Neutron star bites off more than it can chew

June 28, 2011, European Space Agency
Neutron star bites off more than it can chew
This animated sequence of images illustrates the partial ingestion of a clump of matter by the neutron star hosted in the Supergiant Fast X-Ray Transient, IGR J18410-0535. The ingestion of the clump material produced a dramatic increase in the X-rays released by the neutron star, which was detected with XMM-Newton. The peak in the X-ray luminosity corresponds to the period when the accretion rate was at its maximum. Credit: ESA/AOES Medialab

( -- ESA's XMM-Newton space observatory has watched a faint star flare up at X-ray wavelengths to almost 10 000 times its normal brightness. Astronomers believe the outburst was caused by the star trying to eat a giant clump of matter.

The flare took place on a neutron star, the collapsed heart of a once much larger star. Now about 10 km in diameter, the neutron star is so dense that it generates a strong .

The clump of matter was much larger than the neutron star and came from its enormous blue supergiant .

"This was a huge bullet of gas that the star shot out, and it hit the neutron star allowing us to see it," says Enrico Bozzo, ISDC Data Centre for Astrophysics, University of Geneva, Switzerland, and team leader of this research.

The flare lasted four hours and the came from the gas in the clump as it was heated to millions of degrees while being pulled into the neutron star's intense . In fact, the clump was so big that not much of it hit the neutron star. Yet, if the neutron star had not been in its path, this clump would probably have disappeared into space without trace.

caught the flare during a scheduled 12.5-hour observation of the system, which is known only by its catalogue number IGR J18410-0535, but the astronomers were unaware of their catch immediately.

The telescope works through a sequence of observations carefully planned to make the best use of the space observatory's time, then sends the data to Earth.

An artist's impression of XMM-Newton. Credits: ESA-C. Carreau

It was about ten days after the observation that Dr Bozzo and his colleagues received the data and quickly realised they had something special. Not only were they pointing in the right direction to see the flare, but the observation had lasted long enough for them to see it from beginning to end.

"I don't know if there is any way to measure luck, but we were extremely lucky," says Dr Bozzo. He estimates that an X-ray flare of this magnitude can be expected a few times a year at the most for this particular star system.

The duration of the flare allowed them to estimate the size of the clump. It was much larger than the star, probably 16 million km across, or about 100 billion times the volume of the Moon. Yet, according to the estimate made from the flare's brightness, the clump contained only one-thousandth of our natural satellite's mass.

These figures will help astronomers understand the behaviour of the blue supergiant and the way it emits matter into space. All stars expel atoms into space, creating a stellar wind. The X-ray flare shows that this particular blue supergiant does it in a clumpy fashion, and the estimated size and mass of the cloud allow constraints to be placed on the process.

"This remarkable result highlights XMM-Newton's unique capabilities," comments 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."

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not rated yet Jun 28, 2011
Poor thing has indigestion.
1 / 5 (10) Jun 28, 2011
Thanks for this story about recent observations of a neutron star.

Neutron stars are not dead nuclear embers of formerly vibrant stars, as once thought, but matter compacted to neutron density and highly-energized by repulsive interactions between neutrons:

1. "Attraction and repulsion of nucleons: Sources of stellar energy" Journal of Fusion Energy 19, 93-98 (2001).


2. "The Sun is a plasma diffuser that sorts atoms by mass", Physics of Atomic Nuclei 69, 1847-1856 (2006)

3. "Earth's Heat Source - The Sun", Energy and Environment 20, 131-144 (2009)

4. Is the Universe Expanding?" The Journal of Cosmology 13, 4187-4190 (2011)


With kind regards,
Oliver K. Manuel
4.5 / 5 (11) Jun 29, 2011
You really take the fun out of reading Physorg comments, Mr. Oliver K. Manuel. I am tired of you.
5 / 5 (2) Jun 29, 2011
This would seem to demonstrate that a solar-atmosphere cannot accumulate on a neutron star core beyond the amount that would would trigger a massive X-ray flare...
Game Over ??
1 / 5 (7) Jun 29, 2011
You really take the fun out of reading Physorg comments, Mr. Oliver K. Manuel. I am tired of you.

I regret that.

I also understand.

I too was restless and bored in my youth. I only wanted answers.

Research has been exhausting, boredat20, particularly when unexpected findings turned out to be unpalatable facts - difficult to accept.

But basic principles of science teach us to accept "what is" - whether or not we like it.

When I started research to try to rewrite the Biblical story of Genesis from a scientific perspective in 1960, I had no idea where that journey would led. Today I am grateful for the journey, although the conclusion is as surprising and distasteful to me as it is to you:

"The neutron-rich core of the Sun apparently gave birth to the Solar System, including all of the material that comprises us, and now bathes us with the sunlight, heat and energy that sustains us as intelligent, living creatures."

5 / 5 (1) Jun 30, 2011
Heh not only is omatumr a beliver in an neutron sun, and a beliver in the benifits his childcare methods have towards children and his sexuall satisfaction, but it seems he is a Bible humping weirdo too!
not rated yet Jun 30, 2011
wow... oma tumor is the father of scientology??

can you ask tom cruise to send me some money?

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