October 30, 2024
2 minimum read
Fastest known planetary system may have been pushed out by our galaxy’s supermassive black hole
This fast-moving star is tearing through the Milky Way, taking planets with it.
A view of the dense region of stars near the center of the Milky Way called the Galactic Bulge, taken by the Hubble Space Telescope.
Our solar system orbits the Milky Way galaxy about once every 225 million years, traveling at 230 kilometers per second (this amazing speed is because everything moves at the same constant speed). (I can’t feel it). But a new study suggests that we are a cosmic blunt instrument when compared to one star system in our galaxy (the fastest known planetary system), which was somehow blown away at a speed of 541 kilometers per second. I’m doing it.
“This speed was so fast that it was kind of shocking,” said University of Maryland astrophysicist Sean Terry, lead author of the study posted on the preprint server arXiv.org and submitted to an academic journal. say. astrophysical journal. “It raises a series of questions about the viability of this type of system.”
This galactic speed demon appears to have a red dwarf star that is smaller and dimmer than our Sun. It is approximately 25,000 light-years from Earth and approximately 1,000 light-years from the center of the galaxy. Astronomers discovered the star and its possible companion planet after a 2011 microlensing event called MOA-2011-BLG-262. In doing so, the system passed in front of the background star, distorting the latter’s light.
About supporting science journalism
If you enjoyed this article, please consider supporting our award-winning journalism. Currently subscribing. By subscribing, you help ensure future generations of influential stories about the discoveries and ideas that shape the world today.
Terry and his colleagues observed the system again in 2021 from the WM Keck Observatory in Hawaii. They discovered that the known planet is probably a gas giant, about 29 times the mass of Earth, and orbits its star at a distance between the distance that Venus and Earth orbit the Sun. (The system may also have unseen planets.) The researchers also mapped the system’s position in 2021 data compared to its position about a decade ago, showing that the system is It revealed how fast it was moving.
This speed suggests that the stars in this system may be hypervelocity stars. This is an example of a rare type of stellar object that has been accelerated by past encounters with other stars, and could even be a gravitational slingshot from the supermassive black hole at the center of our galaxy. . These objects travel at more than 500 kilometers per second, and the fastest known objects travel at breakneck speeds of more than 2,000 kilometers per second. “This is a truly exotic piece of star,” says Terry, who estimates that the system more than doubled in speed after the dramatic encounter. No hypervelocity stars have been discovered along with planets, he added.
Jesse Christiansen of NASA’s Exoplanet Science Institute, who was not involved in the study, said the system could provide insight into what kind of worlds exist in the star-dense region at the center of our galaxy. He says he will provide clues. We don’t know whether being inside that galactic bulge “will influence the types of planetary systems that form,” she says.
The known planets in this high-velocity system orbit far from the zone around the red dwarf star where liquid water (and therefore life as we know it) could exist on its surface; This suggests that the planet can withstand the “somewhat chaotic interactions” that occur when stars collide. Terry says it accelerated to a tremendous speed. “This may open new research into the origin and evolution of planets around very fast stars,” he added.
