APOD: The Elusive Jellyfish Nebula (2010 May 15)

Comments and questions about the APOD on the main view screen.
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DavidLeodis
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Re: APOD: The Elusive Jellyfish Nebula (2010 May 15)

Post by DavidLeodis » Sun May 16, 2010 6:15 pm

Thanks 'bystander' for your help, which is appreciated. If you drink, have a :b: on me. :)

tesla
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Re: APOD: The Elusive Jellyfish Nebula (2010 May 15)

Post by tesla » Sun May 23, 2010 10:06 am

A neutron star is a mathematical assumption. It is not a known fact. It may fit our limited understanding at the moment, but that does not mean it exists.

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Chris Peterson
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Re: APOD: The Elusive Jellyfish Nebula (2010 May 15)

Post by Chris Peterson » Sun May 23, 2010 2:16 pm

tesla wrote:A neutron star is a mathematical assumption. It is not a known fact. It may fit our limited understanding at the moment, but that does not mean it exists.
A neutron star is a concept based on multiple lines of observational evidence, which combined make it almost certain to exist. That makes it far more than a "mathematical assumption".
Chris

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neufer
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The true source of the Geminids?

Post by neufer » Sun Dec 12, 2010 6:10 pm

http://www.universetoday.com/81623/wise-captures-an-infrared-shock-wave/ wrote:
WISE Captures an Infrared Shock Wave
by Nancy Atkinson on December 10, 2010
A JPL press release wrote: <<A circular rainbow appears like a halo around an exploded star in this new view of the IC 443 nebula from NASA’s Wide-field Infrared Survey Explorer, or WISE.

When massive stars die, they explode in tremendous blasts, called supernovae, which send out shock waves. The shock waves sweep up and heat surrounding gas and dust, creating supernova remnants like the one pictured here. The supernova in IC 443 happened somewhere between 5,000 and 10,000 years ago.

In this WISE image, infrared light has been color-coded to reveal what our eyes cannot see. The colors differ primarily because materials surrounding the supernova remnant vary in density. When the shock waves hit these materials, different gases were triggered to release a mix of infrared wavelengths.

The supernova remnant’s northeastern shell, seen here as the violet-colored semi-circle at top left, is composed of sheet-like filaments that are emitting light from iron, neon, silicon and oxygen gas atoms and dust particles heated by a fast shock wave traveling at about 100 kilometers per second, or 223,700 mph.

The smaller southern shell, seen in bright bluish colors, is constructed of clumps and knots primarily emitting light from hydrogen gas and dust heated by a slower shock wave traveling at about 30 kilometers per second, or 67,100 miles per hour. In the case of the southern shell, the shock wave is interacting with a nearby dense cloud. This cloud can be seen in the image as the greenish dust cutting across IC 443 from the northwest to southeast.

IC 443 lies near the star Eta Geminorum, which lies near Castor,
one of the twins in the constellation Gemini.>>

http://antwrp.gsfc.nasa.gov/apod/ap060602.html
http://antwrp.gsfc.nasa.gov/apod/ap030903.html
http://antwrp.gsfc.nasa.gov/apod/ap990721.html
http://antwrp.gsfc.nasa.gov/apod/ap970502.html
Art Neuendorffer

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bystander
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Re: The true source of the Geminids?

Post by bystander » Sun Dec 12, 2010 6:39 pm

Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor