It’s not often that a dark spot in space illuminates our planet, but that’s exactly what professional and amateur astronomers expect to happen in September, when a once-in-a-lifetime nova explosion 3,000 light-years from Earth lights up our night sky life. .
What is a nova explosion?
A nova explosion is a dramatic case of a star exploding as it interacts with another nearby star. It is one of many, repeated moments during the long, slow death of two neighboring stars in the same system.
Astronomers are waiting for the fiery explosion of T Coronae Borealis, also nicknamed “Blaze Star” and known to astronomers as “T CrB”.
The system contains two stars — a white dwarf and a red giant. A white dwarf is an incredibly dense remnant of a once larger star. It is as big as planet Earth but has the same mass as our Sun.
Its neighbor, the red giant, is in its last years of existence and is slowly being stripped of hydrogen by the gravitational force of the denser white dwarf.
This stellar “cannibalism” causes a tremendous build-up of pressure and heat that eventually triggers a huge thermonuclear explosion. However, the explosion does not completely destroy the stars, so this event repeats itself over time. It can take hundreds of thousands of years.
UT CrB this nova occurs roughly every 80 years—it’s like Halley’s Comet event every 76 years—so astronomers refer to T CrB as a “recurrent” nova.
They believe that previous eruptions of T CrB were observed as far back as December 1787 and even October 1217 AD.
Is a nova the same as a supernova?
No. A supernova is the final explosion that completely destroys the stars. In the event of a nova, the dwarf star remains intact, which is why nova events usually repeat.
Different nova events have different cycles ranging from a few years to hundreds of thousands of years.
What does the nova look like?
A nova explosion blasts stellar matter in a blinding light, but it won’t look like the star explosion you see in the movies — luckily, we’re too far away to see that level of detail.
To the naked eye, the nova will instead look like a new star has appeared in the sky. People with high-powered telescopes will be able to see the brightly colored luminosity of the nova in some detail.
Will we be able to see the nova without a telescope?
Yes! When T CrB explodes, its luminosity increases dramatically, making it visible to the naked eye for days.
The northern corona is a horseshoe-shaped curve of stars west of the constellation Hercules, ideally visible on clear nights.
To find the Northern Hemisphere, find the two brightest stars in the Northern Hemisphere: Arcturus and Vega. Following the line between the two stars will take you to the Northern Crown where T CrB lies.
The European Space Agency told DW that all telescopes are already pointing at T CrB and waiting to capture the event, but no images are available yet.
When will the nova be visible?
All signs point to a nova explosion in September 2024. But novae can be unpredictable, so astrophysicists say it’s hard to know exactly when a T CrB nova will occur.
Have nova events been seen in history?
A T CrB nova was last seen from Earth in 1946. The first recorded sighting of a T CrB nova is believed to be more than 800 years ago in 1217, when an abbot in the town of Ursberg, Germany, noted “a faint star which for a time shone with a great light .”
The abbot wrote that the light lasted for “many days” and was considered a “wonderful omen.” Other celestial events, such as comets, were considered bad omens.
Astronomers have recorded supernova events much further back in history. The first sighting of a supernova dates back nearly 2,000 years to 185 AD, when Chinese astronomers saw a strange “guest star” appear in the night sky for eight months.
Editing: Zulfikar Abbany
Sources:
NASA Astrophysics https://science.nasa.gov/astrophysics
NASA, Global Astronomers Await Rare Nova Explosion, June 2024 https://www.nasa.gov/centers-and-facilities/marshall/nasa-global-astronomers-await-rare-nova-explosion/
The recurring nova T CrB had previous eruptions observed nearby in December 1787 and October 1217 AD. Journal of the History of Astronomy, November 2023 https://doi.org/10.1177/00218286231200492