About this image

This is an artist's concept of the red dwarf star CHXR 73 (upper left) and its companion CHXR 73 B in the foreground (lower right) weighing in at 12 Jupiter masses. CHXR 73 B is one of the smallest companion objects ever seen around a normal star beyond our Sun.

Estimated to be 12 times the mass of Jupiter, the object is small enough to be a planet, but also large enough to be a brown dwarf, a failed star. The NASA Hubble Space Telescope discovery of this diminutive companion to a low-mass star is a dramatic reminder that astronomers do not have a consensus in deciding which objects orbiting other stars are truly planets.

CHXR 73 B is 19.5 billion miles from its red dwarf sun (roughly 200 times farther than Earth is from our Sun). The youthful, 2-million-year-old star is one-third the mass of our Sun and lies approximately 500 light-years away in the Chamaeleon I star-forming region in our Galaxy.

Artwork, Brown Dwarfs, Stars


Credit: NASA, ESA and G. Bacon (STScI)