Astronomers report a “supernova” in the Milky Way

Written by Will Dunham

WASHINGTON – Supernovas aren’t always pretty. These explosions that mark the death of a star are usually incredibly powerful. But sometimes, they stay alone.

Scientists on Wednesday revealed one of the duds – a massive star that was captured by the gravitational pull of a companion star in a binary system that was exploding at the end of the it. the cycle of life could not control the crying.

In fact, its explosion was so easy that the collapsed star – now an incredibly dense object called a neutron star – remains in a simple circular orbit. and its partner. A more powerful explosion would have created an oval-shaped orbit, which would have caused the star and its companion to spin in opposite directions.

This binary system, studied with a telescope at Chile’s Cerro Tololo Inter-American Observatory, is located about 11,000 light-years from Earth in our Milky Way galaxy. Puppis constellation. A light year is the distance that light travels in a year, 5.9 trillion miles (9.5 trillion km).

The mass of the neutron star is about 1.4 times that of our sun, as it was previously 12 times more massive than the sun. Its companion star boasts a mass greater than the sun 18 to 19 times after it eats its mate. The two stars orbit every 59-1/2 days, separated by about one-eighteenth of the distance between Earth and the sun.

The resulting explosion of an anemic star was called an “ultra-stripped” supernova. This happens when a massive star collapses when it runs out of fuel in its core, but is unable to sustain a powerful explosion because the companion star has lost most of its outer layers and removed the material from its core. they can be violently ejected from the atmosphere.

“Because there’s so little material in the star’s envelope, there’s almost no ejecta from the shock,” said Arizona-based astronomer Noel Richardson of Embry-Riddle Aeronautical University, an author on in a study published in the journal Nature.

Study co-author Clarissa Pavao, an Embry-Riddle student studying physics, described the explosion as: “Weak, subtle, and nothing.”

“If there was a big bang, the cycle wouldn’t be a circle,” Richardson said. “A normal supernova would not destroy the companion, but it could disturb the orbit further. For example, it could help the system to make the orbit more circular or send the rest of the star out of the star. of neutrons in different velocities at speeds that would eject them from the galaxy.”

The type of binary system analyzed in this study is rare, about 10 are estimated to exist in the Milky Way which contains about 100-400 billion stars.

Unlike the lonely sun, perhaps half of the stars in our galaxy reside in binary systems. Scientists have speculated whether planets capable of sustaining life exist in such systems, as demonstrated, for example, by the home planet of “Star Wars” Luke Skywalker, Tatooine.

“We know of other binary systems with planets, but these are difficult to confirm, and these are all stars with masses like our sun,” Richardson said. “In the case of these massive stars, we have not seen any planets around them. The stars are much more massive and brighter than sun-like stars, making detecting planets more difficult than orbiting smaller stars.”

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