Labelled wide-field view of the Andromeda Galaxy (ground-based image): This ground-based image of the Andromeda Galaxy shows the location of four fields where the NASA/ESA Hubble Space Telescope has been used to study a wide variety of stars in the Andromeda Galaxy, ranging from faint main sequence stars like our own Sun, to the much brighter RR Lyrae stars, which are 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. The field marked A is located on the edge of the Andromeda Galaxy’s disc. The field marked B is in the giant stellar stream, a long swathe of stars left over from a smaller galaxy that was engulfed by the Andromeda Galaxy. Fields C and D are in the halo, a sparse sphere of stars and dark matter that surrounds the galaxy’s disc. Hubble’s very long exposures, combined with its excellent image quality, means that it is able to distinguish individual stars in these fields, even though they look virtually empty in this ground-based telescope’s image.

Name: Andromeda Galaxy, Messier 31
Type: Local Universe : Galaxy : Type : Spiral
Category: Galaxies
Distance: 2 million light years
Release date: 21 July 2011, 10:00
Credit: ESA/Hubble & Digitized Sky Survey 2. Acknowledgment: Davide De Martin (ESA/Hubble)

Labelled wide-field view of the Andromeda Galaxy (ground-based image): This ground-based image of the Andromeda Galaxy shows the location of four fields where the NASA/ESA Hubble Space Telescope has been used to study a wide variety of stars in the Andromeda Galaxy, ranging from faint main sequence stars like our own Sun, to the much brighter RR Lyrae stars, which are 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. The field marked A is located on the edge of the Andromeda Galaxy’s disc. The field marked B is in the giant stellar stream, a long swathe of stars left over from a smaller galaxy that was engulfed by the Andromeda Galaxy. Fields C and D are in the halo, a sparse sphere of stars and dark matter that surrounds the galaxy’s disc. Hubble’s very long exposures, combined with its excellent image quality, means that it is able to distinguish individual stars in these fields, even though they look virtually empty in this ground-based telescope’s image.

Name: Andromeda Galaxy, Messier 31
Type: Local Universe : Galaxy : Type : Spiral
Category: Galaxies
Distance: 2 million light years
Release date: 21 July 2011, 10:00
Credit: ESA/Hubble & Digitized Sky Survey 2. Acknowledgment: Davide De Martin (ESA/Hubble)

Labelled wide-field view of the Andromeda Galaxy (ground-based image): This ground-based image of the Andromeda Galaxy shows the location of four fields where the NASA/ESA Hubble Space Telescope has been used to study a wide variety of stars in the Andromeda Galaxy, ranging from faint main sequence stars like our own Sun, to the much brighter RR Lyrae stars, which are 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. The field marked A is located on the edge of the Andromeda Galaxy’s disc. The field marked B is in the giant stellar stream, a long swathe of stars left over from a smaller galaxy that was engulfed by the Andromeda Galaxy. Fields C and D are in the halo, a sparse sphere of stars and dark matter that surrounds the galaxy’s disc. Hubble’s very long exposures, combined with its excellent image quality, means that it is able to distinguish individual stars in these fields, even though they look virtually empty in this ground-based telescope’s image.

Name: Andromeda Galaxy, Messier 31
Type: Local Universe : Galaxy : Type : Spiral
Category: Galaxies
Distance: 2 million light years
Release date: 21 July 2011, 10:00
Credit: ESA/Hubble & Digitized Sky Survey 2. Acknowledgment: Davide De Martin (ESA/Hubble)

Labelled wide-field view of the Andromeda Galaxy (ground-based image): This ground-based image of the Andromeda Galaxy shows the location of four fields where the NASA/ESA Hubble Space Telescope has been used to study a wide variety of stars in the Andromeda Galaxy, ranging from faint main sequence stars like our own Sun, to the much brighter RR Lyrae stars, which are 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. The field marked A is located on the edge of the Andromeda Galaxy’s disc. The field marked B is in the giant stellar stream, a long swathe of stars left over from a smaller galaxy that was engulfed by the Andromeda Galaxy. Fields C and D are in the halo, a sparse sphere of stars and dark matter that surrounds the galaxy’s disc. Hubble’s very long exposures, combined with its excellent image quality, means that it is able to distinguish individual stars in these fields, even though they look virtually empty in this ground-based telescope’s image.

Name: Andromeda Galaxy, Messier 31
Type: Local Universe : Galaxy : Type : Spiral
Category: Galaxies
Distance: 2 million light years
Release date: 21 July 2011, 10:00
Credit: ESA/Hubble & Digitized Sky Survey 2. Acknowledgment: Davide De Martin (ESA/Hubble)

Wide-field view of the Andromeda Galaxy: This ground-based image shows the full extent of the Andromeda Galaxy, also known as Messier 31 or M 31. The Andromeda Galaxy appears very large in the sky — several times the size of the full Moon (although much fainter). Hubble is designed to make highly detailed observations of much smaller patches of sky: the space telescope’s observations of the Andromeda Galaxy show individual stars and clusters rather than the broad spiral structure visible here. Wide-field images like this one give a broad overview.

Name: Andromeda Galaxy, Messier 31
Type: Local Universe : Galaxy : Type : Spiral
Category: Galaxies
Constellation: Andromeda
Distance: 2 million light years
Release date: 21 July 2011, 10:00
Credit: ESA/Hubble & Digitized Sky Survey 2. Acknowledgment: Davide De Martin (ESA/Hubble)

Wide-field view of the Andromeda Galaxy: This ground-based image shows the full extent of the Andromeda Galaxy, also known as Messier 31 or M 31. The Andromeda Galaxy appears very large in the sky — several times the size of the full Moon (although much fainter). Hubble is designed to make highly detailed observations of much smaller patches of sky: the space telescope’s observations of the Andromeda Galaxy show individual stars and clusters rather than the broad spiral structure visible here. Wide-field images like this one give a broad overview.

Name: Andromeda Galaxy, Messier 31
Type: Local Universe : Galaxy : Type : Spiral
Category: Galaxies
Constellation: Andromeda
Distance: 2 million light years
Release date: 21 July 2011, 10:00
Credit: ESA/Hubble & Digitized Sky Survey 2. Acknowledgment: Davide De Martin (ESA/Hubble)

Wide-field view of the Andromeda Galaxy: This ground-based image shows the full extent of the Andromeda Galaxy, also known as Messier 31 or M 31. The Andromeda Galaxy appears very large in the sky — several times the size of the full Moon (although much fainter). Hubble is designed to make highly detailed observations of much smaller patches of sky: the space telescope’s observations of the Andromeda Galaxy show individual stars and clusters rather than the broad spiral structure visible here. Wide-field images like this one give a broad overview.

Name: Andromeda Galaxy, Messier 31
Type: Local Universe : Galaxy : Type : Spiral
Category: Galaxies
Constellation: Andromeda
Distance: 2 million light years
Release date: 21 July 2011, 10:00
Credit: ESA/Hubble & Digitized Sky Survey 2. Acknowledgment: Davide De Martin (ESA/Hubble)