Planetary Host Star: HST ACS/HRC B, V, I composite of microlensing target OGLE-2003-BLG-235/MOA-2003-BLG-53.

Name: MOA 2003-BLG-53, OGLE-2003-BLG-235L
Type: Milky Way : Star : Circumstellar Material : Planetary System
Category: ExoplanetsMiscellaneousStars
Constellation: Sagittarius
Release date: 8 August 2006, 19:00
Credit: NASA, ESA, D. Bennett (University of Notre Dame), and J. Anderson (Rice University)

Identification of extrasolar planet host star: [bottom left text]Hubble Space telescope observed and identified the host star to a gravitationally lensed planet first discovered in 2003 by ground-based telescopes. [left box]A foreground red star and planet drifts toward the sky position of a much farther sunlike background star. [middle-boxes]In 2003, the foreground star-planet system slightly amplifies the light of a background star that momentarily aligns with it. This is called a microlensing event. [right box]The light from each star is progressively more offset year after year as the foreground star drifts by. [bottom right box]In 2005, Hubble Space Telescope observations distinguished the light from the two stars. This was possible because the foreground star turns out to be a different colour from the background star. By observing the stars though a red and blue filter, astronomers were able to enhance the visibility of the offset. The relative offset is 0.7 milliarcseconds (the angular width of a dime seen 3,000 miles away) from the source star. (This is below Hubble's resolution, but still a measurable effect.) The deduced positions of the two stars in 2005 are shown with red and blue crosshatches.

Name: MOA 2003-BLG-53, OGLE-2003-BLG-235L
Type: Milky Way : StarMilky Way : Star : Circumstellar Material : Planetary System
Category: Exoplanets
Release date: 8 August 2006, 19:00
Credit: NASA, ESA, D. Bennett (University of Notre Dame), and J. Anderson (Rice University)

Visible-light and x-ray composite image of galaxy cluster 1E 0657-556: This composite image shows the galaxy cluster 1E 0657-556, also known as the "bullet cluster." This cluster was formed after the collision of two large clusters of galaxies, the most energetic event known in the universe since the Big Bang. Hot gas detected by Chandra in X-rays is seen as two pink clumps in the image and contains most of the "normal," or baryonic, matter in the two clusters. The bullet-shaped clump on the right is the hot gas from one cluster, which passed through the hot gas from the other larger cluster during the collision. An optical image from Magellan and the Hubble Space Telescope shows the galaxies in orange and white. The blue areas in this image depict where astronomers find most of the mass in the clusters. The concentration of mass is determined by analyzing the effect of so-called gravitational lensing, where light from the distant objects is distorted by intervening matter. Most of the matter in the clusters (blue) is clearly separate from the normal matter (pink), giving direct evidence that nearly all of the matter in the clusters is dark. The hot gas in each cluster was slowed by a drag force, similar to air resistance, during the collision. In contrast, the dark matter was not slowed by the impact because it does not interact directly with itself or the gas except through gravity. Therefore, during the collision the dark matter clumps from the two clusters moved ahead of the hot gas, producing the separation of the dark and normal matter seen in the image. If hot gas was the most massive component in the clusters, as proposed by alternative theories of gravity, such an effect would not be seen. Instead, this result shows that dark matter is required. Comparing the optical image with the blue emission shows that the most of the galaxies in each cluster are located near the two dark matter clumps. This shows that the galaxies in each cluster did not slow down because of the collision, unlike the hot gas.

Name: 1ES 0657-55.8
Type: Local Universe : Galaxy : Grouping : Cluster
Category: Galaxies
Constellation: Carina
Release date: 1 November 2012, 23:03
Credit: X-ray: NASA/CXC/M.Markevitch et al.Optical: NASA/STScI; Magellan/U.Arizona/D.Clowe et al.Lensing Map: NASA/STScI; ESO WFI; Magellan/U.Arizona/D.Clowe et al.

N 180B in the Large Magellanic Cloud: This active region of star formation in the Large Magellanic Cloud (LMC), as photographed by NASA/ESA Hubble Space Telescope, unveils wispy clouds of hydrogen and oxygen that swirl and mix with dust on a canvas of astronomical size. The LMC is a satellite galaxy of the Milky Way. This particular region within the LMC, referred to as N 180B, contains some of the brightest known star clusters. The hottest blue stars can be brighter than a million of our Suns. Their intense energy output generates not only harsh ultraviolet radiation but also incredibly strong stellar "winds" of high-speed, charged particles that blow into space. The ultraviolet radiation ionizes the interstellar gas and makes it glow, while the winds can disperse the interstellar gas across tens or hundreds of light-years. Both actions are evident in N 180B. Also visible etched against the glowing hydrogen and oxygen gases are 100 light-year-long dust streamers that run the length of the nebula, intersecting the core of the cluster near the centre of the image. Perpendicular to the direction of the dark streamers, bright orange rims of compact dust clouds appear near the bottom right of and top left corners of the image. These dark concentrations are on the order of a few light-years in size. Also visible among the dust clouds are so-called "elephant trunk" stalks of dust. If the pressure from the nearby stellar winds is great enough to compress this material and cause it to gravitationally contract, star formation might be triggered in these small dust clouds. These dust clouds are evidence that this is still a young star-formation region. This image was taken with Hubble's Wide Field Planetary Camera 2 in 1998 using filters that isolate light emitted by hydrogen and oxygen gas. To create a colour composite, the data from the hydrogen filter were colorized red, the oxygen filter were colorized blue, and a combination of the two filters averaged together was colorized green. The amalgamation yields pink and orange hydrogen clouds set amid a field of soft blue oxygen gas. Dense dust clouds block starlight and glowing gas from our view point.

Name: LH 117, N 180B, NGC 2122
Type: Milky Way : Nebula : Type : Star Formation
Category: Nebulae
Constellation: Mensa
Release date: 23 August 2006, 15:00
Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

Uranus as Viewed from Earth - 1994, 1997, 2006: This NASA Hubble Space Telescope image is a never-before-seen astronomical alignment of a moon traversing the face of Uranus, and its accompanying shadow. The white dot near the center of Uranus’ blue-green disk is the icy moon Ariel.

Name: Ariel, Uranus
Type: Solar System : PlanetSolar System : Planet : Satellite
Category: Solar System
Release date: 31 August 2006, 19:00
Credit: NASA, ESA, L. Sromovsky (University of Wisconsin, Madison), H. Hammel (Space Science Institute), and K. Rages (SETI)

Composite Image of Galaxy Cluster MS 0735: This is a new composite image of galaxy cluster MS0735.6+7421, located about 2.6 billion light-years away in the constellation Camelopardalis. The three views of the region were taken with NASA's Hubble Space Telescope in Feb. 2006, NASA's Chandra X-ray Observatory in Nov. 2003, and NRAO's Very Large Array in Oct. 2004.

Name: MS 0735.6+742
Type: Early Universe : Galaxy : Grouping : Cluster
Category: Galaxies
Constellation: Camelopardalis
Distance: z=0.216 (redshift)
Release date: 2 November 2006, 19:00
Credit: Hubble and Chandra: NASA, ESA, CXC, STScI, and B. McNamara (University of Waterloo) Very Large Array Telescope Image Credit: NRAO, and L. Birzan and team (Ohio University)