The seven-planet system, TRAPPIST-1, is 39 light-years from Earth in the constellation Aquarius. Follow-up observations of the system reveal that TRAPPIST-1h is about three-quarters the size of Earth and orbits its star in just under 19 days. The planet sits about 9.6 million kilometers from its star, which has only 8 percent of the mass of the sun. As a result, TRAPPIST-1h gets about as much starlight as the icy dwarf planet Ceres, in the asteroid belt, gets from the sun.
Such limited light makes the planet too cold (‒100° Celsius) to harbor liquid water and therefore life as we know it, the researchers report.