Spectacular views of V838 Monocerotis light echo: These images show the evolution of the light echo around the star V838 in the constellation of Monoceros. They were taken by the Hubble Advanced Camera for Surveys in November 2005 (left) and again in September 2006 (right). The numerous whorls and eddies in the interstellar dust are particularly noticeable. Possibly they have been produced by the effects of magnetic fields in the space between the stars.

Name: V838 Mon
Type: Milky Way : Star : Type : Variable : NovaMilky Way : Nebula : Appearance : Reflection : Light Echo
Category: NebulaeStars
Distance: 20000 light years
Release date: 26 October 2006, 18:00
Credit: NASA, ESA and H. Bond (STScI)

Spectacular view of V838 Monocerotis light echo: The light echo around the star V838 Monocerotis as seen by the Hubble Space Telescope in November 2005.

Name: V838 Mon
Type: Milky Way : Star : Type : Variable : NovaMilky Way : Nebula : Appearance : Reflection : Light Echo
Category: Nebulae
Constellation: Monoceros
Distance: 20000 light years
Release date: 26 October 2006, 18:00
Credit: NASA, ESA and H. Bond (STScI )

Spectacular view of V838 Monocerotis light echo: The light echo around the star V838 Monocerotis as seen by the Hubble Space Telescope in September 2006.

Name: V838 Mon
Type: Milky Way : Star : Type : Variable : NovaMilky Way : Nebula : Appearance : Reflection : Light Echo
Category: Nebulae
Constellation: Monoceros
Distance: 20000 light years
Release date: 26 October 2006, 18:00
Credit: NASA, ESA and H. Bond (STScI )

Star on a Hubble diet: The star cluster Pismis 24 lies in the core of the large emission nebula NGC 6357 that extends one degree on the sky in the direction of the Scorpius constellation. Part of the nebula is ionised by the youngest (bluest) heavy stars in Pismis 24. The intense ultraviolet radiation from the blazing stars heats the gas surrounding the cluster and creates a bubble in NGC 6357. The presence of these surrounding gas clouds makes probing into the region even harder. One of the top candidates for the title of "Milky Way stellar heavyweight champion" was, until now, Pismis 24-1, a bright young star that lies in the core of the small open star cluster Pismis 24 (the bright stars in the Hubble image) about 8,000 light-years away from Earth. Pismis 24-1 was thought to have an incredibly large mass of 200 to 300 solar masses. New NASA/ESA Hubble measurements of the star, have, however, resolved Pismis 24-1 into two separate stars, and, in doing so, have "halved" its mass to around 100 solar masses.

Name: Pismis 24, Pismis 24-1
Type: Milky Way : Star : Grouping : Cluster
Category: NebulaeStar Clusters
Constellation: Scorpius
Distance: 8000 light years
Release date: 11 December 2006, 19:30
Credit: NASA, ESA and Jesús Maíz Apellániz (Instituto de Astrofísica de Andalucía, Spain). Acknowledgement: Davide De Martin (ESA/Hubble)

Star on a Hubble diet: Left: ACS WFC image of NGC 6357 with Pismis 24-1 in the centre (the brightest star). Middle: Looking closer at Pismis 24-1 with Hubble's ACS High Resolution Channel it becomes clear that it is in reality two stars.Right: ACS HRC image close-up showing the two stars of Pismis 24-1. It  was thought to have an incredibly large mass of 200 to 300 solar masses. New NASA/ESA Hubble measurements of the star, have, however, resolved Pismis 24-1 into two separate stars, and, in doing so, have "halved" its mass to around 100 solar masses.

Name: Cl Pismis 24, Pismis 24, Pismis 24-1
Type: Milky Way : Star : Grouping : Cluster
Category: Star Clusters
Distance: 8000 light years
Release date: 11 December 2006, 19:30
Credit: NASA, ESA and Jesœs Ma­z Apellÿniz (Instituto de astrof­sica de Andaluc­a, Spain). Acknowledgement: Davide De Martin (ESA/Hubble)

Star on a Hubble diet: Looking closer at Pismis 24-1 with Hubble's ACS High Resolution Channel: it becomes clear that it is in reality two stars.

Name: Cl Pismis 24, Pismis 24, Pismis 24-1
Type: Milky Way : Star : Grouping : Cluster
Category: Star Clusters
Constellation: Scorpius
Distance: 8000 light years
Release date: 11 December 2006, 19:30
Credit: NASA, ESA and Jesœs Ma­z Apellÿniz (Instituto de astrof­sica de Andaluc­a, Spain). Acknowledgement: Davide De Martin (ESA/Hubble )

Star on a Hubble diet: ACS HRC image close-up showing the two stars of Pismis 24-1. It  was thought to have an incredibly large mass of 200 to 300 solar masses. New NASA/ESA Hubble measurements of the star, have, however, resolved Pismis 24-1 into two separate stars, and, in doing so, have "halved" its mass to around 100 solar masses.

Name: Cl Pismis 24, Pismis 24, Pismis 24-1
Type: Milky Way : Star : Grouping : Cluster
Category: Star Clusters
Constellation: Scorpius
Distance: 8000 light years
Release date: 11 December 2006, 19:30
Credit: NASA, ESA and Jesœs Ma­z Apellÿniz (Instituto de astrof­sica de Andaluc­a, Spain). Acknowledgement: Davide De Martin (ESA/Hubble )

Star on a Hubble diet (ground-based image): Part of the constellation Scorpius centred on NGC 6357 which has star cluster Pismis 24 in its centre.  This image is a colour composite taken by the Digitized Sky Survey (DSS), the field of view is 3.8x3.3 degrees.

Name: Cl Pismis 24, Pismis 24, Pismis 24-1
Type: Milky Way : Star : Grouping : Cluster
Category: Star Clusters
Constellation: Scorpius
Distance: 8000 light years
Release date: 11 December 2006, 19:30
Credit: Davide De Martin (ESA/Hubble), the ESA/ESO/NASA Photoshop FITS Liberator & Digitized Sky Survey 2

Star on a Hubble diet (ground-based image): Part of the constellation Scorpius centred on NGC 6357 which has star cluster Pismis 24 in its centre.  This image is a colour composite taken by the Digitized Sky Survey (DSS), the field of view is 3.8x3.3 degrees.

Name: Cl Pismis 24, Pismis 24, Pismis 24-1
Type: Milky Way : Star : Grouping : Cluster
Category: Star Clusters
Constellation: Scorpius
Distance: 8000 light years
Release date: 11 December 2006, 19:30
Credit: Davide De Martin (ESA/Hubble), the ESA/ESO/NASA Photoshop FITS Liberator & Digitized Sky Survey 2

Large scale structure of normal matter: The distribution of normal matter in the COSMOS survey was determined mainly by the European Space Agency's XMM/Newton telescope. The brightness of clumps corresponds to the density of normal matter. The map covers an area of sky nine times the angular diameter of the full Moon. By comparing with the dark matter distribution the map demonstrates how normal matter - including stars, galaxies and gas - is built inside an underlying scaffolding of dark matter. The comparison of dark matter and normal matter will provide critical observational underpinnings to future theories for how structure formed in the evolving Universe under the relentless pull of gravity.

Name: COSMOS
Type: Early Universe : Cosmology : Morphology : Large-Scale Structure
Category: Cosmology
Constellation: Sextans
Release date: 7 January 2007, 19:30
Credit: NASA, ESA and R. Massey (California Institute of Technology)