Just 37 light-years from Earth, a super-Earth has been detected in the “habitable” zone of a red dwarf star. This is the first discovery made by a completely new instrument on the Subaru Telescope of Japan located in Hawaii (USA).
This event offers an opportunity to consider the possibility of life on planets around stars near our Solar System.
Scientists named this super-Earth Ross 508. According to NASA data, Ross 508 orbits an M-type red dwarf star. Its mass is four times that of Earth.
The green zone represents the habitable zone where liquid water could exist on the planet’s surface. Planetary orbits are shown as a blue line. Ross 508 b glides past the inner edge of the habitable zone (solid line), possibly crossing the habitable zone for part of the orbit (dashed line). Source: Japan Center for Astrobiology
According to scientists, red dwarfs are easier to see at infrared wavelengths. In search of evidence of planets surrounding red dwarf stars, the Center for Astrobiology in Japan created an infrared observatory mounted on top of the Subaru Telescope – it’s a Doppler instrument. infrared (IRD) on Subaru’s 8.2-meter telescope – conducts Ross 508’s radial velocity (RV) measurements.
The first result of this search is a sign of a super-Earth four times the mass of Earth, orbiting the red dwarf star Ross 508, located 37 light-years away, in the constellation Serpens.
This planet, Ross 508 b, has a year of just 10.8 Earth days and lies at the inner edge of the “habitable zone” (Goldilocks) around its host star. Despite being quite close to the Ross 508 dwarf star, because the red dwarf is small and quite cool, the “habitable zone” of the planet Ross 508 b is also closer than the “habitable zone” of Earth – our sun.
The Japanese Subaru Telescope.
Interestingly, the scientists initially noticed that there are indications that the orbit is elliptical, meaning that for part of the orbit, the planet Ross 508 b will be in the habitable zone – regions where the conditions are right for liquid water to exist on the planet’s surface. Whether there is really water or life are questions that need further study.
It will also be an important target for future observations to study the possibility of life around low-mass stars like the M dwarf it orbits.
The exact orbital eccentricity of Ross 508 b is unknown. Further studies of this could provide important information about the planet’s origins.
CHARACTERISTICS OF THE RED STAR
The parent star Ross 508 has a radius of about 0.21 solar radii and a mass approximately 0.18 solar masses, giving it a density of 26.5 g/cm3.
The parent star Ross 508 has a radius of about 0.21 that of the Sun.
Red dwarfs make up three-quarters of the stars in our Milky Way galaxy and exist in large numbers in the vicinity of the Solar System, making them an excellent target for searching for exoplanets in the vicinity our close.
Three-quarters of the stars in the Milky Way are red dwarfs, smaller than the Sun and abundant in the Sun’s vicinity. They are therefore an important target in the hunt for nearby extrasolar planets and extraterrestrial life. Red dwarfs are cooler than other types of stars and produce less visible light, which makes them difficult to study.
Bun’ei Sato, Professor at Tokyo Institute of Technology (Japan) and principal investigator on this search commented: “It’s been 14 years since IRD started developing. We have continued to develop it. developed and studied in hopes of finding a planet exactly like Ross 508. Our discovery demonstrates that searching for near-infrared RVs can play an important role in finding a low-mass planet around cool M dwarfs like Ross 508”.
With such a promising initial discovery, we can expect the Subaru Telescope to find more, maybe even better, candidates for habitable planets near the red dwarf future.
The term “Super-Earth” refers to planets with a mass greater than Earth but not exceeding the mass of Neptune. Although the term “Super-Earth” refers only to the mass of the planet, it is also used by astronomers to describe planets larger than Earth but smaller than so-called “mini-Neptunes”. (with a radius of two to four Earths).
Source: Scitechdaily, NASA/Exoplanets