US space agency NASA says a massive starburst is expected to light up the night sky later this year. NASA describes it as a “once in a lifetime” event.
The event is known as a nova. It occurs when changes in a star cause it to release a large amount of energy and it becomes very bright. This activity is only temporary and such stars usually return to their normal state after experiencing a nova event.
astronomer have predicted that the nova is likely to occur by September 2024. The expected event will involve a system of two stars – called a binary system – in constellation Corona Borealis, also known as the Northern Crown. This constellation is about 3000 light years from Earth. A light year is the distance light travels in one year – about 9.5 trillion kilometers.
The binary system is called T Coronae Borealis. It contains two gravitationally bound stars – a white dwarf and a red giant.
NASA describes a white dwarf as the remnant of an Earth-sized star that died. A white dwarf forms when the star burns through all of its central nuclear fuel and loses its outer layers.
A red giant is formed when a star releases large amounts of hydrogen at its center. This loss of energy causes the star to begin to collapse. But the process also increases the temperature and pressure of the red giant, leading to new releases of energy that can affect nearby objects.
Astronomers say the release of hydrogen from a red giant in a binary system causes a huge build-up of pressure and heat in the white dwarf. Over time, such an accretion could cause a “thermonuclear explosion” large enough to explode the material the white dwarf had collected.
This process differs from a supernova. NASA describes a supernova as an “extremely bright, super-powerful explosion of a star.” The main difference is that a supernova is the final destruction that occurs at the end of a given star’s life. In a nova, the white dwarf remains active after the event.
Scientists believe that novae recur on average every 80 years. NASA notes that nova events can continue to occur “for tens of hundreds or thousands of years.” That’s why the space agency called the upcoming nova a “once-in-a-lifetime event.”
Scientists say the nova explosion will be so bright that people should be able to see the resulting light without telescopes or other special equipment. Bright light can make it look like a new star has formed in the sky.
It will be at least the third time humans have witnessed a nova, reports the French news agency AFP. The event was first discovered by Irish astronomer John Birmingham in 1866 and then reappeared in 1946.
Sumner Starrfield is a professor of astrophysics at Arizona State University. He told AFP it was too much excited to see the nova event. He has studied the T Coronae Borealis star system at various times since the 1960s.
Starrfield is currently working on a scientific paper to predict what astronomers will learn about the recurring renewal each time it occurs. “It might be today… but I hope not,” he joked.
Rebekah Hounsell is a research scientist specializing in nova events at NASA’s Goddard Space Flight Center in Maryland. She said interest in the event could “create a lot of … astronomers out there.” She hopes that this can give young people “a spaceship events that they can observe for themselves, ask their own questions and collect their own data.”
She added that the nova event could even be useful for “feeding the next generation of scientists”.
I’m Bryan Lynn.
Bryan Lynn wrote this story for VOA Learning English, based on reports from
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The words in this story
astronomer – n. a person who studies the stars and planets
constellation – n. a group of stars that forms a particular shape in the sky and is given a name
excited – n. feels very happy and enthusiastic
spaceship – adj. pertaining to the entire universe