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Hubble Finds a Star Eating a Planet

Copyright NASA

The hottest known planet in the Milky Way galaxy may also be its shortest-lived world. The doomed planet is being eaten by its parent star, according to observations made by a new instrument on NASA’s Hubble Space Telescope, the Cosmic Origins Spectrograph (COS). The planet may only have another 10 million years left before it is completely devoured.

The planet, called WASP-12b, is so close to its sunlike star that it is superheated to nearly 2,800 degrees Fahrenheit and stretched into a football shape by enormous tidal forces. The atmosphere has ballooned to nearly three times Jupiter’s radius and is spilling material onto the star. The planet is 40 percent more massive than Jupiter.

This effect of matter exchange between two stellar objects is commonly seen in close binary star systems, but this is the first time it has been seen so clearly for a planet.

“We see a huge cloud of material around the planet, which is escaping and will be captured by the star. We have identified chemical elements never before seen on planets outside our own solar system,” says team leader Carole Haswell of The Open University in Great Britain.

Haswell and her science [...]

Astronomers Discover New Star-Forming Regions

Copyright NASA

Astronomers studying the Milky Way have discovered a large number of previously unknown regions where massive stars are being formed. Their discovery, made with the help of NASA’s Spitzer Space Telescope, provides important new information about the structure of our home galaxy and promises to yield new clues about its composition. The star-forming regions the astronomers sought, called H II regions, are sites where hydrogen atoms are stripped of their electrons by intense radiation from massive, young stars. To find these regions, hidden from visible-light detection by the Milky Way’s gas and dust, the researchers used infrared and radio telescopes. “We found our targets by using the results of infrared surveys done with NASA’s Spitzer Space Telescope and of surveys done with the National Science Foundation’s Very Large Array radio telescope,” said astronomer Loren Anderson of the Astrophysical Laboratory of Marseille in France, who worked on the project. “Objects that appear bright in both the Spitzer and Very Large Array images we studied are good candidates for H II regions.” Further analysis allowed the astronomers to determine the locations of the H II regions. They found concentrations of the regions at the end of the galaxy’s central [...]

Planck highlights the complexity of star formation

Copyright ESA

New images from ESA’s Planck space observatory reveal the forces driving star formation and give astronomers a way to understand the complex physics that shape the dust and gas in our Galaxy.

Star formation takes place hidden behind veils of dust but that doesn’t mean we can’t see through them. Where optical telescopes see only black space, Planck’s microwave eyes reveal myriad glowing structures of dust and gas. Now, Planck has used this ability to probe two relatively nearby star-forming regions in our Galaxy.

The Orion region is a cradle of star formation, some 1500 light-years away. It is famous for the Orion Nebula, which can be seen by the naked eye as a faint smudge of pink.

Planck image of a region in the constellation Perseus The first image covers much of the constellation of Orion. The nebula is the bright spot to the lower centre. The bright spot to the right of centre is around the Horsehead Nebula, so called because at high magnifications a pillar of dust resembles a horse’s head.

The giant red arc of Barnard’s Loop is thought to be the blast wave from a star that blew up inside the [...]

Planck sees tapestry of cold dust

Giant filaments of cold dust stretching through our Galaxy are revealed in a new image from ESA’s Planck satellite. Analysing these structures could help to determine the forces that shape our Galaxy and trigger star formation.

Planck is principally designed to study the biggest mysteries of cosmology. How did the Universe form? How did the galaxies form? This new image extends the range of its investigations into the cold dust structures of our own Galaxy.

The image shows the filamentary structure of dust in the solar neighbourhood – within about 500 light-years of the Sun. The local filaments are connected to the Milky Way, which is the pink horizontal feature near the bottom of the image. Here, the emission is coming from much further away, across the disc of our Galaxy. The image has been colour coded to discern different temperatures of dust. White-pink tones show dust of a few tens of degrees above absolute zero, whereas the deeper colours are dust at around –261°C, only about 12 degrees above absolute zero. The warmer dust is concentrated into the plane of the Galaxy whereas the dust suspended above and below is cooler.

“What makes these structures have these [...]

Herschel views deep-space pearls on a cosmic string

Herschel views deep-space pearls on a cosmic string

Copyright ESA

Herschel has delivered spectacular vistas of cold gas clouds lying near the plane of the Milky Way, revealing intense, unexpected activity. The dark, cool region is dotted with stellar factories, like pearls on a cosmic string.

