Scientists have for the first time predicted a binary star system collision. In fact, the two stars – which are currently invisible to the naked eye – have already collided. They are located about 1800 light years away in the constellation Cygnus. Astronomers at the Calvin College in Michigan predict that the collision will lead to the formation of a Red Nova star in the night sky.

Red Nova Star Collision
Image Source: WikiImages / Pixabay

It will be visible to the naked eye for months

Astronomer Larry Molnar predicts that light from the collision would reach Earth in 2022, plus or minus one year. The collision will release so much energy that the binary star system’s brightness would increase by 10,000, making it visible to the naked eyes on Earth. The Red Nova will be one of the brightest stars in the night sky, said Larry Molnar at a meeting of the American Astronomical Society in Grapevine, Texas.

If the prediction turns out to be true, Molnar will be the first astronomer to predict the explosion of two giant stars merging. It would significantly improve our understanding of the binary star collision and the life-cycle of stars. Having data from before, during, and after such a stellar event would also offer insights into the formation and evolution of solar systems.

Two stars would merge to form a Red Nova

A binary star system is a solar system where two stars orbit one another (Watch Star Wars Episode IV). Molnar said it was not just a binary, but a “contact binary” system where the stars are close enough to share atmospheres. Molnar’s prediction is based on years of observation of a system called KIC 9832227. He and his colleagues noticed that the time taken by two stars to orbit each other was declining steadily. It means the bodies were likely to merge.

In the KIC 9832227 system, one star is 40% more massive than our sun while the other is one-third the size of the sun. The smaller star would eventually merge into its larger companion. Most of the energy will go towards the formation of the Red Nova with an even bigger core. The Red Nova gets its name from the color of light given off by the collision.

Astronomers had partial data on similar events

Molnar started studying such collisions taking inspiration from the works of Polish astronomer Romuald Tylenda. Tylenda observed such an explosion in 2008. She realized that she had partial data on the stars headed for the collision. She observed a pattern in that data. The stars grew closer together as they inched closer to the impact, and the length of time taken by stars to orbit was declining, reports Vox.

Then, Molnar and his students began looking for stars with similar accelerating orbits. They found a binary star system in 2013 that showed similar patterns as the 2008 explosion observed by Tylenda. Molnar and his colleagues have more than 33,000 images of KIC 9832227. Astronomers plan to continue to study the orbits of two planets.