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Posts Tagged ‘magnetic’

NASA’s Fermi Satellite Finds Hints Of Starquakes In Magnetar ‘Storm’

October 24, 2014 Leave a comment

Image Credit: NASA's Goddard Space Flight Center/S. Wiessinger

Image Credit: NASA’s Goddard Space Flight Center/S. Wiessinger

NASA’s Fermi Gamma-ray Space Telescope detected a rapid-fire “storm” of high-energy blasts from a highly magnetized neutron star, also called a magnetar, on Jan. 22, 2009. Now astronomers analyzing this data have discovered underlying signals related to seismic waves rippling throughout the magnetar.

Such signals were first identified during the fadeout of rare giant flares produced by magnetars. Over the past 40 years, giant flares have been observed just three times — in 1979, 1998 and 2004 — and signals related to starquakes, which set the neutron stars ringing like a bell, were identified only in the two most recent events.

“Fermi’s Gamma-ray Burst Monitor (GBM) has captured the same evidence from smaller and much more frequent eruptions called bursts, opening up the potential for a wealth of new data to help us understand how neutron stars are put together,” said Anna Watts, an astrophysicist at the University of Amsterdam in the Netherlands and co-author of a new study about the burst storm. “It turns out that Fermi’s GBM is the perfect tool for this work.”

Link To Full Story And Video

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Magnetar Formation Mystery Solved?


 Artist’s impression of the magnetar in the star cluster Westerlund 1. Credit: ESO/L. Calçada


Artist’s impression of the magnetar in the star cluster Westerlund 1. Credit: ESO/L. Calçada

Magnetars are the bizarre super-dense remnants of supernova explosions. They are the strongest magnets known in the Universe — millions of times more powerful than the strongest magnets on Earth.

When a massive star collapses under its own gravity during a supernova explosion it forms either a neutron star or black hole. Magnetars are an unusual and very exotic form of neutron star. Like all of these strange objects they are tiny and extraordinarily dense — a teaspoon of neutron star material would have a mass of about a billion tonnes — but they also have extremely powerful magnetic fields. Magnetar surfaces release vast quantities of gamma rays when they undergo a sudden adjustment known as a starquake as a result of the huge stresses in their crusts.

The Westerlund 1 star cluster, located 16 000 light-years away in the southern constellation of Ara (the Altar), hosts one of the two dozen magnetars known in the Milky Way.

“In our earlier work (eso1034) we showed that the magnetar in the cluster Westerlund 1 (eso0510) must have been born in the explosive death of a star about 40 times as massive as the Sun. But this presents its own problem, since stars this massive are expected to collapse to form black holes after their deaths, not neutron stars. We did not understand how it could have become a magnetar,” says Simon Clark, lead author of the paper reporting these results.

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Scientists Detect Magmatic Water On Moon’s Surface

August 27, 2013 Leave a comment

Scientists have detected magmatic water — water that originates from deep within the Moon’s interior — on the surface of the Moon. These findings, published in the August 25 issue of Nature Geoscience, represent the first such remote detection of this type of lunar water, and were arrived at using data from NASA’s Moon Mineralogy Mapper.

“For many years, researchers believed that the rocks from the Moon were ‘bone dry’ and that any water detected in the Apollo samples had to be contamination from Earth,” said Klima, a member of the NASA Lunar Science Institute’s (NLSI) Scientific and Exploration Potential of the Lunar Poles team. “About five years ago, new laboratory techniques used to investigate lunar samples revealed that the interior of the Moon is not as dry as we previously thought. Around the same time, data from orbital spacecraft detected water on the lunar surface, which is thought to be a thin layer formed from solar wind hitting the lunar surface.”

Full Story: http://www.jhuapl.edu/newscenter/pressreleases/2013/130826.asp

New Method Detects Emerging Sunspots Inside the Sun

August 19, 2011 Leave a comment

New Method Detects Emerging Sunspots Inside the Sun

A full disk image of the Sun showing the sunspot group in AR11158 after emergence, observed by SDO/HMI. Courtesy of NASA/SDO and the HMI science teams.

The first clear detection of emerging sunspot regions prior to any indication of the region in magnetograms was published in Science on 19 August 2011.

Sunspots, dark features in the solar photosphere with strong magnetic field, have been observed for more than 400 years. They are the most visible components of regions where solar flares and coronal mass ejections (CMEs) occur, and these eruptive events may cause power outages and interruptions of telecommunication and navigation services on the Earth. Although it is widely believed that sunspot regions are generated in the deep solar interior, the detection of these regions before they emerge from the convection zone into the photosphere has remained undetected until now.

Full Story: http://hmi.stanford.edu/Press/18Aug2011/