Posts tagged astronomy.

Crab Nebula's Pulsar May Be Fast Particle Accelerator ›

“The Crab Nebula (also designated M1 or NGC 1952) is visible through small telescopes, which has allowed astronomers to observe its growth and evolution since the supernovae that created it became visible in 1054 CE. A pulsar was found in the center of the Crab in 1968. This rapidly rotating neutron star is the core of the star that went supernova to make the nebula. In the intervening decades, x-ray, gamma ray, and radio observations have mapped the region of the nebula closest to the pulsar. During that mapping, it became apparent that the Crab pulsar is one of the brightest sources of gamma rays observable from Earth.

Despite all of those observations, we still don’t fully understand the Crab’s precise gamma ray spectrum, particularly recently observed pulses of intense gamma radiation seen by the Fermi Gamma-ray Space Telescope. Existing models certainly do well at describing much of the complex interplay between the intense magnetic fields of the pulsar and the winds of charged particles flowing outward. But no single scheme seems sufficient to cover all the observed phenomena.

A potentially promising new model, proposed by F. A. Aharonian, S. V. Bogovalov, and D. Khangulyan, may fill in some of these blanks. It proposes that areas near the pulsar are acting as rapid particle accelerators, but don’t boost electrons and heavier particles to the same extent.”

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BBC News - Distant 'waterworld' is confirmed ›

Astronomers have confirmed the existence of a new class of planet: a waterworld with a thick, steamy atmosphere.

The exoplanet GJ 1214b is a so-called “Super Earth” - bigger than our planet, but smaller than gas giants such as Jupiter. Observations using the Hubble telescope now seem to confirm that a large fraction of its mass is water. The planet’s high temperatures suggest exotic materials might exist there.

“GJ 1214b is like no planet we know of,” said lead author Zachory Berta, from the Harvard Smithsonian Center for Astrophysics.

sisterspock:

NASA’s Solar Dynamics Observatory (SDO) captured these images of a partial eclipse.

Rare Element, Tellurium, Detected for the First Time in Ancient Stars

“The researchers found traces of this brittle, semiconducting element — which is very rare on Earth — in stars that are nearly 12 billion years old. The finding supports the theory that tellurium, along with even heavier elements in the periodic table, likely originated from a very rare type of supernova during a rapid process of nuclear fusion. The researchers published their findings online in Astrophysical Journal Letters.”

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(via parkstepp)

ryanfarkas:

The Solar System Represented Across 6000 Pages

moderation:

Planck All-Sky Images Show Cold Gas and Strange Haze

New images from the Planck mission show previously undiscovered islands of star formation and a mysterious haze of microwave emissions in our Milky Way galaxy. The views give scientists new treasures to mine and take them closer to understanding the secrets of our galaxy.

Planck is a European Space Agency mission with significant NASA participation.

“The images reveal two exciting aspects of the galaxy in which we live,” said Planck scientist Krzysztof M. Gorski from NASA’s Jet Propulsion Laboratory in Pasadena, Calif., and Warsaw University Observatory in Poland. “They show a haze around the center of the galaxy, and cold gas where we never saw it before.”

The new images show the entire sky, dominated by the murky band of our Milky Way galaxy. One of them shows the unexplained haze of microwave light previously hinted at in measurements by NASA’s Wilkinson Microwave Anisotropy Probe (WMAP).

“The haze comes from the region surrounding the center of our galaxy and looks like a form of light energy produced when electrons accelerate through magnetic fields,” said Davide Pietrobon, another JPL Planck scientist.

“We’re puzzled though, because this haze is brighter at shorter wavelengths than similar light emitted elsewhere in the galaxy,” added Gorski.

Several explanations have been proposed for this unusual behaviour.

“Theories include higher numbers of supernovae, galactic winds and even the annihilation of dark-matter particles,” said Greg Dobler, a Planck collaborator from the University of California in Santa Barbara, Calif. Dark matter makes up about a quarter of our universe, but scientists don’t know exactly what it is.

(via NASA)

ikenbot:

Odd Black Hole Is Last Survivor of Its Galaxy

The Hubble space telescope has spotted a supermassive black hole floating on the outskirts of a large galaxy.

The location is odd because black holes of this size generally form in the centers of galaxies, not at their edges. This suggests the black hole is the lone survivor of a now-disintegrated dwarf galaxy.

The black hole — named HLX-1 — is 20,000 times more massive than the sun, and is situated 290 million light-years away at the edge of the spiral galaxy ESO 243-49.

Hubble detected a great deal of energetic blue light coming from the black hole’s accretion disk — a massive collection of gas and dust that spirals into the black hole’s maw, generating x-rays. But scientists studying Hubble’s data also noticed the presence of cooler, red light, which shouldn’t have been there.

Astronomers suspect the red light indicates the existence of a cluster of young stars, roughly 200 million years old, orbiting around the black hole. These stars, in turn, are the key to explaining the chaotic history of the supermassive black hole.

HLX-1 was likely formed at the center of a dwarf galaxy that once orbited ESO 243-49. But in this dog-eat-dog universe of ours, large galaxies often swallow up their smaller brethren. When the dwarf galaxy came too close to ESO 243-49, the larger galaxy plucked away most of its stars, leaving behind the exposed central black hole.

The force of the galaxies’ collision would have also triggered the formation of new stars, explaining the presence of a young stellar cluster around the black hole. The cluster’s age, 200 million years, gives a good estimate of when the merger occurred.

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Journal Reference: Astrophysical Journal

(via kenobi-wan-obi)

(via sisterspock)

#sun  #astronomy  

BBC News - Vega rocket set for maiden voyage ›

The 30m-tall vehicle, first conceived in the 1990s, will launch on what is termed a qualification flight from the Kourou spaceport in French Guiana. It will carry nine satellites into orbit but the object of the mission is really to prove the rocket’s systems all work as designed.

Rare Martian meteorite lands at Natural History Museum ›

“The piece of the Tissint meteorite, about the size of a paperback book, is the largest and newest known and could help determine whether there is life on the planet. The meteorite fell as a shower of stones in the desert of southern Morocco last July.”

iliveinaspiralgalaxy:

Sunspot Loops in Ultraviolet by Image Editor on Flickr.

sisterspock:

This simulation shows the future behaviour of a gas cloud that has been observed approaching the supermassive black hole at the centre of the Milky Way. This is the first time ever that the approach of such a doomed cloud to a supermassive black hole has been observed and it is expected to break up completely during 2013.

ikenbot:

In The Heart Of Cygnus, NASA’s Fermi Reveals A Cosmic-ray Cocoon

The constellation Cygnus, now visible in the western sky as twilight deepens after sunset, hosts one of our galaxy’s richest-known stellar construction zones.

Astronomers viewing the region at visible wavelengths see only hints of this spectacular activity thanks to a veil of nearby dust clouds forming the Great Rift, a dark lane that splits the Milky Way, a faint band of light marking our galaxy’s central plane.

(via kenobi-wan-obi)

universalnomad:

Exoplanets in the Solar Neighborhood out to 65 ly.

(via theweirdthewonderful)

The Scale of the Universe ›

This is fantastic.