Artist’s impression of the CD-35 2722 system

This illustration shows the system around the star CD-35 2722, with the newly found moon-like object to the right. The star –– the point source at the top –– has about half the mass of our Sun, and it is orbited by a brown dwarf, the reddish-brown object seen here in the foreground (bottom). The brown dwarf has about 37 times the mass of Jupiter: too massive to be a planet, but not massive enough to have sustained nuclear fusion like stars. This brown dwarf is, in turn, orbited by a newly discovered object at least as massive as Jupiter, seen to the right of this image. This new object, found with ESO’s Very Large Telescope (VLT), is difficult to label. It behaves like a moon in the sense that it orbits an object that orbits a star. But this ‘moon’ is massive enough to be a planet, and the object it orbits, a brown dwarf, is neither a planet nor a star.