Neutron Star “Bites” Companion Star
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An artist's impression of XMM-Newton. Credits: ESA-C. Carreau
ESA’s XMM-Newton space observatory has observed a faint star flare up to almost 10,000 times it’s normal brightness in the X-ray portion of the electromagnetic spectrum. The outburst is speculated to be a result of the star attempting to “eat” a clump of matter expelled from its blue super-giant companion star. The source of the outburst is a neutron star about 10 km in diameter. Neutron stars are extremely dense “core” remnants of large stars. Given their small size and extreme density, neutron stars generate very strong gravitational fields.“This was a huge bullet of gas that the star shot out, and it hit the neutron star allowing us to see it,†said team leader Enrico Bozzo, ISDC Data Centre for Astrophysics, University of Geneva, Switzerland.
Lasting for about four hours, the flare and X-ray emissions came from the gas in the clump as it was heated to millions of degrees as it was pulled into the neutron star’s intense gravity field. Despite the neutron star’s immense gravity field, the clump of matter was so large only a small amount actually hit the neutron star and had the star not been in the way, the clump would have most likely disappeared into space. XMM-Newton detected the flare during a planned 12.5-hour observation of the system, only by catalog number IGR J18410-0535. Interestingly enough, the research team was not immediately aware of the discovery.
Artist's impression of a neutron star partially devouring a massive clump of matter. Image Credit: ESA/AOES Medialab
Nearly two weeks after the observations, Bozzo and his team received the data and realized XMM-Newton was not only pointed in the right direction for the observation of the flare, but their observations had also captured the entire duration of the flare, from beginning to end.“I don’t know if there is any way to measure luck, but we were extremely lucky,†said Bozzo, who estimates that flares of this magnitude can be expected a few times a year at most for the IGR J18410-0535 star system.
The research team was able to use the duration of the flare to estimate the size of the clump at about 16 million km across (about 100 billion times the volume of the Moon). Despite the incredible volume of the clump, using estimates made from the flare’s brightness, the clump was only about 1/1000th of our moon’s mass. The process of a star expelling matter into space is commonly referred to as “stellar wind” and in the case of this blue super-giant its stellar wind is expelled in a clumpy manner.
“This remarkable result highlights XMM-Newton’s unique capabilities,†adds Norbert Schartel, XMM-Newton Project Scientist. “Its observations indicate that these flares can be linked to the neutron star attempting to ingest a giant clump of matter.â€
Source: European Space Agency Press Release
Ray Sanders is a Sci-Fi geek, astronomer and blogger. Currently researching variable stars at Arizona State University, he writes for Universe Today, The Planetary Society blog, and his own blog, Dear Astronomer
2012-12-04 08:06:17
Source: http://www.dearastronomer.com/2011/06/28/neutron-star-bites-companion-star/
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