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Supermassive black holes common in early  Universe

...observations of a spectacular collision of galaxies in the distant Universe have revealed that colossal black holes were present when galaxies were just beginning to form...

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Fermi discovers first pure gammar ray pulsar

...the Fermi spacecraft’s Large Area Telescope has discovered the first pure gamma ray-only stellar corpse, blinking at the Earth around three times a second...

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Martian moon Phobos a rubble pile? Mars Express observations of Martian moon Phobos suggest it could be a rubble pile rather than a single solid object..

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Video archive

STS-120 day 2 highlights

Flight Day 2 of Discovery's mission focused on heat shield inspections. This movie shows the day's highlights.


STS-120 day 1 highlights

The highlights from shuttle Discovery's launch day are packaged into this movie.


STS-118: Highlights

The STS-118 crew, including Barbara Morgan, narrates its mission highlights film and answers questions in this post-flight presentation.

 Full presentation
 Mission film

STS-120: Rollout to pad

Space shuttle Discovery rolls out of the Vehicle Assembly Building and travels to launch pad 39A for its STS-120 mission.


Dawn leaves Earth

NASA's Dawn space probe launches aboard a Delta 2-Heavy rocket from Cape Canaveral to explore two worlds in the asteroid belt.

 Full coverage

Dawn: Launch preview

These briefings preview the launch and science objectives of NASA's Dawn asteroid orbiter.

 Launch | Science

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The stellar nursery with a massive heart

Posted: October 22, 2008

A new ESO image reveals the vast stellar nursery of Gum 29, which hosts a small cluster of stars bearing one of the most massive double star systems known to man.

This image was obtained with the Wide Field Imager (WFI) camera attached to the 2.2-metre Max-Planck/ESO telescope through four different filters (B, V, R, and H-alpha), and shows the amazing intricacies of the vast stellar nursery Gum 29. At its centre lies the cluster of young stars Westerlund 2. Image: ESO.

Gum 29, named for it being the 29th entry in astronomer Colin Stanley Gum’s catalogue, is a vast region of ionised hydrogen gas that spans over 200 light years. Known as the H-II region, the hydrogen gas has been stripped of its electrons by the intense breath of hot young stars radiating in its centre. The new image was captured with the Wide Field Imager (WFI) camera attached to the 2.2 metre Max-Planck telescope at the European Southern Observatory (ESO)’s La Silla site in Chile.

A young and little-known star cluster – Westerlund 2 – is embedded within the belly of Gum 29 at a distance of 26,000 light years from Earth, corresponding to a location within the outer edge of the Carina spiral arm of our Milky Way Galaxy. It is thought to be just one or two million years old. Two stars in the bottom right of Westerlund 2 form a double star system of huge proportions at 82 and 83 times the mass of our Sun respectively, and rotating around each other in approximately 3.7 days. They are amongst the most massive stars known to astronomers.

Marked in the image is a double stellar system in the Westerlund 2 cluster. The two stars have masses of 82 and 83 times that of our Sun and are amongst the most massive stars known to astronomers. Image: ESO.

Intense scrutiny of this pair has also revealed their identity as Wolf-Rayet stars, massive stars that are expelling huge quantities of material as they near the end of their lives. Observations made in X-rays have subsequently shown that streams of material from each star continually collide, creating a blaze of X-ray radiation.