Once Monday's eclipse fever has passed, there is an extraordinary upcoming celestial event to look forward to. Corona Borealis, or the Northern Crown, is a constellation located between Hercules and Boötes in the night sky. T Coronae Borealis, or T CrB, is a binary star system within the constellation consisting of a red giant and a white dwarf. And once every eighty years or so, it explodes.
From NASA:
This recurring nova is only one of five in our galaxy. This happens because T CrB is a binary system with a white dwarf and red giant. The stars are close enough that as the red giant becomes unstable from its increasing temperature and pressure and begins ejecting its outer layers, the white dwarf collects that matter onto its surface. The shallow dense atmosphere of the white dwarf eventually heats enough to cause a runaway thermonuclear reaction – which produces the nova we see from Earth.
Novae from Corona Borealis were observed in 1866 and 1946, but NASA scientists believe it will occur again this year, sometime between now and September. Normally not visible to the naked eye, the star system could appear as bright as Polaris, the North Star, for several days. It may be visible with binoculars for up to a week, but then it will dim again for another eighty years.
This video from the Houston Astronomical Society features a talk by a very talented amateur astronomer about recurrent novae, and T CrB in particular.
via phys.org
