Observations by the NASA/ESA Hubble Space Telescope have come up with a new class of planet, a waterworld enshrouded by a thick, steamy atmosphere. It's smaller than Uranus but larger than Earth.(author unknown)

The moon has been cooling and shrinking since its formation billions of years ago, but new images reveal that parts of it have recently been stretching too

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Astronomers confirm the existence of a new class of planet - a "water-world" with a thick, steamy atmosphere.(author unknown)

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Observations of the extrasolar planet GJ1214b by NASA's Hubble Space Telescope have come up with a new class of planet, a waterworld enshrouded by a thick, steamy atmosphere. It's smaller than Uranus but larger than Earth. A paper reporting these results has been accepted for publication in The Astrophysical Journal and is available online.

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New images from NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft show the moon's crust is being stretched, forming minute valleys in a few small areas on the lunar surface.(author unknown)

Few middleweight black holes have been found, and a new study suggests why – they may only shine when they binge after a traumatic event

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Astronomers using NASA's Hubble Space Telescope may have found evidence for a cluster of young, blue stars encircling HLX-1, one of the first intermediate-mass black holes ever discovered. Astronomers believe the black hole may once have been at the core of a now-disintegrated dwarf galaxy. The discovery of the black hole and the possible star cluster has important implications for understanding the evolution of supermassive black holes and galaxies.

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Astronomers using the NASA/ESA Hubble Space Telescope have found a cluster of young blue stars surrounding a mid-sized black hole called HLX-1. The discovery suggests that the black hole formed in the core of a now-disintegrated dwarf galaxy. The findings have important implications for understanding the evolution of supermassive black holes and galaxies.(author unknown)

Globular star clusters are oddly similar – new simulations suggest galaxy mergers destroyed the smaller ones

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Astronomers are watching a delayed broadcast of a spectacular outburst from the unstable, behemoth double-star system Eta Carinae, an event initially seen on Earth nearly 170 years ago. Dubbed the "Great Eruption," the outburst first caught the attention of sky watchers in 1837 and was observed through 1858. But astronomers didn't have sophisticated science instruments to accurately record the star system's petulant activity. Luckily for today's astronomers, some of the light from the eruption took an indirect path to Earth and is just arriving now, providing an opportunity to analyze the outburst in detail. The wayward light was heading in a different direction, away from our planet, when it bounced off dust clouds lingering far from the turbulent stars and was rerouted to Earth, an effect called a "light echo." Because of its longer path, the light reached Earth 170 years later than the light that arrived directly.

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Following a permanent anomaly affecting the onboard solid-state mass memory system on Mars Express, efforts to implement a work-around are almost complete. Full science operations have been resumed and the potential mission lifetime remains unaltered.(author unknown)

Musicians and music-lovers alike are invited to this year’s Cambridge Science Festival – the UK’s biggest free science festival – which runs from March 12-25 at venues across the University and City.(author unknown)

A new image from the APEX (Atacama Pathfinder Experiment) telescope in Chile shows a sinuous filament of cosmic dust more than ten light-years long. In it, newborn stars are hidden, and dense clouds of gas are on the verge of collapsing to form yet more stars. It is one of the regions of star formation closest to us. The cosmic dust grains are so cold that observations at wavelengths of around one millimetre, such as these made with the LABOCA camera on APEX, are needed to detect their faint glow.(author unknown)

Light echoes reveal an unexpectedly cool η Carinae during its nineteenth-century Great Eruption

Nature 482, 7385 (2012). doi:10.1038/nature10775

Authors: A. Rest, J. L. Prieto, N. R. Walborn, N. Smith, F. B. Bianco, R. Chornock, D. L. Welch, D. A. Howell, M. E. Huber, R. J. Foley, W. Fong, B. Sinnott, H. E. Bond, R. C. Smith, I. Toledo, D. Minniti & K. Mandel

η Carinae is one of the most massive binary stars in the Milky Way. It became the second-brightest star in our sky during its mid-nineteenth-century ‘Great Eruption’, but then faded from view (with only naked-eye estimates of brightness). Its eruption is unique in that it exceeded the Eddington luminosity limit for ten years. Because it is only 2.3 kiloparsecs away, spatially resolved studies of the nebula have constrained the ejected mass and velocity, indicating that during its nineteenth-century eruption, η Car ejected more than ten solar masses in an event that released ten per cent of the energy of a typical core-collapse supernova, without destroying the star. Here we report observations of light echoes of η Carinae from the 1838–1858 Great Eruption. Spectra of these light echoes show only absorption lines, which are blueshifted by −210 km s−1, in good agreement with predicted expansion speeds. The light-echo spectra correlate best with those of G2-to-G5 supergiants, which have effective temperatures of around 5,000 kelvin. In contrast to the class of extragalactic outbursts assumed to be analogues of the Great Eruption of η Carinae, the effective temperature of its outburst is significantly lower than that allowed by standard opaque wind models. This indicates that other physical mechanisms such as an energetic blast wave may have triggered and influenced the eruption.

Astrophysics: Echoes from an old outburst

Nature 482, 7385 (2012). doi:10.1038/482317a

Authors: Noam Soker & Amit Kashi

Almost two centuries after the eruption of one of the most massive binary systems in our Galaxy, light reflected from its surroundings has been detected. The observations challenge traditional models for the eruption. See Letter p.375

Telescope's all-sky map hints at where stars are forming(author unknown)

What now for Red Planet exploration?(author unknown)

An unambiguous detection of the Galactic Haze - a mysterious, diffuse emission from the central portion of the Milky Way - and the first all-sky map of carbon monoxide, whose emission traces the molecular clouds where stars are born, are among the results being presented by the Planck Collaboration at an international conference held from 13 to 17 February 2012, in Bologna, Italy. These results have been achieved during the complex task of identifying and removing the foreground contamination due to Galactic and extragalactic emission that obscures the Cosmic Microwave Background.(author unknown)

Earth 2.0 is in our sights. Checking it for signs of life will be the next big issue, says Jill Tarter

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ESA's Venus Express spacecraft has discovered that our cloud-covered neighbour spins a little slower than previously measured. Peering through the dense atmosphere in the infrared, the orbiter found surface features were not quite where they should be.(author unknown)