Statement; Every Red Dwarf Star has at least One Planet
Think about that. Mull over that there are around 300 billion stars in the galaxy; around 500 billion galaxies in the Universe so that’s 1.5*10^23 stars; of which 75% of them are Red Dwarf stars (according to a study done by an international team of astronomers from the UK and Chile).
Take 75% of that number and there are approximately 1.125 * 10^23 Red Dwarf stars in the universe. AND each one of those has at least one planet.
So then that leads to another question; are they habitable?
That is best determined by the consideration of many factors.
A high probability of Tidal Locking exists and intense tidal heating due to the proximity is an impediment to the possibility of life. However, depending on their orbit and several other factors that may promote an atmosphere and magnetic shielding so they may be able to protect themselves from CMEs and Flares.
Low Stellar Flux: Flux means a measure of the amount of energy given off by an astronomical object over a fixed amount of time and area. So a low Stellar flux would make the measurement of that energy low. If the energy is low; how low is it? This could be important! Because they are very low in mass, red dwarfs have relatively low temperature in their cores and so energy is generated at a rather slow rate (through nuclear fusion of hydrogen & helium). As a result they often emit about 10% of our Sun’s luminosity. Because their radiation if emitted as infrared light (Earth plants use Ultraviolet light) so theoretically this might greatly impact the development of life, but that is based on the assumption that the life has needs as Earth’s life.
Of course there are other effects that run rampant on a Red Star. Intense cloud formations on the star facing side of a tidally locked planet can reduce the thermal flux or the transfer of heat energy throughout the planet. This then becomes a chain effect that can decide the temperature of oceans, the variance of temperature from one side of the planet to the other could be a setback for life.Tidal heating experienced by planets in the habitable zone of red dwarfs may cause them to be "baked out" and become "tidal Venuses."
STILL if red dwarf stars count as 75%, the stars have a longer life (so more time for life to develop) and of the 100 billion or so in our galaxy roughly 60 billion of them are deemed habitable, perhaps our search for life should be expanded to include more red dwarf stars.
Proxima Centauri, the Sun’s closest star or even Barnard’s star are samples, but red dwarf stars cannot always be seen by the unaided eye. Unfortunately their visual magnitude is not what it would need to be.
Should we find life on one what should we expect? Smaller animals due to less or no oxygen which would be due to plants utilizing a different cycle (not producing O2); these plants would probably have long flexible leaves that do not snap based on being on the receiving side of infrared light and not ultraviolet. Animals would rely more on infrared vision. Due to the planet wide wind there would be a difference to their calls unless of course they lived underwater where they would be protected from the gales
Red Dwarf Star’s and their habitable planets have dominated Science Fiction since before Earth knew of such possibilities scientifically. In 1937 Olaf Stapleton had a novel called “Star Maker” in which he had a most interesting civilization from the plant life to the life that evolved; OR Superman where Krypton circled a red star known as Rao.
So should we look for life on Red dwarf Stars, I think so – especially if you consider the Law of Parsimony or even the Drake equation, the fact extremophiles exist – meaning we know based on them that life can exist nay even thrive in extreme conditions, add in the huge amount of red dwarf stars; based on math and logic, I’d say yes.