Hubble views the Crab Nebula M1
- Older HST Crab Nebula M1 release
Hubble Captures Dynamics Of Crab Nebula
A new sequence of Hubble Space Telescope images of the remnant of a tremendous
stellar explosion is giving astronomers a remarkable look at the dynamic
relationship between the tiny Crab Pulsar and the vast nebula that it powers.
The colorful photo on the left shows a ground-based image of the entire Crab
Nebula, the remnant of a supernova explosion witnessed over 900 years ago.
The nebula, which is 10 light-years across, is located 7,000 light-years away
in the constellation Taurus. The green, yellow and red filaments concentrated
toward the edges of the nebula are remnants of the star that were ejected into
space by the explosion.
At the center of the Crab Nebula lies the Crab Pulsar — the collapsed core of
the exploded star. The Crab Pulsar is a rapidly rotating neutron star — an
object only about six miles across, but containing more mass than our Sun. As
it rotates at a rate of 30 times per second the Crab Pulsar’s powerful
magnetic field sweeps around, accelerating particles, and whipping them out
into the nebula at speeds close to that of light.
The blue glow in the inner part of the nebula — light emitted by energetic
electrons as they spiral through the Crab’s magnetic field — is powered by
the Crab Pulsar.
The picture on the right shows a Hubble Space Telescope image of the inner
parts of the Crab. The pulsar itself is visible as the left of the pair of
stars near the center of the frame. Surrounding the pulsar is a complex of
sharp knots and wisp-like features. This image is one of a sequence of Hubble
images taken over the course of several months. This sequence shows that the
inner part of the Crab Nebula is far more dynamic than previously understood.
The Crab literally “changes it stripes” every few days as these wisps stream
away from the pulsar at half the speed of light.
The Hubble Space Telescope photo was taken Nov. 5, 1995 by the Wide Field and
Planetary Camera 2 at a wavelength of around 550 nanometers, in the middle of
the visible part of the electromagnetic spectrum.
Credit: Jeff Hester and Paul Scowen (Arizona State University), and NASA
This image is also available as:
black & white hi-res jpeg [294k]
From this image, screen-sized versions are available
(e.g., for your computer screen background)
Changes In The Crab Pulsar
Scientists are learning more about how pulsars work by studying a series of
Hubble Space Telescope images of the heart of the Crab Nebula. The images,
taken over a period of several months, show that the Crab is a far more
dynamic object than previously understood.
At the center of the nebula lies the Crab Pulsar. The pulsar is a tiny object
by astronomical standards — only about six miles across — but has a mass
greater than that of the Sun and rotates at a rate of 30 times a second. As
the pulsar spins its intense magnetic field whips around, acting like a sling
shot, accelerating subatomic particles and sending them hurtling them into
space at close to the speed of light. The tiny pulsar and its wind are the
powerhouse for the entire Crab Nebula, which is 10 light-years across — a
feat comparable to an object the size of a hydrogen atom illuminating a volume
of space a kilometer across.
The three pictures shown here, taken from the series of Hubble images, show
dramatic changes in the appearance of the central regions of the nebula.
These include wisp-like structures that move outward away from the pulsar at
half the speed of light, as well as a mysterious “halo” which remains
stationary, but grows brighter then fainter over time. Also seen are the
effects of two polar jets that move out along the rotation axis of the pulsar.
The most dynamic feature seen — a small knot that “dances around” so much
that astronomers have been calling it a “sprite” — is actually a shock front
(where fast-moving material runs into slower-moving material)in one of these
polar jets.
The telescope captured the images with the Wide Field and Planetary Camera 2
using a filter that passes light of wavelength around 550 nanometers, near the
middle of the visible part of the spectrum. The Crab Nebula is located 7,000
light-years away in the constellation Taurus.
Credit: Jeff Hester and Paul Scowen (Arizona State University), and NASA
This image is also available as:
Illustration of the Crab Nebula Environment
Animation depicting the environment around the pulsar.
The sequence depicts the environment immediately around the central,
rotating pulsar. The twin beams demonstrate the rotation of the
neutron star which is surrounded by the equitorial wind (shaded red).
As the observer pulls away from the pulsar, first the
“inner knot” appears from the upper left, then followed by the
“sprite”, and finally, the jets which appear on opposing sides of the
pulsar.
Artist: Walt Feimer, STSci
The movie is constructed from eight WFPC2 images and contains four
sequences: 1) The full WFPC2 field, 2) a closer view of the pulsar, 3)
closer still detailing the “sprite” which appears towards the top, and
4) extreme closeup of the pulsar and the inner knot just above it.
Last Modification: 3 May 1998 15:00 MET