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The monster black hole According to a new study, the heart of the Milky Way is not the only celestial beast able to propel stars out of the galaxy.
Astronomers have traced the path of a huge "hypervelocity star"Over time, they discovered that the star, known as LAMOST-HVS1, was spinning in the Milky Way disk, not near the galactic core where the supermassive black hole is hiding. as previously suspected, according to a new study.
"This discovery radically changes our view of the origins of rapidly moving stars," said in a statement Monica Valluri, co-author of the study, professor of astronomy at the University of California. University of Michigan.
Related: The black holes of the universe in pictures
"The fact that the trajectory of this massive, fast-moving star is rooted in the disc rather than in the galactic center indicates that the extremely extreme environments needed to eject fast-moving stars can occur elsewhere than in the galactic center." around supermassive black holes, "said Valluri. added.
Hypervelocity stars travel in space at speeds above 1.6 million km / h, more than twice as fast as their "normal" cousins. These speedsters are quite rare. Astronomers discovered one in 2005 and have listed less than 30 since.
To reach their extraordinary speeds, hypervelocity stars must experience a powerful gravitational slingshot. The main suspect in most cases is Sagittarius A *, the central black hole of the Milky Way, home to about 4 million times the mass of the Earth's sun.
But something else seems to be happening with LAMOST-HVS1, which is the most known hypervelocal star of the Earth. The exotic object is about 42 000 light-years away from us. For perspective, the spiral disk of the Milky Way is about 100,000 light-years wide.
Valluri and his colleagues, led by Kohei Hattori, a postdoctoral researcher at the University of Michigan, traced the path of LAMOST-HVS1 with observations made by European researchers. Gaia Spacecraft and one of the Magellan twin telescopes, which are part of the Las Campanas Observatory in Chile.
"We thought this star was coming from the galactic center, but if you look at its trajectory, it's clear that it's not related to the galactic center," Hattori said. the same statement. "We must consider other possibilities for the origin of the star."
Hattori and his colleagues do not know how LAMOST-HVS1 got a speed boost, but they point out two main possibilities: the star may have had fascinating encounters with several massive stars, or perhaps been suspended off of the disc through an intermediary -mass the black hole in a cluster of stars.
The apparent path of LAMOST-HVS1 originates at a location in a spiral arm of the Milky Way called Norma. According to the researchers, no group of stars exists at this location, but one could hide there, hidden by the dust.
Thus, the locale settings of the LAMOST-HVS1 sling can be a good place to chase black mid-mass holes. These mysterious objects – whose masses lie between those of black holes of stellar mass and those of supermassive black holes – are considered to be common throughout the Milky Way. but they proved very hard to find or study.
The new study was published online on Tuesday, March 12 in The astrophysical journal.
Mike Wall's book on the search for extraterrestrial life, "Over there"(Grand Central Publishing, 2018, illustrated by Karl Tate), is out now. Follow him on Twitter @michaeldwall. Follow us on twitter @Spacedotcom or Facebook.
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