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Astrophysics: Supernova seen through γ-ray eyes

Astronomy News - 27 August 2014 - 1:00am

Astrophysics: Supernova seen through γ-ray eyes

Nature 512, 7515 (2014). doi:10.1038/512375a

Authors: Robert P. Kirshner

Observations of γ-ray photons from a type Ia supernova indicate that stellar explosions of this kind get their energy from sudden thermonuclear fusion in the progenitor star. See Letter p.406

Neutrinos from the primary proton–proton fusion process in the Sun

Astronomy News - 27 August 2014 - 1:00am

Neutrinos from the primary proton–proton fusion process in the Sun

Nature 512, 7515 (2014). doi:10.1038/nature13702

Authors:

In the core of the Sun, energy is released through sequences of nuclear reactions that convert hydrogen into helium. The primary reaction is thought to be the fusion of two protons with the emission of a low-energy neutrino. These so-called pp neutrinos constitute nearly

Neutrino physics: What makes the Sun shine

Astronomy News - 27 August 2014 - 1:00am

Neutrino physics: What makes the Sun shine

Nature 512, 7515 (2014). doi:10.1038/512378a

Authors: Wick Haxton

Neutrinos produced in the nuclear reaction that triggers solar-energy generation have been detected. This milestone in the search for solar neutrinos required a deep underground detector of exceptional sensitivity. See Article p.383

Cobalt-56 γ-ray emission lines from the type Ia supernova 2014J

Astronomy News - 27 August 2014 - 1:00am

Cobalt-56 γ-ray emission lines from the type Ia supernova 2014J

Nature 512, 7515 (2014). doi:10.1038/nature13672

Authors: E. Churazov, R. Sunyaev, J. Isern, J. Knödlseder, P. Jean, F. Lebrun, N. Chugai, S. Grebenev, E. Bravo, S. Sazonov & M. Renaud

A type Ia supernova is thought to be a thermonuclear explosion of either a single carbon–oxygen white dwarf or a pair of merging white dwarfs. The explosion fuses a large amount of radioactive 56Ni (refs 1–3). After the explosion, the decay chain from 56Ni to 56Co to 56Fe generates γ-ray photons, which are reprocessed in the expanding ejecta and give rise to powerful optical emission. Here we report the detection of 56Co lines at energies of 847 and 1,238 kiloelectronvolts and a γ-ray continuum in the 200–400 kiloelectronvolt band from the type Ia supernova 2014J in the nearby galaxy M82. The line fluxes suggest that about 0.6 ± 0.1 solar masses of radioactive 56Ni were synthesized during the explosion. The line broadening gives a characteristic mass-weighted ejecta expansion velocity of 10,000 ± 3,000 kilometres per second. The observed γ-ray properties are in broad agreement with the canonical model of an explosion of a white dwarf just massive enough to be unstable to gravitational collapse, but do not exclude merger scenarios that fuse comparable amounts of 56Ni.

Evidence for Supernovas Near Earth

Astronomy News - 27 August 2014 - 12:37am
A NASA sounding rocket has confirmed that the solar system is inside an ancient supernova remnant. Life on Earth survived despite the nearby blasts.

Best view yet of merging galaxies in distant Universe [heic1417]

Astronomy News - 26 August 2014 - 5:38pm
Using the NASA/ESA Hubble Space Telescope and many other telescopes on the ground and in space, an international team of astronomers has obtained the best view yet of a collision that took place between two galaxies when the Universe was only half its current age. They enlisted the help of a galaxy-sized magnifying glass to reveal otherwise invisible detail. These new studies of the galaxy H-ATLAS J142935.3-002836 have shown that this complex and distant object looks like the well-known local galaxy collision, the Antennae Galaxies.

