Starwatch: a 2,600-year wait to see T Coronae Borealis explosion

We are still waiting for the star T Coronae Borealis (T CrB) to do its thing. First mentioned in April , the star experiences a thermonuclear detonation on its surface roughly every 80 years. This explosion will make the star visible without an aid for the first time since the 1940s.

The chart shows the view looking south-south-west from London at about 2300 BST. It marks the location to keep an eye on. When it erupts, T CrB is expected to reach the same brightness as Alphecca, the brightest star in the constellation of Corona Borealis, the northern crown.

The Astronomical League suggests making a sketch of the constellation now and another when the star erupts. Sketching the constellation now will also help you pinpoint the day that the light from the eruption arrives at Earth.

Of course, the actual explosion has already happened. The star is located about 2,600 light years away, so the light we are waiting for exploded away from the star about 2,600 years ago and has been travelling through space ever since. Now it has just weeks or even days to go before it completes its journey and we see it.

From Sydney, Australia, the constellation will appear at its highest, due north, at about 2100 AEST.