Rare ‘Blaze Star’ will be visible in the North Texas night sky

A possibly once-in-a-lifetime Blaze Star will be visible to the naked eye in the D-FW night sky sometime between now and September.

Despite its name, Blaze’s Star actually consists of two companion stars—a white dwarf and a red giant—in the constellation Corona Borealis, about 3,000 light-years away. This pair of stars is known to scientists as a binary system and is called T Coronae Borealis.

About every 80 years, T Coronae Borealis grows up to 1,700 times brighter, becoming as bright as the North Star, Polaris, said Phillip Anderson, director of the William B. Hanson Center for Space Sciences at the University of Texas at Austin. Dallas. This event is called a recurrent nova, of which about 10 are known in the Milky Way galaxy.

As a star like the Sun ages over billions of years and burns its hydrogen for fuel, it eventually becomes a very hot, dense remnant called a white dwarf. With its great gravitational pull, the white dwarf in T Coronae Borealis is extracting hydrogen from its nearby red giant, a large, relatively cool star nearing the end of its life.

“The white dwarf is building a hydrogen layer; it’s getting hotter and hotter,” Anderson said. “Eventually, it reaches a point where hydrogen fusion starts as an explosion.”

The celestial explosion emits a brilliant flash of light that becomes visible to us as a twinkling star. This cycle continues many times over the lifetime of the star system, which makes it different from a supernova, a massive explosion that results in the death of a star.

The first eyewitness record of the Blaze Star was in 1217 by a German monk who described it as “a faint star that for a time shone with great light,” according to NASA. Other phenomena observed from Earth were in 1787 and 1866, with the last in 1946.

By comparing the star system’s current brightness with that observed in 1946 and 1866, Anderson said, scientists predict that T Coronae Borealis will shine brightly sometime in the next two months.

North Texans will be able to see T Coronae Borealis at night by finding Corona Borealis, which lies between the constellations Hercules and Boötes. Anderson recommends using a stargazing app like Star Walk for guidance.

“What I would suggest is to go out at night every now and then and get used to finding Boötes, Hercules, Corona Borealis and Alphecca,” he said. “Find where you expect to see the star, and then one day, you go, ‘Oh look, there’s a star I haven’t seen before.’

Alternatively, you can try looking at the sky about 15 degrees above the horizon just after sunset.

After T Coronae Borealis erupts, the glow will be brief, about less than a week. But it will give scientists a perfect opportunity to better understand repeated novae, Anderson said.

“We are looking at stellar evolution. … To be able to watch this in real time, in our lifetime, is amazing.”

Miriam Fauzia is a science reporting associate at The Dallas Morning News. Her fellowship is supported by the University of Texas at Dallas. The news makes all editorial decisions.