A super-Earth planet was discovered near the habitable zone of a red dwarf star just 37 light years from Earth. This is the first discovery made by the new instrument on the Subaru Telescope, and offers an opportunity to investigate the possibility of life on planets around nearby stars. With such a successful first result, we can expect the Subaru telescope to discover more, potentially even better, candidates for habitable planets around red dwarfs.
Red dwarfs, stars smaller than the Sun, make up three-quarters of the stars in the Milky Way galaxy and are abundant in the vicinity of the Sun. As such, they are important targets in the search for nearby exoplanets and extraterrestrial life. But red dwarfs are cool and don’t emit much visible light compared to other types of stars, making them difficult to study.
In the infrared wavelength range, red dwarfs are brighter. Therefore, the Center for Astrobiology in Japan developed an infrared observation instrument mounted on the Subaru Telescope to search for signs of planets around red dwarf stars. The instrument is called an IRD for infrared doppler, the observation method used in this search.
The first fruits of this search are signs of a super-Earth four times the size of Earth orbiting the star Ross 508, located 37 light-years away in the Serpentine constellation. This planet, Ross 508 b, has a year of just 11 Earth days, and is located at the inner edge of the habitable zone around its host star. Interestingly, there are indications that the orbit is elliptical, which would mean that for part of the orbit the planet would be in the habitable zone, a region where conditions would be favorable for the existence of liquid water on the planet’s surface. Whether there is actually water or life is a matter for further study.
That the very first planet discovered by this new method happened to be so close to the habitable zone seems too good to be true, and bodes well for future discoveries. Bunei Sato, professor at Tokyo Institute of Technology and principal investigator of this search comments: “It has been 14 years since the development of the IRD began. We have continued our development and research with the hope of finding the exact planet as Ross 508 b.”
Materials is provided National Institutes of Natural Sciences. Note: Content can be edited for style and length.