Peering deep into the vast stellar halo that envelops our Milky Way galaxy, astronomers using NASA’s Hubble Space Telescope have uncovered tantalizing evidence for the possible existence of a shell of stars that are a relic of cannibalism by our Milky Way.
Hubble was used to precisely measure, for the first time ever, the sideways motions of a small sample of stars located far from the galaxy’s center. Their unusual lateral motion is circumstantial evidence that the stars may be the remnants of a shredded galaxy that was gravitationally ripped apart by the Milky Way billions of years ago. These stars support the idea that the Milky Way grew, in part, through the accretion of smaller galaxies.
Finding the stars was meticulous work. Each Hubble image contained more than 100,000 stars. Astronomer Roeland van der Marel says, "We had to somehow find those few stars that actually belonged to the Milky Way halo. It was like finding needles in a haystack.
"Hubble’s unique capabilities are allowing astronomers to uncover clues to the galaxy’s remote past. The more distant regions of the galaxy have evolved more slowly than the inner sections. Objects in the outer regions still bear the signatures of events that happened long ago."
We’re going to discuss this in more detail at our extraordinary Revelations Nashville Symposium, May 17-19–a weekend with three of the most extraordinary thinkers in the world. Each speaker performs two events. To get your tickets, click here. The price includes breakfast Saturday and Sunday and lunch on Saturday.