Life on Red Dwarf Stars

Study Notes

Factors Affecting the Likelihood of Life around Red Dwarf Stars

Red dwarf systems are unlikely to be habitable due to low stellar flux, high probability of tidal locking, and small circumstellar habitable zones.
The longevity and ubiquity of red dwarfs could provide ample opportunity for the possibility of habitability to be realized.
Intense tidal heating caused by proximity to red dwarf stars is a major impediment to life developing in these systems.
Extreme temperature differences created by one side of habitable-zone planets permanently facing the star, and the other perpetually turned away, reduces the probability of life around red dwarfs.
The evolution of red dwarf stars would mean a zone where water was not liquid but in its gaseous state, rendering terrestrial planets uninhabitable.
Tidal locking makes the planet rotate on its axis once every revolution around the star, creating great extremes of temperature.
Climate models indicate that cloud formation on tidally locked planets would minimize the temperature difference between the day and the night side, greatly improving habitability prospects for red dwarf planets.
Flares and star-spots experienced by red dwarfs could be very damaging for life, but if the planet had a magnetic field, it could deflect particles from the atmosphere.
Red dwarfs account for about 85% of stars in the Milky Way, and there are expected to be tens of billions of super-Earth planets in the habitable zones of red dwarf stars in the Milky Way.
Red dwarfs produce light energy for a very, very long time, and could exist for trillions of years, providing ample time for life to evolve and survive.
Moons of gas giants within a habitable zone could overcome tidal locking issues since they would become tidally locked to their primary, not their star.
The total amount of habitable zone around all red dwarfs combined is likely equal to the total amount around Sun-like stars given their ubiquity.Habitable Zone around Red Dwarf Stars
Gliese 581 is a red dwarf star that could have liquid water at its terminator.
Planets orbiting red dwarf stars can support an atmosphere due to their mass.
In the future, red dwarfs may become blue dwarfs, which could allow for life to appear and evolve on previously frozen planets.
Water retention is possible in the habitable zone of ultra-cool dwarfs, with a sweet spot in the 0.08 – 0.11 M⊙ range.
Water worlds orbiting M-dwarfs could lose their oceans over time due to intense radiation environments.
A second habitable zone could exist further out from the star where methane is liquid, allowing for methane-based life.
Studies estimate that Earth-sized worlds are around 30-45% likely to exist around ultra-cool dwarf stars.
TRAPPIST-1 (c. 0.084 M⊙) is likely to have planets similar in size to Earth.
Fictional examples of aliens in red dwarf star systems exist.
For more information, see the references and further reading sections.

Description

Explore the fascinating world of red dwarf stars and their potential for harboring life in this informative quiz. Discover the challenges and impediments that make it difficult for life to exist around these stars, such as low stellar flux and tidal locking, but also the opportunities that arise from their longevity and ubiquity. Learn about the latest research on the habitable zones around red dwarfs, the potential for water retention, and the possibility of methane-based life. Test your knowledge and expand your horizons with this engaging