Astronomers have detected in the stellar halo that represents the Milky Way's outer limits a group of stars more distant from Earth than any known within our own galaxy - almost halfway to a neighboring galaxy.
The researchers said these 208 stars inhabit the most remote reaches of the Milky Way's halo, a spherical stellar cloud dominated by the mysterious invisible substance called dark matter that makes itself known only through its gravitational influence. The furthest of them is 1.08 million light years from Earth. A light year is the distance light travels in a year, 5.9 trillion miles .
The stars that populate the outskirts of the galactic halo can be viewed as stellar orphans, probably originating in smaller galaxies that later collided with the larger Milky Way. "Their host galaxies have been gravitationally shredded and digested, but these stars are left at that large distance as debris of the merger event," Feng added."The larger galaxy grows by eating smaller galaxies - by eating its own kind," said study co-author Raja GuhaThakurta, UC Santa Cruz's chair of astronomy and astrophysics.
Dark matter, which dominates the halo, makes up most of the universe's mass and is thought to be responsible for its basic structure, with its gravity influencing visible matter to come together and form stars and galaxies.
日本 最新ニュース, 日本 見出し
Similar News:他のニュース ソースから収集した、これに似たニュース記事を読むこともできます。
Astronomers spot the most distant stars in the Milky Way — a million light-years awayThe farthest one is nearly halfway to the Andromeda Galaxy.
続きを読む »
Astronomers find 2nd Earth-size planet in intriguing alien solar systemMeghan is a senior writer at Space.com and has more than five years' experience as a science journalist based in New York City. She joined Space.com in July 2018, with previous writing published in outlets including Newsweek and Audubon. Meghan earned an MA in science journalism from New York University and a BA in classics from Georgetown University, and in her free time she enjoys reading and visiting museums. Follow her on Twitter at meghanbartels.
続きを読む »
Astronomers chart magnetic field of gigantic bubble surrounding EarthEnormous 'Swiss cheese' bubble surrounding Earth mapped in incredible new images
続きを読む »
Newly Found Stars are Technically in the Milky Way, but They're Halfway to AndromedaVariable stars called RR Lyrae stars stars offer clues to how far the Milky Way galaxy's outer stellar halo stretches toward Andromeda.
続きを読む »
Milky Way's Most Distant Stars Found Half Way to a Neighboring GalaxyWe all know our galaxy, the Milky Way, is big.
続きを読む »
James Webb telescope found distant galaxies that look just like the Milky WayAstronomers have detected Milky Way-like galaxies further back in the universe's history than they previously expected to.
続きを読む »