Five sites shortlisted for Rosetta's comet landing

Astronomy News - 26 August 2014 - 5:30pm
In orbit around comet 67P/Churyumov-Gerasimenko, the European Space Agency's Rosetta probe has whittled down potential targets for its Philae lander






Best View Yet of Merging Galaxies in Distant Universe

Astronomy News - 26 August 2014 - 5:00pm
Using the Atacama Large Millimeter/submillimeter Array (ALMA), and many other telescopes on the ground and in space, an international team of astronomers has obtained the best view yet of a collision that took place between two galaxies when the Universe was only half its current age. They enlisted the help of a galaxy-sized magnifying glass to reveal otherwise invisible detail. These new studies of the galaxy H-ATLAS J142935.3-002836 have shown that this complex and distant object looks like the well-known local galaxy collision, the Antennae Galaxies.

Candidate Comet Landing Sites Identified

Astronomy News - 26 August 2014 - 3:57pm
The European Space Agency's Rosetta mission has chosen five candidate landing sites on comet 67P/Churyumov-Gerasimenko for its Philae lander. Philae's descent to the comet's nucleus, scheduled for this November, will be the first such landing ever attempted.

XMM-Newton Announcement of Opportunity (AO-14)

Astronomy News - 26 August 2014 - 10:57am
Proposals are solicited for observations with XMM-Newton in response to the fourteenth Announcement of Opportunity, AO-14, issued 26 August 2014. This AO covers the period May 2015 to April 2016 and is open to proposers from all over the world.

New Horizons Crosses the Orbit of Neptune

Astronomy News - 25 August 2014 - 7:05pm
NASA’s Pluto-bound New Horizons spacecraft has traversed the orbit of Neptune. This is its last major crossing en route to becoming the first probe to make a close encounter with distant Pluto on July 14, 2015.

VIDEO: Aurora Borealis filmed from space

Astronomy News - 25 August 2014 - 5:24pm
The European Space Agency releases time-lapse footage of the Aurora Borealis - better known as the Northern Lights - filmed from the International Space Station.

NASA’s New Horizons Spacecraft Crosses Neptune Orbit En Route to Historic Pluto Encounter

Astronomy News - 25 August 2014 - 5:00pm
NASA’s Pluto-bound New Horizons spacecraft has traversed the orbit of Neptune. This is its last major crossing en route to becoming the first probe to make a close encounter with distant Pluto on July 14, 2015.

Potential comet landing sites chosen

Astronomy News - 25 August 2014 - 3:41pm
Europe's Rosetta mission, which aims to put a robot on a comet in November, has identified five potential sites for the touchdown.

Rosetta:Rosetta: Landing site search narrows

Astronomy News - 25 August 2014 - 2:00pm
Using detailed information collected by ESA's Rosetta spacecraft during its first two weeks at Comet 67P/Churyumov-Gerasimenko, five locations have been identified as candidate sites to set down the Philae lander in November – the first time a landing on a comet has ever been attempted.

Hints of elusive early stars found

Astronomy News - 21 August 2014 - 7:33pm
Astronomers may have discovered the chemical signature of one of the Universe's earliest stars.

Earliest stars lived short, fiery lives

Astronomy News - 21 August 2014 - 7:00pm
The chemical fingerprint of an ancient star suggests its predecessors were more massive than thought, ending up as huge supernovae

Rosetta's 10-billion-tonne comet

Astronomy News - 21 August 2014 - 3:06pm
Scientists determine the comet being followed by Europe's Rosetta spacecraft to have a mass of 10 billion tonnes.

Nearby galaxy may be victim of dark matter hit-and-run

Astronomy News - 20 August 2014 - 3:17pm
A massive hole in a small spiral galaxy may have been punched by a huge "subhalo" of dark matter – and the same thing may have happened to the Milky Way






A Spectacular Landscape of Star Formation

Astronomy News - 20 August 2014 - 11:00am
This image, captured by the Wide Field Imager at ESO’s La Silla Observatory in Chile, shows two dramatic star formation regions in the southern Milky Way. The first is of these, on the left, is dominated by the star cluster NGC 3603, located 20 000 light-years away, in the Carina–Sagittarius spiral arm of the Milky Way galaxy. The second object, on the right, is a collection of glowing gas clouds known as NGC 3576 that lies only about half as far from Earth.