May 31, 1996 in Nation/World

Dramatic Sequences Of Crab Nebula Reveal New Phenomena

The Baltimore Sun
 

A “movie” assembled from still photos of the Crab Nebula is astonishing Hubble Space Telescope astronomers with never-before-seen details of movement and change in one of the most-studied objects in the sky.

Even from 7,000 light years away, scientists said, the Hubble movie shows powerful jets and gusts of subatomic particles racing away from the nebula’s core, generating shimmering “sprites,” bright blobs and concentric ripples as they smash through the surrounding dust and gas.

The dramatic movie sequences were assembled from photographs taken by Hubble during the past year and were screened publicly for the first time Thursday at National Aeronautics and Space Administration headquarters in Washington.

The Crab Nebula, a glowing, billowing cloud of gas and dust in the summer constellation Taurus, was discovered by an English astronomer, John Bevis, in 1731. Astronomers have learned since then that the nebula is the still-expanding remnant of a star that exploded more than 900 years ago. Historians have linked it to a “guest” star recorded by Chinese astronomers when it appeared suddenly in the summer of 1054.

At the core of the nebula is a dense “neutron star” - the “cinder” of the original star, formed by the collapse of electrons and protons left after the explosion.

The neutron star spins 30 times each second. That produces a rapid flashing visible from Earth that earned such objects the name “pulsar.”

Astronomers said the star’s rapidly spinning magnetic field - billions of times more powerful than Earth’s - sweeps up nearby charged atomic particles and ejects them in two ways revealed in the movie for the first time: in an equatorial “wind” blowing at half the speed of light, and in two ferocious polar jets - one fired north, the other south.


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