Merging galaxies — 2.4 billion light-years from Earth: Merging galaxies — 2.4 billion light-years from Earth.

Type: Early Universe : Galaxy : Type : Interacting
Category: Galaxies
Constellation: Bootes
Release date: 27 October 2011, 17:06
Credit: NASA, ESA, and J. Lotz (STScI)

Merging galaxies — 3 billion light-years from Earth: Merging galaxies — 3 billion light-years from Earth.

Type: Early Universe : Galaxy : Type : Interacting
Category: Galaxies
Constellation: Bootes
Distance: 3 billion light years
Release date: 27 October 2011, 17:09
Credit: NASA, ESA, and J. Lotz (STScI)

Merging galaxies — 5.3 billion light-years from Earth: Merging galaxies — 5.3 billion light-years from Earth.

Type: Early Universe : Galaxy : Type : Interacting
Category: Galaxies
Constellation: Bootes
Distance: 6 billion light years
Release date: 27 October 2011, 17:12
Credit: NASA, ESA, and J. Lotz (STScI)

Merging galaxies — 6.2 billion light-years from Earth: Merging galaxies — 6.2 billion light-years from Earth.

Type: Early Universe : Galaxy : Type : Interacting
Category: Galaxies
Constellation: Bootes
Distance: 6 billion light years
Release date: 27 October 2011, 17:16
Credit: NASA, ESA, and J. Lotz (STScI)

Simulated images of merging galaxies: These illustrations demonstrate how two galaxies coalesce in a slow dance that lasts about a billion years. The graphics are taken from a simulation astronomers created to determine how long it takes for galaxies to complete a merger. By understanding the time it takes for two merging systems to become one normal-looking galaxy, astronomers can calculate how many galaxy encounters happen over time. This information yields important clues about how galaxies have changed throughout the Universe's history.

Type: Unspecified : Galaxy : Type : Interacting
Category: Illustrations
Release date: 27 October 2011, 17:19
Credit: P. Jonsson (Harvard-Smithsonian Center for Astrophysics, USA), G. Novak (Princeton University, USA), and T.J. Cox (Carnegie Observatories, Pasadena, Calif., USA)

Extended Groth Strip: Extended Groth Strip.

Type: Unspecified : Galaxy
Category: CosmologyGalaxies
Constellation: Bootes
Release date: 27 October 2011, 17:54
Credit: NASA, ESA, M. Davis (University of California, Berkeley), and A. Koekemoer (STScI)

Hubble snags one of the farthest exploding stars: These three images taken by the NASA/ESA Hubble Space Telescope reveal the emergence of an exploding star, called a supernova. Nicknamed SN Primo, the exploding star belongs to a special class called Type Ia supernovae, which are distance markers used for studying dark energy and the expansion rate of the universe. Type Ia supernovae most likely arise when white dwarf stars — the burned-out cores of normal stars — siphon too much material from their companion stars and explode. The top image shows part of the Hubble Ultra Deep Field, the region where astronomers were looking for a supernova blast. The white box pinpoints the area where the supernova is later seen. The image combines observations taken in visible and near-infrared light with the Advanced Camera for Surveys and the Wide Field Camera 3. The image at bottom left, taken by the Wide Field Camera 3, is a close-up of the field without the supernova. A new bright object, identified as the supernova, appears in the Wide Field Camera 3 image at bottom right. The exploding star was discovered as part of a search for distant Type Ia supernovae called the CANDELS+CLASH Supernova Project. The supernova team's search technique involved taking multiple near-infrared images over several months, looking for a supernova's faint glow. Once the team spotted the stellar blast in October 2010, they used WFC3's spectrometer to verify SN Primo's distance and to decode its light, finding the unique signature of a Type Ia supernova. The team then re- imaged SN Primo periodically for several months, measuring the slow dimming of its light.

Name: HUDF
Type: Early Universe : Star : Evolutionary Stage : Supernova
Category: Stars
Distance: z=1.55 (redshift)
Release date: 12 January 2012, 16:18
Credit: NASA, ESA, A. Riess (Space Telescope Science Institute and The Johns Hopkins University), and S. Rodney (The Johns Hopkins University)

HUDF image including location of SN Primo: This image shows part of the Hubble Ultra Deep Field, a region where astronomers confirmed the most distant Type Ia supernova yet observed.

Name: HUDF
Type: Early Universe : Cosmology : Morphology : Deep Field
Category: Stars
Constellation: Fornax
Release date: 12 January 2012, 16:20
Credit: NASA, ESA, A. Riess (STScI and JHU), and S. Rodney (JHU)

Hubble observes blue stars in Andromeda's core: The image at left shows the nearby, majestic Andromeda galaxy. The rectangular box marks the region probed by NASA's Hubble Space Telescope. Hubble's view, taken with the Wide Field Camera 3 and the Advanced Camera for Surveys, is shown in the images on the right. The images are a blend of visible and ultraviolet light. The photo at top right is 7,900 light-years across and reveals the galaxy's crowded central region. The bright area near the center of the image is a grouping of stars nestled around the galaxy's black hole. The blue dots sprinkled throughout the image are ultra-blue stars whose population increases around the crowded hub. The blue stars are old Sun-like stars that have prematurely cast off their outer layers of material, exposing their extremely blue-hot cores. The square box outlines a close-up view of an area around the core. The detailed image, shown at bottom right, reveals a richer population of blue stars huddled around the core. Dark dust clouds also are visible. The image is 740 light-years wide. The right-hand images, taken with Hubble, are part of a census of stars in M31 called the Panchromatic Hubble Andromeda Treasury survey. The image of the Andromeda galaxy was taken on 13 June 2001, with the WIYN/KPNO 0.9-meter Mosaic I by T. Rector and B. Wolpa of the National Optical Astronomy Observatory in Tucson, Arizona (USA).

Name: Andromeda Galaxy, M 31, Messier 31, NGC 224
Type: Local Universe : Galaxy : Type : Spiral
Category: Galaxies
Release date: 11 January 2012, 19:59
Credit: NASA, ESA, B.F. Williams (University of Washington, Seattle), D. Lang (Princeton University, N.J.), J. Kalirai (Space Telescope Science Institute, Baltimore), and J. Dalcanton (University of Washington, Seattle)

Ground-based image of Andromeda Galaxy, M31: This image, from the WIYN/KPNO 0.9-meter telescope, shows the Andromeda Galaxy, the nearest spiral galaxy to the Milky Way.

Name: Andromeda Galaxy, M 31, Messier 31, NGC 224
Type: Local Universe : Galaxy : Type : Spiral
Category: Galaxies
Release date: 11 January 2012, 18:45
Credit: T. Rector and B. Wolpa (NOAO/AURA/NSF)

HST PHAT wide image of M31: This image is 7,900 light-years across and reveals the Andromeda galaxy's crowded central region. The bright area near the centre of the image is a grouping of stars nestled around the galaxy's black hole. The blue dots sprinkled throughout the image are ultra-blue stars whose population increases around the crowded hub. The blue stars are old Sun-like stars that have prematurely cast off their outer layers of material, exposing their extremely blue-hot cores.

Name: Andromeda Galaxy, M 31, Messier 31, NGC 224
Type: Local Universe : Galaxy : Component : Center/Core
Category: Galaxies
Constellation: Andromeda
Release date: 11 January 2012, 19:51
Credit: NASA, ESA, and B. Williams and J. Dalcanton (University of Washington, Seattle)