What is the specific astronomical object formed when a protostar fails to meet the $0.08 M_{\odot}$ ignition threshold?

Answer

Brown dwarf

When a protostar falls short of the mass required to initiate self-sustaining hydrogen fusion, it becomes a brown dwarf. This object occupies a middle ground between the largest planets and the smallest true stars.

What is the specific astronomical object formed when a protostar fails to meet the $0.08 M_{\odot}$ ignition threshold?
astronomystarprotostarstellar evolutionmass