On 3 September, Herschel aimed its telescope at a reservoir of cold gas in the constellation of the Southern Cross near the Galactic Plane. As the telescope scanned the sky, the spacecraft’s Spectral and Photometric Imaging REceiver, SPIRE, and Photoconductor Array Camera and Spectrometer, PACS instruments snapped the pictures. The region is located about 60° from the Galactic Centre, thousands of light-years from Earth.

The five original infrared wavelengths have been colour-coded to allow scientists to differentiate extremely cold material (red) from the surrounding, slightly warmer stuff (blue).

The images reveal structure in cold material in our Galaxy, as we have never seen it before, and even before a detailed analysis, scientists have gleaned information on the quantity of the material, its mass, temperature, composition and whether it is collapsing to form new stars.

That a dark, cool area such as this would be bustling with activity, was unexpected. But the images reveal a surprising amount of turmoil: the interstellar material [...]

AKARI presents detailed all-sky map in infrared light

akari-presents-detailed-all-sky-map-in-infrared-light

Copyright ESA

One year after the beginning of its scientific operations, the high-capability infrared satellite AKARI continues to produce stunning views of the infrared Universe.

Launched in February 2006, AKARI is making a comprehensive, multi-wavelength study of the sky in infrared light, helping to gain a deeper understanding of the formation and evolution of galaxies, stars and planetary systems. The mission is a Japan Aerospace Exploration Agency (JAXA) project with ESA and international participation.

In the course of last year, AKARI performed all-sky observations in six wavelength bands. More than 90 percent of the entire sky has so far been imaged. The mission provides the first census of the infrared sky since the atlas made by its only infrared surveyor predecessor, the Anglo-Dutch-US IRAS satellite more than 20 years ago. AKARI has studied about 3500 selected targets during pointed observations, with improved spatial resolution.

The latest results presented by JAXA today show the infrared sky with unprecedented spatial resolution and wavelength coverage and, in particular, many regions of active star formation.

The first two images presented in this article show the entire sky in infrared light at nine micrometres. The bright stripe extending from left to right is the disc [...]

Theft of a million stars

theft-of-a-million-stars

Copyright ESA

Using ESO’s Very Large Telescope, a team of Italian astronomers reveal the troubled past of the stellar cluster Messier 12 – our Milky Way galaxy ‘stole’ close to one million low-mass stars from it.

Globular clusters move in extended elliptical orbits that periodically take them through the densely populated regions of our galaxy, and then high above and below the plane (the ‘halo’).

When venturing too close to the innermost dense regions of our galaxy, (the ‘bulge’), a globular cluster can be perturbed and its smallest stars ripped away.

The astronomers, led by Guido De Marchi of the European Space Agency, measured the brightness and colours of more than 16 000 stars within the Messier 12 cluster with one of the Unit Telescopes of ESO’s VLT at Cerro Paranal in Chile. The team could study stars that are 50 million times fainter than those seen with the unaided eye.

Messier 12

Central part of Messier 12 as seen by the ESO telescope “In the solar neighbourhood and in most stellar clusters, the least massive stars are by far the most common. But our observations with the VLT show this is not the case for Messier 12,” said De [...]

Black hole without a home

black-hole-without-a-home

Copyright ESA

The detection of a super-massive black hole without a massive ‘host’ galaxy is the surprising result from a large Hubble and VLT study of quasars.

This is the first convincing discovery of such an object. One intriguing explanation is that the host galaxy may be made almost exclusively of ‘dark matter’.

A team of European astronomers has used two of the most powerful astronomical facilities available, the NASA/ESA Hubble Space Telescope and the ESO Very Large Telescope (VLT) at Cerro Paranal, to discover a bright quasar without a massive host galaxy.

Quasars are powerful and typically very distant source of huge amounts of radiation. They are commonly associated with galaxies containing an active central black hole.

The team conducted a detailed study of 20 relatively nearby quasars. For 19 of them, they found, as expected, that these super-massive black holes are surrounded by a host galaxy. But when they studied the bright quasar HE0450-2958, located some 5000 million light-years away, they could not find evidence for a host galaxy.

The astronomers suggest that this may indicate a rare case of a collision between a seemingly normal spiral galaxy and an ‘exotic’ object harbouring a very massive black hole.

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