Merging clusters in 30 Doradus: This is a Hubble Space Telescope image of a pair of star clusters  that are  believed to be in the early stages of merging. The clusters  lie in the  gigantic 30 Doradus Nebula, which is 170,000 light-years  from Earth. Hubble's circumstantial evidence for the impending collision comes   from seeing an elongated structure in the cluster at upper left, and   from measuring a different age between the two clusters. Also, the   unusually large number  of high-velocity stars around 30 Doradus can  finally be explained if a  small cluster has merged into the big cluster  R136 in the centre of the  Tarantula Nebula. This nearby example of cluster interaction yields insights into how star  clusters may have formed in the early Universe. The Hubble observations, made with the Wide Field Camera 3, were  taken  20-27 October, 2009. The blue colour is light from the hottest, most  massive  stars; the green from the glow of oxygen; and the red from  fluorescing  hydrogen.

Name: 30 Dor, 30 Doradus, 30 Doradus Nebula, Tarantula Nebula
Type: Local Universe : Nebula : Type : Star Formation
Category: Nebulae
Constellation: Dorado
Distance: 170000 light years
Release date: 20 August 2012, 17:11
Credit: NASA, ESA, and E. Sabbi (ESA/STScI) Acknowledgment: R. O'Connell (University of Virginia) and the  Wide Field Camera 3 Science Oversight Committee

A multi-wavelength view of radio galaxy Hercules A: Spectacular jets powered by the gravitational energy of a supermassive black hole in the core of the elliptical galaxy Hercules A illustrate the combined imaging power of two of astronomy's cutting-edge tools, the Hubble Space Telescope's Wide Field Camera 3, and the recently upgraded Karl G. Jansky Very Large Array (VLA) radio telescope in New Mexico. Some two billion light-years away, the yellowish elliptical galaxy in the centre of the image appears quite ordinary as seen by Hubble in visible wavelengths of light. The galaxy is roughly 1000 times more massive than the Milky Way and harbors a 2.5-billion-solar-mass central black hole that is 1000 times more massive than the black hole in the Milky Way. But the innocuous-looking galaxy, also known as 3C 348, has long been known as the brightest radio-emitting object in the constellation Hercules. Emitting nearly a billion times more power in radio wavelengths than our Sun, the galaxy is one of the brightest extragalactic radio sources in the entire sky. The VLA radio data reveal enormous, optically invisible jets that, at one-and-a-half million light-years wide, dwarf the visible galaxy from which they emerge. The jets are very-high-energy plasma beams, subatomic particles and magnetic fields shot at nearly the speed of light from the vicinity of the black hole. The outer portions of both jets show unusual ring-like structures suggesting a history of multiple outbursts from the supermassive black hole at the centre of the galaxy. The innermost parts of the jets are not visible because of the extreme velocity of the material, which causes relativistic effects that beam the light away from us. Far from the galaxy, the jets become unstable and break up into the rings and wisps. The entire radio source is surrounded by a very hot, X-ray-emitting cloud of gas, not seen in this optical-radio composite. Hubble's view of the field also shows a companion elliptical galaxy very close to the centre of the optical-radio source, which may be merging with the central galaxy. Several other elliptical and spiral galaxies that are visible in the Hubble data may be members of a cluster of galaxies. Hercules A is by far the brightest and most massive galaxy in the cluster.

Name: Hercules A
Type: Local Universe : Galaxy : Activity : AGN
Category: Galaxies
Constellation: Hercules
Distance: z=0.156 (redshift)
Release date: 4 December 2012, 13:40
Credit: NASA, ESA, S. Baum and C. O'Dea (RIT), R. Perley and W. Cotton (NRAO/AUI/NSF), and the Hubble Heritage Team (STScI/AURA)

Rogue planetary orbit for Fomalhaut b: This false-colour composite image, taken with the Hubble Space Telescope, reveals the orbital motion of the planet Fomalhaut b. Based on these observations, astronomers calculated that the planet is in a 2000-year-long, highly elliptical orbit. The planet will appear to cross a vast belt of debris around the star roughly 20 years from now. If the planet's orbit lies in the same plane with the belt, icy and rocky debris in the belt could crash into the planet's atmosphere and produce various phenomena. The black circle at the centre of the image blocks out the light from the bright star, allowing reflected light from the belt and planet to be photographed. The Hubble images were taken with the Space Telescope Imaging Spectrograph in 2010 and 2012.

Name: Fomalhaut b
Type: Milky Way : Star : Circumstellar Material : Planetary System
Category: ExoplanetsStars
Release date: 22 January 2013, 11:26
Credit: NASA, ESA and P. Kalas (University of California, Berkeley and SETI Institute)

Fomalhaut system: Fomalhaut system.

Name: Fomalhaut, Fomalhaut b
Type: Milky Way : Star : Circumstellar Material : Planetary System
Category: ExoplanetsStars
Release date: 22 January 2013, 11:30
Credit: NASA, ESA and P. Kalas (University of California, Berkeley, USA)

Compass and scale image for Fomalhaut b: Compass and scale image for Fomalhaut b.

Name: Fomalhaut b
Type: Milky Way : Star : Circumstellar Material : Planetary System
Category: ExoplanetsStars
Release date: 22 January 2013, 11:51
Credit: Illustration Credit: NASA, ESA and Z. Levay (STScI)Science Credit: NASA, ESA and P. Kalas (University of California, Berkeley, USA)