The Crab Nebula

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"The Crab Nebula" with Jane Houston Jones at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California.

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The Crab Nebula is one of the most intricately structured and highly dynamical objects ever observed. The new Hubble image of the Crab was assembled from 24 individual exposures taken with the NASA/ESA Hubble Space Telescope and is the highest resolution image of the entire Crab Nebula ever made.

• http://www.jpl.nasa.gov/missions/missionImages.cfm?missionType=WFPC&fullT...

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The Crab Nebula (catalogue designations M1, NGC 1952, Taurus A) is a supernova remnant and pulsar wind nebula in the constellation of Taurus.

The nebula was first observed by John Bevis in 1731, and corresponds to a bright supernova recorded by Chinese and Arab astronomers in 1054. At X-ray and gamma-ray energies above 30 KeV, the Crab is generally the strongest persistent source in the sky, with measured flux extending to above 1012 eV.

Located at a distance of about 6,500 light-years (2 kpc) from Earth, the nebula has a diameter of 11 ly (3.4 pc) and expands at a rate of about 1,500 kilometers per second.

At the center of the nebula lies the Crab Pulsar, a rotating neutron star, which emits pulses of radiation from gamma rays to radio waves with a spin rate of 30.2 times per second. The nebula was the first astronomical object identified with a historical supernova explosion.

The nebula acts as a source of radiation for studying celestial bodies that occult it. In the 1950s and 1960s, the Sun's corona was mapped from observations of the Crab's radio waves passing through it, and more recently, the thickness of the atmosphere of Saturn's moon Titan was measured as it blocked out X-rays from the nebula.

First observed in 1731 by John Bevis, the Crab Nebula corresponds to the bright SN 1054 supernova that was recorded by Chinese and Arab astronomers in 1054 CE. The nebula was independently rediscovered in 1758 by Charles Messier as he was observing a bright comet.

Messier catalogued it as the first entry in his catalogue of comet-like objects. The Earl of Rosse observed the nebula at Birr Castle in the 1840s, and referred to the object as the Crab Nebula because a drawing he made of it looked like a crab.

In the early 20th century, the analysis of early photographs of the nebula taken several years apart revealed that it was expanding. Tracing the expansion back revealed that the nebula must have become visible on Earth about 900 years ago. Historical records revealed that a new star bright enough to be seen in the daytime had been recorded in the same part of the sky by Chinese and Arab astronomers in 1054.

Given its great distance, the daytime "guest star" observed by the Chinese and Arabs could only have been a supernova—a massive, exploding star, having exhausted its supply of energy from nuclear fusion and collapsed in on itself.

Recent analysis of historical records have found that the supernova that created the Crab Nebula probably appeared in April or early May, rising to its maximum brightness of between apparent magnitude −7 and −4.5 (brighter than everything in the night sky except the Moon) by July.

The supernova was visible to the naked eye for about two years after its first observation. Thanks to the recorded observations of Far Eastern and Middle Eastern astronomers of 1054, Crab Nebula became the first astronomical object recognized as being connected to a supernova explosion.

• http://en.wikipedia.org/wiki/Crab_Nebula
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Category:

Science & Technology

Tags:

• crab
• nebula
• nasa
• jpl
• science
• astronomy
• astronomers
• m1
• ngc
• 1952
• taurus
• supernova
• explosion
• remnant
• esa
• eso
• hubble
• spitzer
• space
• telescopes
• pulsar
• neutron
• stars
• radiation
• messier
• comets
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• universe

[SireStefan]

I hope there's gonna be a supernova within my lifetime, I'd love to see that.

[toggsuk]

I looked up at the sky last night and even though there was no clouds at all, all I could see was about 20 stars. I guess you need to be far away from city lights.

[xXvolhvXx]

I am drunkl; I deid; found the Truth; Shiva; hate (chrsitianity; now is truth, Sciene; I am high; Satan. !! ♣

[sXeish]

@SireStefan It wouldn't have been within you lifetime because it would have already happened... its just the matter of if and when will the image get to us.

[SleepBoySleeps]

i live in dubai, and there are no clouds in this country considering that its a sandland.

and i always wished to see stars, never could i.

nature calls much?

[TheChipAndSkip]

@ajnode i have. :)

[ajnode]

@TheChipAndSkip

proves youre a city boy; go out into the country area and the night sky does not get destroyed by the glare of the city lights, you can still see a sky which is one of the most breathtaking sights

[johnnie160]

@TheChipAndSkip haha yeah. i have since bought myself a telescope and been out in the hills! brilliant!

[johnnie160]

@TheChipAndSkip haha yeah. i have since bought myself a telescope and been out in the hills! brilliant!