Between now and September, a colossal explosion 3,000 light years from Earth will flare up in the night sky, providing amateur astronomers with a once-in-a-lifetime opportunity to view this space oddity.
The binary star system in the constellation Corona Borealis — “northern crown” — is usually too dim to view with the naked eye.
However, every 80 years or so, interactions between its two stars, which are engaged in a deadly embrace, cause a runaway nuclear explosion.
The light from the blast travels through space and seems to be a new star — as bright as the North Star, according to NASA — that has suddenly appeared in our night sky for a few days.
This will be at least the third time humans have experienced this phenomenon, which was discovered by Irish polymath John Birmingham in 1866 and resurfaced in 1946.
Sumner Starrfield, an astronomer at Arizona State University, told AFP that he was looking forward to seeing the nova’s “outburst”.
After all, he has been working on T Coronae Borealis—also known as the “Blaze Star”—on and off since the 1960s.
Starrfield is already rushing to complete a scientific study forecasting what scientists will discover about the recurrent nova when it appears in the following five months.
“I could be today… but I hope it’s not,” he said with a laugh.
The white dwarf and red giant
Starrfield noted that there are only about ten periodic novas in the Milky Way and nearby galaxies.
Normal novas explode “maybe every 100,000 years,” he stated.However, recurrent novas repeat their eruptions on a human timeline due to a unique interaction between their two stars.
A red giant is a dying star that has burned through its hydrogen and grown significantly, similar to our own Sun in about five billion years.
The other is a white dwarf, which is a later stage in a star’s demise when all of the atmosphere has been blown away and just the extremely dense core remains.
According to Starrfield, the size difference between T Coronae Borealis’ white dwarf and its red giant is so large that it takes 227 days for the latter to orbit the former.
The two are so close that the red giant’s expelled stuff accumulates near the white dwarf’s surface.
Starrfield added that once the white dwarf has accumulated nearly the mass of Earth, which takes about 80 years, it warms up enough to initiate a runaway thermonuclear reaction.
This results in a “big explosion and within a few seconds the temperature goes up 100-200 million degrees” Celsius, according to Joachim Krautter, a retired German astronomer who has researched the nova.
Krautter told AFP that the James Webb satellite telescope will be just one of many eyes watching the explosion of T Coronae Borealis once it begins.
However, advanced equipment is not required to witness this unusual event, which could occur at any time.
“You simply have to go out and look in the direction of the Corona Borealis,” he remarked.
Some lucky skygazers are already gearing themselves for the year’s largest astronomical event on Monday, when a rare total solar eclipse will occur across a portion of the United States.