Astronomy Picture of the Day 9-12-02

NASA ^ | 9-12-02 | Robert Nemiroff and Jerry Bonnell

[petuniasevan]

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2002 September 12

X-Rays From Tycho's Supernova Remnant
Credit: SAO, CXC, NASA

Explanation: In 1572, Danish astronomer Tycho Brahe recorded the sudden appearance of a bright new star in the constellation Cassiopeia. The new star faded from view over a period of months and is believed to have been a supernova, one of the last stellar explosions seen in our Milky Way galaxy. Now known as Tycho's Supernova Remnant, the expanding debris cloud is shown in this detailed false-color x-ray image from the orbiting Chandra Observatory. Represented in blue, the highest energy x-rays come from shocked regions along the outer edges of the supernova remnant, corresponding to gas at temperatures of 20 million degrees Celsius. X-rays from cooler gas (only 10 million degrees or so!) dominate the remnant's interior. Unlike some other supernova remnants, no hot central point source can be found, supporting the theory that the origin of this stellar explosion was a runaway nuclear detonation that ultimately destroyed a white dwarf star. At a distance of about 7,500 light-years, Tycho's Supernova Remnant appears to be nearly 20 light-years across. This x-ray picture's field of view slightly cuts off the bottom of the generally spherical cloud.

[petuniasevan]

Astronomy Fun Fact:

Though technically a supernova, the Tycho event is kin to the novae which arise from a companion star's infalling stellar material accumulating on a white dwarf. "Little" events such as novae merely blow off the accumulated material in a titanic nuclear blast. But if the material accumulates until the dwarf star gains mass beyond the Chandrasekhar limit, watch out. Then it can destroy itself in the resulting explosion. Astronomers classify this as a Type Ia supernova, as opposed to the Type II (massive star at the end of its life explodes when out of fusion fuel).

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[petuniasevan]

[petuniasevan]

I don't usually use the APOD as a springboard for other endeavors, but this is the rare exception.

I wrote a 9/11 article and posted it this afternoon just before I left for work. Stuff was getting posted fast then, and I don't think a lot of people saw it. I'd like to take the opportunity to link it here. Thanks for having a look.

Appeasers, Apologists And The Legacy Of Terror

[sleavelessinseattle]

Hi P7! I did miss your post, thanks for the link, bookworm!
You Rock in History, TOO!

[sleavelessinseattle]

Here is an example of a type II Supernova, and some great specificity about the makeup of matter being ejected from the explosion in Cassiopeia

[petuniasevan]

Building Blocks for Planets^tm!

[2Trievers]

Is it Broca's Brain?
Amazing discoveries
Simply beautiful

&;-)

[BossyRoofer]

WOW! GOOD WORK APOD!

[TxBec]

Nicely written! Thank you..!