Young and Old Stars Found in Andromeda's Halo: The deepest visible-light image ever taken of the sky resolves approximately 300, 000 stars in the halo of the nearest neighboring spiral galaxy, Andromeda (M31). The photo was taken with the Advanced Camera for Surveys aboard the NASA/ESA Hubble Space Telescope. Because the image captures both faint dwarf stars and bright giant stars, astronomers can estimate the age of the halo population by analyzing its distribution of colour and brightness. The halo is a spherical cloud of stars around Andromeda, located 2.5 million light-years from Earth.

Name: Andromeda Galaxy, Messier 31, NGC 224
Type: Local Universe : Galaxy : Type : SpiralLocal Universe : Galaxy : Component : Halo
Category: Galaxies
Constellation: Andromeda
Distance: 2 million light years
Release date: 7 May 2003, 15:45
Credit: NASA, ESA and T.M. Brown (STScI)

Andromeda Galaxy Halo Details - 1: Relying on the deepest visible-light images ever taken in space, astronomers using NASA's Hubble Space Telescope (HST) have reliably measured the age of the spherical halo of stars surrounding the neighboring Andromeda galaxy (M31). To their surprise, they have discovered that approximately one-third of the stars in Andromeda's halo formed only 6 to 8 billion years ago. That's a far cry from the 11-to-13 billion-year age of the stars in the Milky Way's halo.

Name: Andromeda Galaxy, Messier 31, NGC 224
Type: Local Universe : Galaxy : Type : SpiralLocal Universe : Galaxy : Component : Halo
Category: Galaxies
Constellation: Andromeda
Distance: 2 million light years
Release date: 7 May 2003, 15:45
Credit: NASA, ESA and T.M. Brown (STScI)

Andromeda Galaxy Halo Details - 2: Relying on the deepest visible-light images ever taken in space, astronomers using NASA's Hubble Space Telescope (HST) have reliably measured the age of the spherical halo of stars surrounding the neighboring Andromeda galaxy (M31). To their surprise, they have discovered that approximately one-third of the stars in Andromeda's halo formed only 6 to 8 billion years ago. That's a far cry from the 11-to-13 billion-year age of the stars in the Milky Way's halo.

Name: Andromeda Galaxy, Messier 31, NGC 224
Type: Local Universe : Galaxy : Type : SpiralLocal Universe : Galaxy : Component : Halo
Category: Galaxies
Constellation: Andromeda
Distance: 2 million light years
Release date: 7 May 2003, 15:45
Credit: NASA, ESA and T.M. Brown (STScI)

Andromeda Galaxy Halo Details - 3: Relying on the deepest visible-light images ever taken in space, astronomers using NASA's Hubble Space Telescope (HST) have reliably measured the age of the spherical halo of stars surrounding the neighboring Andromeda galaxy (M31). To their surprise, they have discovered that approximately one-third of the stars in Andromeda's halo formed only 6 to 8 billion years ago. That's a far cry from the 11-to-13 billion-year age of the stars in the Milky Way's halo.

Name: Andromeda Galaxy, Messier 31, NGC 224
Type: Local Universe : Galaxy : Type : SpiralLocal Universe : Galaxy : Component : Halo
Category: Galaxies
Constellation: Andromeda
Distance: 2 million light years
Release date: 7 May 2003, 15:45
Credit: NASA, ESA and T.M. Brown (STScI)

Andromeda Galaxy Halo Details - 4: Relying on the deepest visible-light images ever taken in space, astronomers using NASA's Hubble Space Telescope (HST) have reliably measured the age of the spherical halo of stars surrounding the neighboring Andromeda galaxy (M31). To their surprise, they have discovered that approximately one-third of the stars in Andromeda's halo formed only 6 to 8 billion years ago. That's a far cry from the 11-to-13 billion-year age of the stars in the Milky Way's halo.

