It’s big. It’s bright. And it’s doomed.
Antares is one of the most impressive stars in the galaxy. It’s at least 15 times as massive as the Sun, hundreds of times wider, and tens of thousands of times brighter. But that flashiness comes at a price. The star’s lifetime will be measured in millions of years versus billions of years for more sedate stars like the Sun.
When that lifetime is up, the star’s core will collapse, while its outer layers will blast into space as a supernova. The blast will push a mixture of chemical elements out into the galaxy — elements created in the star’s core during its short lifetime, or in the surrounding layers of gas during the explosion.
The collapsed core will most likely form a neutron star — a ball a couple of times the mass of the Sun but only a few miles in diameter. Most young neutron stars spin rapidly, beaming out pulses of energy, so they’re also known as pulsars. And they generate magnetic fields that can be millions of times stronger than Earth’s. That gives them yet another designation: magnetars.
Astronomers don’t know all the signs that herald an impending supernova, so they can’t be sure just when Antares will explode. All they know for sure is that it’s likely to happen within the next million years or so — and it could happen as early as tonight.
Look for bright orange Antares rising to the right of the Moon around 11 o’clock, and leading the Moon across the sky later on.