• Corpus ID: 14929928

M Star Astrosphere Size Fluctuations and Habitable Planet Descreening

@article{Smith2009MSA,
  title={M Star Astrosphere Size Fluctuations and Habitable Planet Descreening},
  author={David S. Smith and John Michael Scalo},
  journal={arXiv: Earth and Planetary Astrophysics},
  year={2009}
}
Stellar astrospheres—the plasma cocoons carved out of the interstellar medium by stellar winds—are continually influenced by th eir passage through the fluctuating interstellar medium (ISM). Inside d ense interstellar regions, an astrosphere may be compressed to a size smaller than the liquidwater habitable zone distance. Habitable planets then enjoy no astrospheric buffering from the full flux of Galactic cosmic rays and inter stellar dust and gas, a situation we call “descreening.” Recent… 

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References

SHOWING 1-10 OF 79 REFERENCES
Cosmic ray impact on extrasolar earth-like planets in close-in habitable zones.
TLDR
It is shown that close-in extrasolar planets in the habitable zone of M stars are synchronously rotating with their host star because of the tidal interaction, and it is proposed that, depending on atmospheric pressure, biological systems on the surface of Earth-like Extrasolar planets at close- in orbital distances can be strongly influenced by secondary cosmic rays.
M stars as targets for terrestrial exoplanet searches and biosignature detection.
TLDR
It is concluded that attempts at remote sensing of biosignatures and nonbiological markers from M star planets are important, not as tests of any quantitative theories or rational arguments, but instead because they offer an inspection of the residues from a Gyr-long biochemistry experiment in the presence of extreme environmental fluctuations.
A reappraisal of the habitability of planets around M dwarf stars.
TLDR
It is concluded that M dwarf stars may indeed be viable hosts for planets on which the origin and evolution of life can occur and it makes sense to include M dwarfs in programs that seek to find habitable worlds and evidence of life.
Terrestrial atmospheric effects induced by counterstreaming dense interstellar cloud material
The Solar System during its life has travelled more than 10 times through dense interstellar clouds with particle concentrations of 10 2 -10 3 cm -3 and more, compressing the heliosphere to
Consequences of a past encounter of the earth with an interstellar cloud
In its motion through the galaxy the sun may have suffered a number of encounters with dense interstellar clouds for which the number density of molecular hydrogen H2 is > 10³ cm−3. Several authors
Habitable zones around main sequence stars.
TLDR
The results suggest that mid-to-early K stars should be considered along with G stars as optimal candidates in the search for extraterrestrial life.
Passing through a giant molecular cloud: “Snowball” glaciations produced by interstellar dust
In its motion through the Milky Way galaxy, the solar system encounters an average ‐density (≥330 H atoms cm−3) giant molecular cloud (GMC) approximately every 108 years, a dense (∼2 × 103 H atoms
Stellar wind regimes of close-in extrasolar planets
Close-in extrasolar planets of Sun-like stars are exposed to stellar wind conditions that differ considerably from those for planets in the solar system. Unfortunately, these stellar winds belong to
Coronal mass ejection (CME) activity of low mass M stars as an important factor for the habitability of terrestrial exoplanets. I. CME impact on expected magnetospheres of Earth-like exoplanets in close-in habitable zones.
TLDR
It is shown that Earth-like exoplanets within close-in HZs should experience a continuous CME exposure over long periods of time, which may result in little or no magnetospheric protection of planetary atmospheres from a dense flow of CME plasma.
The Heliosphere in Time
Because of the dynamic nature of the interstellar medium, the Sun should have encountered a variety of different interstellar environments in its lifetime. As the solar wind interacts with the
...
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2
3
4
5
...