More information on the new trappist-1 system!
TRAPPIST-1, is an ultra-cool red dwarf star located some 39 light years away. TRAPPIST-1 is one of the smallest and coolest red dwarf stars known. In cosmic terms, it's not much larger than the planet Jupiter and it's about 2,000 times dimmer than our sun. Yet that doesn't stop this system from being one of the strangest ever discovered. Orbiting TRAPPIST-1 are seven Earth-sized planets, three of which orbit in the habitable zone and, as the astronomers have said, all seven could potentially be habitable given certain conditions.
The research team, which as led by Michaël Gillon of the University of Liège in Belgium, originally studied the star using the TRAnsiting Planets and PlanetesImals Small Telescope (TRAPPIST), an instrument at the La Silla Observatory in Chile. Using TRAPPIST, the team detected three exoplanets around the star, TRAPPIST-1b, TRAPPIST-1c and TRAPPIST-1d, in May 2016. Yet follow up observations seemed to indicate that the transit of TRAPPIST-1d was caused by more than one planet. NASA's Spitzer Space Telescope cleared this up and revealed that the signal of TRAPPIST-1d was caused by three different planets. Spitzer also confirmed the existence of an additional two more planets, adding up to seven in total.
These seven planets are all roughly the same size and mass as Earth. The smallest is about 75% as massive as Earth, while the largest is about 10% more massive. Each of the seven planets orbit quite tightly to their star. Each of them orbits closer to TRAPPIST-1 than Mercury does to our sun. Yet due to the much smaller size of TRAPPIST-1, this is actually a good thing, being that the habitable zone is located much closer to the star. The orbital periods of the six inner planets range from 1.5 days to 12.4 days. The farthest planet completes one orbit ever 20 days.
The discovery of this system is a milestone in the search for habitable worlds beyond the solar system and the search for life. I'm going to do detailed posts on each planet in the Trappist-1 system.