A group of astrophysicists at the U of T have recently discovered a mysterious object, named ROXs 42Bb, located 500 light years away from the Sun. Despite having 7 years’ worth of information on the object, ranging from its mass to its molecular composition, scientists have been unable to classify it as either a planet or a failed star (also known as a “brown dwarf”).

According to U of T post-doctoral fellow Thayne Currie, classifying the object is difficult because of two facts: on one hand, the object is 9 times the mass of Jupiter, but still below that of a brown dwarf; conversely, it is located at a  distance 30 times greater from its host star than Jupiter is from the Sun.

This represents an unknown area on the spectrum of planets and brown dwarfs. Objects with a planet-to-star mass ratio 10 times that of Jupiter, and within 15 times its distance from the Sun, are labelled planets. Those located from their host star at distances 50 times greater than that between Jupiter and the Sun are considered to be brown dwarfs. The mysterious ROXs 42Bb is beginning to fill the spectrum between these two classifications, and Currie believes that this will “spur new research in planet and star formation theories”