A strange metal-rich star catapulted from the galaxy

by



[ad_1]

Spherical shiny orange cloud with a small white object sticking out of it - a star rich in metal has catapulted.
Artist’s concept of the core of a star rushing outward as shrapnel from a supernova explosion. Astronomers believe it’s a metal-rich star catapulted from our galaxy. Image via JJ Hermes (@jotajotahermes) on Twitter.

A star rich in metals catapulted

A star rich in metals, believed to be the glow of a supernova, is emerging from our galaxy at lightning speed. The star is called LP 40-365. It is just 2,000 light years away in the Milky Way. And it is constantly increasing its distance from Earth. Boston University astronomer JJ Hermes said in a statement:

This star is moving so fast that it is almost certainly leaving the galaxy … [it’s] moving at nearly 2 million miles per hour [3.2 million kph].

This contrasts with the movement of our sun in space, which is about 448,000 miles per hour (72,000 km / h). Boston University released information on this star earlier this summer (July 8, 2021). The study published by the scientists appeared on June 7 in the peer-reviewed journal Letters from astrophysical journals.

supernova shrapnel

This bizarre star is one of an elite group of fast moving star remnants. Part of the star’s core apparently survived the supernova explosion intact. This nucleus was thrown into space in the form of shrapnel by the force of the explosion of the supernova. The piece continues to move away from the site of the explosion. And we think it will make an eventual exit from our galaxy. Boston University astronomer Odelia Putterman, co-author of the study, said:

To have suffered a partial detonation and survive is very cool and unique. And it was only in the last few years that we started to think that this kind of star could exist.

These supernova flashing stars are the fastest moving stars known. And, perhaps not by coincidence, they are also the most metal-rich celebs seen to date. Hermès said:

These are very strange stars… What we are seeing are the byproducts of violent nuclear reactions that occur when a star explodes.

By the way, the word “metals” doesn’t mean what you might think when used in relation to a star. For an astronomer, “metals” are elements heavier than hydrogen or helium. As you may know, the heaviest elements are forged inside the stars. This particular star is rich in “metals” such as neon and oxygen.

Smiling middle aged man with dark hair and short beard wearing blue shirt with open collar.
JJ Hermes of Boston University was the lead author of the article. Image via Boston University.
Smiling young woman with long dark hair pulled back.
Odelia Putterman is an undergraduate student from Boston University who was the author of the study. Image via Boston University.

Which star survived?

The team made the discovery using data from the Hubble Space Telescope and NASA’s Transiting Exoplanet Study (TESS) satellite. As LP 40-365 rolls out of the galaxy, survey data has shown a change in brightness. The data indicates that the star is spinning or spinning. Putterman said:

The star is actually dropped by the explosion, and we are [observing] its rotation on exit.

Hermès explained:

We dug a little deeper to understand why this star [was repeatedly] more and more bright and fainter, and the simplest explanation is that we are seeing something at [its] the surface rotates in and out of sight every nine hours.

This rate of rotation can tell astronomers what kind of system this strange, metal-rich star came from. Type 1a supernovae occur when a pair of orbiting white dwarf stars become unstable. A white dwarf siphons matter from the other until its mass becomes so large that it sets off an explosion. In May, Hermes said in a tweet:

We’re pretty sure… a binary star has undergone a thermonuclear supernova. We’re less sure if survivor LP 40-365 was the exploded star, or the donor of the exploded star.

The nine-hour turnover rate is a clue, however. The mid-July statement from these astronomers read:

Based on the relatively slow spin rate of the LP 40-365, Hermes and Putterman are more confident that these are shrapnel from the star that self-destructs… Because the stars were spinning so fast and so tightly, l explosion fired at the two stars. And now we only see LP 40-365.

Scientists hope their discovery may shed light on other pairs of white dwarfs as well as supernovae. Putterman said their article:

… Adds an extra layer of knowledge about the role these stars played when the supernova occurred. By understanding what is happening with that particular star, we can begin to understand what is happening with many other similar stars from a similar situation.

Two spheres orbit each other, matter flowing from one in a ring around the other.
Artist concept of 2 white dwarf stars. These are the hot, dense remnants of long-dead stars. In this system, one star pulls matter from the other. Ultimately, this scenario can lead to mass overload and a supernova. Image via ZTF / Caltech.

Bottom line: Scientists have discovered a star rich in metals that they believe to be shrapnel from a supernova explosion. The star leaves our galaxy at nearly 2 million miles per hour (3.2 million km / h).

Source: 8.9 hour rotation in LP 40-365 (GD 492) of the leaking partially burned stellar remains

Preprint at arXiv

Via Boston University

Kelly kizer whitt

View Articles

About the Author:

Kelly Kizer Whitt has been a science writer specializing in astronomy for over two decades. She started her career at Astronomy Magazine and has regularly contributed to AstronomyToday and the Sierra Club, among others. Her children’s picture book, Solar System Forecast, was published in 2012. She also wrote a dystopian young adult novel called A Different Sky. When not reading or writing about astronomy and gazing at the stars, she enjoys traveling in national parks, creating crosswords, running, playing tennis, and paddleboarding. Kelly lives with her family in Wisconsin.



[ad_2]

Source link