Seven of them were successful, and analyzed the sun at ultraviolet and X-ray wavelengths and photographed the super-hot corona, among other achievements.

And whenever you make a measurement of the mass when it is a neutron star when you see the x-ray pulsations, you almost always find 4 that it is very close to 1.4 times the mass of the sun.

TRAPPIST-1 emits about the same amount of X-ray and ultraviolet radiation as the Sun does, which could chew away at any protective atmospheres the planets might have.