French astronomer hopes to observe exploding star - and you can too
The nova in the northern sky will be visible to the naked eye for a week
The T CrB nova will be visible for a week after the explosion
Jakob Weyde/Shutterstock
A French astronomer hopes to catch the moment that a star in the northern sky explodes in the last week of September. Afterwards, the star's nova will remain visible to the naked eye for a week.
T Coronae Borealis (T CrB), or the ‘Blaze Star’, which was first observed 800 years ago, explodes approximately every 80 years. The last time was in 1946.
The star is part of a binary system in a nova some 3,000 light-years from Earth.
Astronomers around the world are expecting the star, which is in the Northern Crown constellation, to explode again in September 2024, having detected a decrease in its luminosity since March 2023.
The explosion will see the nova increase its luminosity 1,000-fold, shining brighter than the North Star for a week, then fading again, marking the end of its 80-year cycle.
The explosion is forecast to occur before the end of September.
A (probably) once-in-a lifetime chance
A French astronomer is hoping to observe the explosion with France’s NenuFAR radio telescope - the fourth largest in the world in terms of surface area.
“It has never been observed at low radio frequencies. So if we detect it with NenuFAR, it will be a first!’, Philippe Zarka, director of research at the French National Centre for Scientific Research (CNRS) told FranceInfo.
“Previous observations of this nova have shown that the increase in luminosity that makes it a thousand times brighter lasts less than a day, and the subsequent decrease makes it return to its previous state over a period of a few weeks.”
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How can I see the star?
T CrB should be visible to the naked eye on clear nights across France.
To spot the it, locate Arcturus and Vega, the two brightest stars in the Northern Hemisphere.
The Corona Borealis constellation is between them, slightly closer to Arcturus.
If the star has already exploded, the nova will shine bright - almost as bright as Vega - otherwise it will be invisible.
However, if you are very lucky, you could witness the moment that the nova suddenly appears as the star explodes.
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Why does the star do this?
T CrB, is actually made up of two stars: a small, earth-size white dwarf and a large, sparse red giant.
“They revolve around each other. Gravity deforms the red giant, causing it to project mass onto the white dwarf. This accumulation of mass eventually leads to an explosion in the upper layers of the dwarf,” said Dr Zarka.
The stars in the nova are relatively close to the earth, and the short cycle of the explosions make it a unique opportunity to learn more about how stars work.
“We're going to find out more about it,” said Dr Zarka. “How much energy does this phenomenon produce? How destructive is it? What is produced at frequencies and wavelengths that were not observed 80 years ago? What is produced in radio? And by what mechanisms?”
Nasa astronomers are also observing the phenomenon, with nova specialist Dr. Rebekah Hounsell telling nasa.gouv that she hopes the event will “create a lot of new astronomers”.
