2021-07-13

Research: Teardrop-shaped stars are driving another star to become a supernova

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Research: Teardrop-shaped stars are driving another star to become a supernova

This is a hot subdwarf star, most likely the result of a larger star, which previously broke away from its outer layer and peeled off into The core of helium is now being fused. But the strangest thing is that its light changes in an unusual pattern, which shows that the star is not spherical, but elongated like teardrops. The reason for this is that there is a smaller, darker but denser companion nearby. Close observation revealed that this hot subdwarf star and a white dwarf star are in a very close orbit, revolving around each other once every 100 minutes.

Facts have proved that this structure will eventually lead to their destruction. Astronomers discovered that the two stars spiraled toward each other and eventually merged into one. When this happens, it will cause a huge explosion, which is a Type Ia supernova.

This kind of supernova phenomenon occurs when the white dwarf accumulates too much mass to remain stable, and it also experiences an out-of-control thermonuclear process. The Chandrasekha limit is 1.44 solar masses, and the total mass of this star system is 1.65 solar masses, which means that Type Ia supernovae are almost inevitable.

“We don’t know how these supernovae exploded, but we know it will happen because we see it happening elsewhere in the universe,” said Dr. Ingrid Pelisoli, lead author of the study’s paper “One method is for the white dwarf star to accumulate enough mass from the hot subdwarf star, so when the two planets orbit each other and get closer, the matter will begin to escape from the hot subdwarf star and fall onto the white dwarf Another method is that because their energy is consumed by the release of gravitational waves, they will get closer and closer until they merge. Once the white dwarf obtains enough mass from these two methods, it will become a supernova.”

Astronomers estimate that this system will explode in about 70 million years.