that the total mass of the earth’s atmosphere will leave the planet in about 100 million years, or at the most optimistic forecasts, about two billion years. This is much less than the lifetime of Proxima b.
Physicists say that such calculations do not completely rule out the suitability of Proxima b to life. But the exoplanet has preserved the atmosphere, the mechanism of its occurrence must be very different from earth.
Red dwarfs — the most common class of stars. Most of the detected exoplanets are turning around such bodies and it attracts the attention of researchers looking for potentially habitable worlds. One of the most unusual of these systems is that TRAPPIST-1, red dwarf, some of which drawn by seven exoplanets, four of which are in the habitable zone.