NASA: ‘Once-in-a-Lifetime’ Nova Eruption Could Happen Any Day

NASA has announced that a “once-in-a-lifetime” nova eruption, predicted to occur by September, will be visible to the human eye. This event involves T Coronae Borealis (T CrB), a star system that typically erupts every 80 years. The last visible eruption from Earth occurred in 1946.

Historical Context

Novae have fascinated astronomers for centuries. The term “nova” comes from the Latin word for “new,” as these events were historically thought to be new stars appearing in the sky. The study of novae has significantly advanced our understanding of stellar evolution and nuclear processes in stars.

The Science Behind T CrB

T CrB consists of a white dwarf and a red giant star orbiting each other. A white dwarf is a “dead” star that no longer undergoes nuclear fusion, while a red giant is a star that has exhausted the hydrogen in its core. The red giant’s hydrogen accumulates on the white dwarf, eventually leading to a thermonuclear explosion, or nova, approximately every 80 years.

When this nova occurs, it will produce a bright glow visible for about a week before fading. Brian Kloppenborg, Executive Director of the American Association of Variable Star Observers, likens the event to a hydrogen bomb due to the intense release of energy.

Observational Opportunities

Koji Mukai, an astrophysics researcher at NASA, notes that T CrB’s nova will likely be the brightest since Nova Cygni in 1975, which had a peak magnitude of 2.0. The magnitude scale, dating back to early astronomers, measures a star’s brightness as seen from Earth. The brightest stars are first magnitude, while the dimmest visible to the naked eye are sixth magnitude.

With modern technology, researchers aim to gain unprecedented insights into T CrB’s nova. Advanced ground-based and space-borne instruments will provide a comprehensive view of the event.

Predicting the Eruption

Researchers predicted T CrB’s imminent eruption by observing a sudden drop in its brightness in April 2023, a pattern that typically precedes a nova by about a year. Brad Schaefer, an astronomy professor at Louisiana State University, confirmed that this dip aligns with patterns observed before the 1946 eruption.

The eruption process lasts about 60 days, with peak brightness for no more than three days. Unlike a supernova, which destroys the star, a nova allows the white dwarf to remain intact and repeat the process over hundreds of thousands of years.

Rebekah Hounsell, a NASA scientist, emphasizes the rarity and excitement of witnessing such an event so close to our solar system.

Summary

• Event: Predicted nova eruption of T Coronae Borealis (T CrB) by September.
• Historical Context: Novae have been studied for centuries, advancing our understanding of stellar evolution.
• Star System: T CrB consists of a white dwarf and a red giant.
• Frequency: Erupts approximately every 80 years; last visible in 1946.
• Visibility: Bright glow visible for about a week.
• Magnitude: Expected to be the brightest nova since 1975.
• Prediction: Based on a sudden drop in brightness in April 2023.
• Duration: Eruption process lasts about 60 days, peak brightness for three days.
• Difference from Supernova: Nova does not destroy the star; the process can repeat.

This event offers a unique observational opportunity for astronomers and enthusiasts alike, providing valuable data to further our understanding of stellar phenomena.