Astronomers, using the TESS space telescope, have discovered two exoplanets, two super-Earths, within the habitable zone of a nearby star. Both exoplanets are slightly larger than our planet and both orbit the same red dwarf star.
Transiting Exoplanet Survey Satellite (TESS) from NASA identified the two planets during their transit in front of their parent star, TOI-2095, which is located approximately 137 light-years from our Solar System. This transit caused a decrease in the star’s brightness, and the analysis of these brightness dips revealed the presence of the planets, along with some of their characteristics.
TOI-2095b and TOI-2095c
Red dwarfs like TOI-2095 are part of the largest family of stars in the universe. Despite being cooler than the Sun, these stars experience violent outbursts of ultraviolet and X-ray radiation during their youth. Such intense radiation could potentially strip away the atmospheres of planets in relatively close orbits. As a result, scientists are uncertain whether planets in the habitable zone of a red dwarf are actually conducive to Earth-like life.
The closest planet to the red dwarf, TOI-2095b, is approximately one-tenth of the average distance between Earth and the Sun. This exoplanet, which is 1.39 times larger than our planet but has up to 4.1 times its mass, takes around 17.7 Earth days to complete one orbit around the star.
The second planet, TOI-2095c, is a bit farther away. It takes 28.2 Earth days to orbit the red dwarf. This exoplanet has a diameter about 1.33 times that of Earth and has up to 7.5 times the mass of our planet. Planets likely have surface temperatures ranging between 24°C and 74°C.
The Discovery
Team behind the discovery, led by astronomer Felipe Murgas from the University of La Laguna in Spain, (ref.) emphasized that the relatively long orbital periods of these two planets could provide crucial data. This data can help shed light on the processes that shape the composition of small planets orbiting red dwarfs, as detailed in the preliminary study on ArXiv (ref.).
The discovery of these two super-Earths further demonstrates the power of the TESS mission. Since its launch in April 2018, the exoplanet hunter has found approximately 330 confirmed alien worlds, along with over 6,400 candidates awaiting further studies or follow-up analysis.
The team now plans to follow up on the discovery by conducting precise radial velocity measurements. By utilizing these measurements, they can better estimate the masses of TOI-2095b and TOI-2095c, which would allow for a more accurate determination of the planets’ densities. This could help astronomers determine whether these two planets managed to retain their atmospheres.