A star system 3,000 lightyears away is set to become visible to the naked eye this year, in an event that will see its apparent brightness increase by 5 times.
T Coronae Borealis, also known as T CrB, last brightened in 1946, and astronomers have predicted it could brighten again between now and September 2024.
This brightening event is known as a 'nova', which means 'new star' in Latin, so-called because it describes how a previously dim star can suddenly reach prominent naked-eye brightness in the sky.
What the T Coronae Borealis nova will look like
Star system T Coronae Borealis normally shines at a brightness of magnitude 10, which is the measurement astronomers use to describe the relative brightness of one celestial object (i.e. how bright its appears from Earth) compared to others.
On the magnitude scale, the higher the number, the dimmer the object. Sirius, the brightest star in the night sky, has a magnitude of -1.46, for example.
The full Moon has a magnitude of about -13.
T Coronae Borealis is expected to jump to magnitude 2 during the nova event, which would make it similar in brightness to the North Star, Polaris.
It could be visible to the naked eye for several days and potentially visible for over a week through binoculars.
It will then dim again and could remain so for another 80 years, making this a potential once-in-a-lifetime astronomical event.
How to see the T Coronae Borealis nova
Keep an eye on astronomy outlets and follow @NASAUniverse on Twitter over the coming weeks and months for news of the brightening T Coronae Borealis nova event.
The nova will appear in the constellation Corona Borealis, which can be quite a tricky constellation to spot.
It appears as a small semicircle near the constellations Boötes and Hercules.
Boötes can be found by locating the Plough star pattern in the sky. Follow the 'handle' of the Plough away from the asterism and you'll arrive at Boötes.
Then look to the left of Boötes and you'll see Corona Borealis.
You can use an astronomy and stargazing app to help you locate the constellation, too.
Start observing Corona Borealis now and get familiar with its position in the sky. Then when the nova appears, you'll be ready to spot it.
If you are an astrophotographer, you could begin a project to photograph the Corona Borealis constellation regularly over the coming months, then you'll have a record of the nova's appearance and changing brightness over time.
What is a nova?
A nova is not the same as a supernova.
A supernova occurs when a massive star explodes at the end of its life, having run out of fuel.
A nova, on the other hand, is the temporary brightening of a star before it fades again.
T Coronae Borealis is a binary star system, meaning it consists of two stars orbiting each other.
T Coronae Borealis consists of a white dwarf and a red giant. A white dwarf is the dense remnant of a star that has used up all its fuel.
As the red giant begins to increase in temperature and shed its outer layers into space, the dense white dwarf companion pulls in that stellar material.
This causes the white dwarf to heat up, producing the increased brightness that we see as a nova from Earth.
The T Coronae Borealis nova event could be a wonderful highlight of the 2024 astronomy calendar.
If you manage to observe or photograph the T Coronae Borealis nova, let us know by emailing us at contactus@skyatnightmagazine.com
