Rare T Coronae Borealis nova explosion this September: What it is and how to see it | Technology News
The world is set to witness a rare nova explosion, a powerful surge in the brightness of a star that is usually caused by a thermonuclear explosion on the surface of a dwarf star.
T Coronae Borealis, also known as the Blaze Star or T CrB, is a binary system on the Northern Crown. This system has the remnant of a dead star as big as Earth, with a mass similar to the Sun. The T CrB is essentially the white dwarf and a red giant planet that orbit each other.
According to Nasa, the T CrB experiences a thermonuclear detonation on its surface almost every 80 years. It was last seen from Earth in 1946. At present, The T CrB has been showing a similar behaviour witnessed in the run up to the massive eruption in 1946. Nasa believes that if the behaviour continues, the nova event could likely take place by September 2024.
In its previous sighting, astronomers observed that in 1945, year before the explosion, the star’s luminosity dimmed. Recently, a similar phenomenon has been observed, leading astronomers to anticipate an explosion anytime between now and September. The exact time of the explosion cannot be predicted. However, astronomers say it could occur today, tomorrow, next week, or even sometime next year. However, the chances are high that it will happen sometime between now and September.
What is T Coronae Borealis
Some 3,000 light-years away from Earth, the T Coronae Borealis dwells in the constellation known as Coronae Borealis. Owing to its periodic explosive nature, this star system has been closely observed by astronomers on Earth for years. They have classified it as a recurring nova due to its cyclic eruptions. It is a binary system, meaning the T CrB consists of two stars – a red giant and a white dwarf. As both these stars orbit each other they create the perfect conditions for the recurring nova events.
According to Nasa, the first recorded sighting of T CrB was over 800 years ago in 1217 when Abbot Buchard from Ursberg, Germany observed it. He noted it as a faint star that for a time shone with great light.
How do the nova explosions on T CrB occur?
The nova explosions on T CrB occur when the red giant expands and fills its Roche lobe (a teardrop-shaped region where the material is bound to the star by gravity). Following this the matter from the red giant crosses the gravitational balance point. At the same time hydrogen gas accumulates on the white dwarf’s surface and there is an increase in pressure and temperature at the base of this hydrogen layer. When these critical conditions combine, there is a spontaneous thermonuclear fusion resulting in an explosion that violently ejects the accumulated gas. This event occurs nearly every 80 years for T CrB.
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It needs to be noted that this is not a supernova, which is said to be the final massive explosion that destroys dying stars. During a nova event, the dwarf star is intact, and relays its accumulated material into space in an enormous blinding flash. This cycle repeats itself over time and can even occur for hundreds or thousands of years. When compared to novae, supernovae are significantly brighter and can be seen across vast cosmic distances.
During the nova event, T CrB throws shells of gas expanding away from the system and it is visible in deep astronomical images. T CrB reaches a brightness of magnitude 2.5 which is comparable to North Star (Polaris). Although it may not be as bright as some may expect, yet it is visible to the naked eye.
The next T Coronae Borealis event is a much-awaited event for the scientific community worldwide. Considering the significant advancement in technology since 1946, the upcoming event will likely make it the most thoroughly studied nova in human history.
How to spot T Coronae Borealis
To spot T CrB, one should ideally look towards the Northern Crown, which lies to the west of the Hercules constellation. Stargazers should seek a straight line passing through Arcturus and Vega, the brightest stars in the northern hemisphere, as this will lead them to Coronae Borealis. The explosion will likely be brief, and once it occurs, it will be visible to the naked eye for nearly a week.
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T Coronae Borealis will be primarily visible from countries in the Northern Hemisphere, including the US, Canada, and Mexico. In Europe, it can be seen in the UK, Germany, France, Spain, and Italy, while in Asia, it will be visible in India, China, Japan, South Korea, and others. Countries near the equator will have a limited view.
The T Coronae Borealis poses no threat to Earth, especially due to its distance spanning thousands of light years. This celestial event poses a unique opportunity for astronomers to closely examine the recurring nova events. T CrB’s predictable behaviour makes it invaluable in ongoing research into stellar evolution and the phenomena of explosive star formation.
