Posted on 09/27/2011 5:52:32 PM PDT by SunkenCiv
An international team led by KU Leuven astronomer Leen Decin discovered not less than a dozen cold dust arcs around the giant star CW Leo. The team used the sensitive PACS instrument on board the Herschel Space Observatory to detect for the first time arcs of dust far away from the star. CW Leo has expelled these shells of dust in different epochs in its life. The faintest shell we can see now was, according to the team, expelled about 16,000 years ago. In the mean time it has drifted away from the star over more than 7,000 billion kilometers...
The different shells were ejected by the star with intervals of 500 to 1,700 years. The astronomers in the team believe such shells, even fainter, are also present further out, up to the violent bow shock where the expelled material of the star collides with the interstellar medium. The oldest shells have probably disappeared in the bow shock already...
Since the different shells have been travelling far away from the star by now, they are also very cold, about -248°C. The PACS instrument onboard the Herschel Space Telescope was especially designed to make images of the far-infrared light emitted by dust that cold...
Making the rings visible in the Herschel images was not trivial...
(Excerpt) Read more at sciencedaily.com ...
The images show the far-infrared light emitted by the cold dust particles in the arcs. Analysis of the images allows the astronomers to deduce the temperature and the amount of dust in each shell. Every shell is the witness of a different epoch in the mass loss history of the star. (Credit: Image courtesy of Katholieke Universiteit Leuven)
The Cycle of Cosmic Catastrophes:
Flood, Fire, and Famine
in the History of Civilization
by Richard Firestone,
Allen West, and
Simon Warwick-Smith
Another “extra extra” ping.
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The vacuum cleaner bag probably broke.
Aaarrrrgh! Universe pollution! Alert the EPA!!
Pull my nebula.
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