Astronomers are waiting for the zombie star to rise again

The long-dead star is set to go supernova soon, making it visible in the evening sky for a short time. it’s not

Every 80 years or so, the T Coronae Borealis star system — or T CrB for short — violently explodes, reigniting a long-dead star.

Earlier this year there were strong indications that T CrB had been ready to create this new visible star for a few days. This has not happened yet, but history indicates that it is only a matter of time.

Accurate predictions can be difficult when you’re talking about something happening 3,000 light-years away.

Red giant + white dwarf

The T CrB system is actually two stars. More than half of the stars we see in the night sky have one or more partners.

It is made up of a red giant, a late-life star that has inflated to its original size hundreds of times. Our sun will be there in about 5 billion years.

The other is a white dwarf, which is an incredibly dense, Earth-sized remnant of a dead star. Since 1946, this dark, dense white dwarf has been sucking stellar material from its red giant partner, like a vampire.

But a dead star can only draw so much of its companion’s life force. Once it reaches a critical mass, the surface layers explode in an event called a nova, making it visible to the naked eye for a few days.

Records of previous T CrB nova events go back more than 800 years. In 1217, a man named Burchard wrote of observing “a faint star that shone for a time with great light” from his home in Auersberg, Germany.

Amateur astronomers and professional scientists alike are eagerly awaiting this event.

“Nova events are usually so faint and distant that it is difficult to clearly determine where the explosive energy is focused,” explained Dr. Elizabeth Hayes, head of NASA Goddard’s Astroparticle Physics Laboratory. “This will be really close, with a lot of eyes on it, studying different wavelengths, and hopefully it will give us the data to start unlocking the specific structure and processes involved. We can’t wait until we get the full picture of what’s going on.”

How and when to find T CrB

T CrB will be visible to the naked eye, but it is not clear when it could be days, weeks or even months.

Once visible, T CrB, also known as a “flare star,” will appear between the bright stars Vega and Arcturus in the western sky after sunset. If this happens in the next few weeks, Venus can also help provide a guide.

We don’t know exactly when this will happen, but it will likely happen soon.

Nova or supernova?

This would be a nova, not a supernova.

Unlike supernovas, which destroy a star, novae only eject accreted layers of stellar material and can happen over and over again. Supernovae shine for a few days at most, while remarkably supernovae shine for up to months.

Recent changes in Betelgeuse, a giant red star in the Orion constellation, have fueled speculation that it may go supernova “soon.” A Paper 2023 He studied the star’s brightness and dimness and concluded that “a supernova explosion is expected within dozens of years.”