The protoplanet AB Aur b is formed in the star system AB Aurigae, which is only 2 million years old. It is removed from the Earth at 531 St. year in the direction of the constellation Auriga. AB Aur b is about 9 times as massive as Jupiter. It orbits its star at a distance of 13.9 billion km, which is 3 times the distance between the Sun and Neptune.
The formation of such a massive protoplanet remote from the star cannot be explained by the generally accepted core accretion model. It implies that the gas giant begins as a rocky core and then accumulates gas.
Astronomers believe that the formation of AB Aur b can be explained by a competing theory – the instability of the protoplanetary disk. This is a process in which a massive gaseous protoplanetary disk, as it cools, breaks up into one or more collapsing fragments of a planetary mass, in which exoworlds are formed.