The third era in the evolution of the Universe. This era will begin about 10^15 years ABB (After the Big Bang), and end around 10^40 years ABB. The era will begin when the formation of new stars ceases because there is no longer enough free hydrogen gas. Even the long-lived red dwarf stars will gradually wink out, and the entire Universe will consist only of degenerate stars: black holes, neutron stars, and white dwarfs. At the beginning, the dominant form of energy will be the radiated remnant energy from neutron stars and white dwarfs, but they will eventually cool down and become quiet. Over such a long timescale, two-body interactions between stellar corpses will dominate; with each interaction, the light star will be flung from its parent galaxy while the massive star will lose momentum and fall from orbit into the maw of the massive black hole at the galactic core. Starting around 10^30 years ABB or so, proton decay begins to occur, and that source of energy dominates for a while. As the era ends, almost all the protons have decayed and most energy is captured by a relatively small number of very large black holes.
The preceding era will be the Stellar Era, and the succeeding era will be the Black Hole Era.