NASA-International Space Station

The object, known as GJ 758 B, might be either a large planet or a "failed star," also known as a brown dwarf. The faint companion to the Sun-like star GJ 758 is expected to be 10 to 40 times as massive as Jupiter and is a "near neighbor" in our Milky Way galaxy, hovering a mere 300 trillion miles from Earth.

Also known as HiCIAO, it is part of a new generation of instruments particularly made to discover faint objects near a bright star by masking its far more intense light. They also employed a method known as angular differential imaging to capture the images.

"It's astonishing how quickly this instrument has come online and burst into the forefront," said Marc Kuchner, an exoplanet scientist at the NASA Goddard Space Flight Center in Greenbelt, Md., who was not concerned in the work.

"It looks very promising," said Christian Thalmann, one of the team's guide scientists. If it should turn out to be a second companion, he said, that would make both B and C more probable to be young planets rather than old brown dwarfs, because two brown dwarfs in such close propinquity would not remain steady for such a long period of time.