Hubble Peers at Andromeda’s Halo

The Hubble Space Telescope mapped the halo of the Andromeda galaxy, revealing our galactic neighbor in a new light.

A magnificent cloud of diffuse halo of plasma surrounding our galactic neighbor, Andromeda, was recently mapped by astronomers using the Hubble Space Telescope.

This envelope of electrically-charged particles stretches 1.3 million light years from it’s home galaxy, halfway to the Milky Way. In some places, Andromeda’s halo stretches two million light years from its parent galaxy, two-thirds of the way to our home galaxy.

An artist’s concept of what the halo of Andromeda might look like from Earth, were we able to see light from this thin cloud of gas. Image credit: NASA, ESA, J. DePasquale and E. Wheatley (STScI), and Z. Levay (background image)

This close proximity means that Andromeda, destined to collide with the Milky Way in several billion years, has made “first contact” with our home galaxy.

Halo… Halo… Halo… Is there Anybody Out There?

The halo was found to possess a layered structure containing a pair of distinct nested shells of gas. Examination of this halo, which supplies material for the formation of stars, can reveal information about the birth and deaths of stars within the Andromeda Galaxy. The discovery of heavy elements, produced in the explosions of massive supernova stars, reveals evidence for the deaths of vast numbers of behemoth stars.