The Quiet Lives of Very Low-Mass Stars and Brown Dwarfs

Abstract

As we go down in mass along the main sequence, a regime is reached where the stars become fully convective. This occurs around 0. 3 Mq and it defines the upper limit of the mass range of the very-low mass (VLM) stars. The fully convective nature of these objects persists down to planetary masses, e. g. Jupiter. Such stars have spectral types later than dM3 and effective temperatures below about 3500 K. For objects below ≈ 0. 08 M⊙, the central temperature remains too low to sustain sufficiently vigorous nuclear burning to achieve an equilibrium configuration on the main sequence. These objects, known as brown dwarfs (BDs), loose their initial heat content as they cool rapidly to degenerate configurations.