Pulsars, or rapidly-spinning neutron stars, have been observed suddenly change how fast they spin. Typically, the pulsars we’ve seen do this are isolated—what happens if they have a stellar companion?
This paper reports the results of a cosmological simulation, and how smooth accretion and mergers affect three important aspects of galaxy formation: stellar mass growth, size increase, and morphology changes.
Those of us who love astrobiology get really worked up about the lack of Earth-sized exoplanets found at Earth-like distances from their stars. All we want, we who hope for lots of extraterrestrial life, is a bunch of Earth-like planets doing Earth-like things so we can feel better about the odds for lots of Earth-like life in the universe.
Once thought to be the main mechanism by which galaxies feed their star formation; the authors of this paper find that minor mergers cannot account for the observed star formation rates of galaxies.
What might be causing the accretion rates in newly formed stars to remain so high?
The authors report the discovery of perhaps the faintest black hole x-ray binary. But this conclusion is limited by the uncertainty in the distance to the object.