Webb Finds the Lightest 'Failed Stars'

Jupiter is sometimes referred to as a ‘failed star.’ This is misleading, since it formed from the same disk of leftover material surrounding the young Sun that the other planets did.

An actual failed star forms the same way a real star does – from the direct gravitational collapse of a cold, dense cloud of gas and dust. If it’s not massive enough, though, its core never reaches the temperatures and pressures high enough to initiate nuclear fusion.

Such a ‘failed star’ is referred to as a brown dwarf.

The James Webb Space Telescope recently pointed at the star-forming cloud IC 348, located about 1000 light-years away in the Perseus Molecular Cloud, to search for brown dwarfs among the population of newly-formed stars. It found the smallest ‘failed stars’ yet discovered, some with just twice the mass of Jupiter.