Name: Andromeda Galaxy, Messier 31, NGC 224
Type: Local Universe : Galaxy : Type : SpiralLocal Universe : Galaxy : Component : Halo
Category: Galaxies
Constellation: Andromeda
Distance: 2 million light years
Release date: 7 May 2003, 15:45
Credit: NASA, ESA and T.M. Brown (STScI)

Andromeda Galaxy Halo Details - 5: Relying on the deepest visible-light images ever taken in space, astronomers using NASA's Hubble Space Telescope (HST) have reliably measured the age of the spherical halo of stars surrounding the neighboring Andromeda galaxy (M31). To their surprise, they have discovered that approximately one-third of the stars in Andromeda's halo formed only 6 to 8 billion years ago. That's a far cry from the 11-to-13 billion-year age of the stars in the Milky Way's halo.

Name: Andromeda Galaxy, Messier 31, NGC 224
Type: Local Universe : Galaxy : Type : SpiralLocal Universe : Galaxy : Component : Halo
Category: Galaxies
Constellation: Andromeda
Distance: 2 million light years
Release date: 7 May 2003, 15:45
Credit: NASA, ESA and T.M. Brown (STScI)

Andromeda Galaxy Halo Details - 6: Relying on the deepest visible-light images ever taken in space, astronomers using NASA's Hubble Space Telescope (HST) have reliably measured the age of the spherical halo of stars surrounding the neighboring Andromeda galaxy (M31). To their surprise, they have discovered that approximately one-third of the stars in Andromeda's halo formed only 6 to 8 billion years ago. That's a far cry from the 11-to-13 billion-year age of the stars in the Milky Way's halo.

Name: Andromeda Galaxy, Messier 31, NGC 224
Type: Local Universe : Galaxy : Type : SpiralLocal Universe : Galaxy : Component : Halo
Category: Galaxies
Constellation: Andromeda
Distance: 2 million light years
Release date: 7 May 2003, 15:45
Credit: NASA, ESA and T.M. Brown (STScI)

Relative location of M31 and Milky Way: Relying on the deepest visible-light images ever taken in space, astronomers using NASA's Hubble Space Telescope (HST) have reliably measured the age of the spherical halo of stars surrounding the neighboring Andromeda galaxy (M31).

Name: Andromeda Galaxy, Messier 31, Milky Way
Type: Milky Way : GalaxyLocal Universe : Galaxy : Type : Spiral
Category: GalaxiesIllustrations
Release date: 7 May 2003, 15:45
Credit: NASA/ESA and A. Feild (STScI)

H-R diagram comparing ages of Milky Way and M31: Relying on the deepest visible-light images ever taken in space, astronomers using NASA's Hubble Space Telescope (HST) have reliably measured the age of the spherical halo of stars surrounding the neighboring Andromeda galaxy (M31).

Name: Andromeda Galaxy, Messier 31, Milky Way
Type: Milky Way : GalaxyLocal Universe : Galaxy : Type : Spiral
Category: GalaxiesIllustrations
Release date: 7 May 2003, 15:45
Credit: NASA/ESA and A. Feild (STScI)

Supernova Shock Wave Paints Cosmic Portrait: Remnants from a star that exploded thousands of years ago created a celestial abstract portrait, as captured in this NASA/ESA Hubble Space Telescope image of the Pencil Nebula. Officially known as NGC 2736, the Pencil Nebula is part of the huge Vela supernova remnant, located in the southern constellation Vela. Discovered by Sir John Herschel in the 1840s, the nebula's linear appearance triggered its popular name. The nebula's shape suggests that it is part of the supernova shock wave that recently encountered a region of dense gas. It is this interaction that causes the nebula to glow, appearing like a rippled sheet.

Name: NGC 2736, Pencil Nebula
Type: Milky Way : Nebula : Type : Supernova Remnant
Category: Nebulae
Constellation: Vela
Distance: 1600 light years
Release date: 5 June 2003, 15:00
Credit: NASA/ESA and The Hubble Heritage Team (STScI/AURA)