(Imaginary Picture of GJ9827 c: Ryusuke Kuroki, Fuka Takagi & Yosuke A. Yamashiki)
GJ9827 (also known as K2-135) is a K6 type star (with a surface temperature of 4255K, a mass and radius about 0.7 times that of our Sun) about 100 light-years away from the Earth. It was discovered by the transit method during the K2 mission (the second mission of the Kepler Space Telescope). Scientists found three Super-Earths (planets with a mass and radius several times that of the Earth) orbiting the star, reported in the Astronomical Journal published in February 2018. These three Super-Earths (GJ9827b, GJ9827c, GJ9827d in order of closeness to the host star) have radii of 1.62 times, 1.27 times, and 2.07 times the Earth, and their orbits around the host star are 1.2 days, 3.6 days, and 6.2 days, respectively.
The planet is a suitable candidate for more detailed observation of its planetary atmosphere using the James Web Space Telescope (JWST), which will be launched in a few years. These observations of Super-Earth atmospheres are said to be the key to understanding the atmospheric and internal structure of these types of planets, which are located at the boundary between the terrestrial planets (rocky planets) and gaseous planets, such as Jupiter. This is why the GJ9827 planetary system is so promising.
1.) Planet GJ 9827 c