M-Dwarf Stars, Lesser Understood Cousins Of The Sun That Could Host Habitable Planets

Yellow dwarf stars like the sun have the ability to support life; this is a widely known fact. However, there is another often ignored star type whose planetary system can also be ideal for detecting habitable exoplanets. Called M-dwarf stars, these celestial bodies are actually red dwarf stars that are quite a common occurrence in the Universe.

As per a report, it would be easier for astronomers to discover a passing planet in front of the comparatively dim and small M-dwarf stars. If orbiting planets group closely near an M-dwarf, then they can fall in a zone where it is possible to have surface liquid water and, therefore, life too. However, the habitable zone of M-dwarf stars is poorly understood. Scientists are not very clear about the necessary distance that the planets orbiting a M-dwarf star should have for liquid water to prevail on the surface.

According to researchers, the planets could be tidally locked because some of them orbit too close to the M-dwarf. "They're always facing the same side of the star, just like the moon does around the Earth," said Ravi Kumar Kopparapu, research scientist at NASA. A tidally locked position would imply that though the climate for life on the planet could be potentially stabilized, the side facing the parent star could be extremely hot whereas the other side would be very cold.

Kopparapu feels that scientists need to know more about the habitable zones around M-dwarfs due to the upcoming missions in the near future that will revolve around exoplanet research. NASA's Transiting Exoplanet Survey Satellite (TESS) is supposed to be launched next year to investigate more planets. Tess will also serve as a guide for the James Webb Space Telescope in 2018, the latter incidentally will offer high resolution images and data that can help scientists throw light on the atmospheric gases of a planet that orbits an M-dwarf star. The information provided by the future space telescope could also reveal details like the temperature of a planet and its potential for supporting the right conditions for the existence of life.