SLD
Contributor
We’re Overdue for a Once-in-a-Lifetime Naked-Eye Nova
The famous exploding star T Coronae Borealis is due to detonate any day now, but it’s running a little late
T Corona Borealis was slated to go nova before September, but still has not done so. It is a red giant and white dwarf binary where the white dwarf is sucking off material from the expanding red giant. Every 80 years or so, after sufficient hydrogen builds up to start fusion again, it goes Nova having definitely been observed in 1866 and 1946, and possibly in 1786. It started dimming about a year and a half ago which it also did almost 80 years ago.
So why hasn’t it? More importantly what does the delay portend? If the buildup of hydrogen on the white dwarf is continuing could it exceed the Chandrasekhar limit of 1.4 solar masses and then cause a Type 1A supernova? Doubtful perhaps, but how else do Type 1A’s ever occur if the nova process always blows off enough to stop it from ever getting past the Chandrasekhar limit?
I’m a little skeptical because the dimming seems to have happened earlier this time than in in 1946 when it was 80 years from its previous explosion. It’s only been 78 years since 1946. But the hydrogen accumulation may not be proceeding at the same rate as before. We’re definitely overdue for a supernova in our galaxy. If it only goes nova it won’t be particularly spectacular, just brightening to the level of the North Star, Polaris.
Hopefully it will not go for the next month or so while it isn’t very visible in our sky. Right now it’s still up in the northwestern sky for about three hours after sunset. But by mid next month it won’t be much to see until it shows up in the early morning a month later. Look for the northern crown above Arcturus and it can be seen with binoculars or a decent telescope, but hard to pinpoint. Here’s a photo of it.
