Outer Stars of The Andromeda Galaxy | Hubble Space Telescope

Outer Stars of The Andromeda Galaxy | Hubble Space Telescope

The Andromeda Galaxy is a barred spiral galaxy and is the nearest major galaxy to the Milky Way. Distance: 2 million light-years

It is thought that the Milky Way and Andromeda galaxies will collide several billion years from now.

Images 1&2: Stars in the Andromeda Galaxy’s giant stellar stream

These NASA/European Space Agency Hubble Space Telescope images are of a small part of the giant stellar stream of the Andromeda Galaxy. The stream is a long structure thought to be the remains of a companion galaxy torn apart by the Andromeda Galaxy’s gravity and engulfed in it.

Images 3&4: Stars in the Andromeda Galaxy’s halo with background galaxies 

These NASA/European Space Agency Hubble Space Telescope images are of a small part of the halo of the Andromeda Galaxy. The halo is the huge and sparse sphere of stars that surrounds a galaxy. While there are relatively few stars in a galaxy’s halo, studies of the rotation rate of galaxies suggest that there is a great deal of invisible dark matter here.

Hubble’s position above the distorting effect of the atmosphere, combined with this galaxy’s relative proximity, means that these images can be resolved into individual stars, rather than the cloudy white wisps usually seen in observations of galaxies. In the background, many faraway galaxies are visible, billions of light-years further away than the Andromeda Galaxy.

Andromeda’s proximity to the Milky Way means it looks larger than other galaxies from Earth: Seen with the naked eye, Andromeda would be about six times the width of the Moon (about 3 degrees)

These observations were made in order to observe a wide variety of stars in Andromeda, ranging from faint main sequence stars like our own Sun, to the much brighter RR Lyrae stars—a type of variable star. With these measurements, astronomers can determine the chemistry and ages of the stars in each part of the Andromeda Galaxy.

Image Credits: NASA, ESA and T.M. Brown/Space Telescope Science Institute

Release Date: July 21, 2011

#NASA #ESA #Astronomy #Space #Science #Hubble #Stars #Galaxies #Galaxy #AndromedaGalaxy #Messier31 #M31 #Andromeda #Constellation #AndromedaGalaxy #Cosmos #Universe #HST #HubbleSpaceTelescope #GSFC #STScI #UnitedStates #Europe #STEM #Education