Crab Nebula

 Crab Nebula

The Crab Nebula is an expanding remnant of a star's supernova explosion. Japanese and Chinese astronomers recorded this violent event nearly 1,000 years ago in 1054 AD, as did likely the Native Americans. The glowing relic has been expanding since the star exploded, and it is now approximately 11 light-years in width.

This Hubble mosaic is one of the largest images ever taken of a supernova remnant by the space telescope. It is also the highest resolution image ever made of the entire Crab Nebula, which is located 6,500 light-years away. The composite was assembled from 24 individual exposures taken with Hubble's Wide Field Planetary Camera 2 in October 1999, January 2000, and December 2000.

The orange filaments are the tattered remains of the star and consist mostly of hydrogen. The rapidly spinning neutron star embedded in the center of the nebula is the dynamo powering the nebula's eerie interior bluish glow. The blue light comes from electrons whirling at nearly the speed of light around magnetic field lines from the neutron star, which is the crushed, ultra-dense core of the exploded star.

Like a lighthouse, the neutron star produces twin beams of radiation. From Earth, it appears to pulse 30 times a second due to the neutron star's rotation sweeping the beams across our line of sight. It has the mass equivalent to the Sun crammed into a rapidly spinning ball of neutrons 12 miles across.

The nebula derived its name from its appearance in an 1844 drawing made by Irish astronomer Lord Rosse, who used a 36-inch telescope. When viewed by Hubble, as well as by large, ground-based telescopes, the Crab Nebula takes on a more detailed appearance that yields clues into the spectacular demise of the star.

In 2002, Emily Schaller and Robert Fesen of Dartmouth College used Hubble to examine the motion and shape of bright knots in the Crab Nebula. They found that the knots lie relatively close to the source of the ionizing radiation, which may lead to higher gas temperatures of the knots than expected. This limits our understanding of the structure of the nebula and what role magnetic fields may play as the material expands outward and eventually combines with other material to form new stars.

In 2010 and 2013, Allison Loll of Arizona State University used Hubble to determine several northwest-southeast (upper right to lower left) asymmetries in the nebula's filaments, as well as the development of long "fingers" of gas and dust. She attributes these to the sideways motion of the neutron star in the northwest (upper right) direction. Jeff Hester, also at Arizona State University, studied Hubble observations of the Crab Nebula along with data from other observatories to investigate the expansion and magnetic fields of the nebula remnant from the explosion.

Constellation: Taurus

Distance: 6,500 light-years (2.0 kiloparsecs)

Instrument: Wide Field Planetary Camera 2

Image Filters: F502N ([O III]), F631N ([O I]), F673N ([S II])

About The Object
Object Name Crab Nebula, NGC 1952
About The Object
Object Name A name or catalog number that astronomers use to identify an astronomical object.
Object Description The type of astronomical object.
R.A. Position Right ascension – analogous to longitude – is one component of an object's position.
Dec. Position Declination – analogous to latitude – is one component of an object's position.
Constellation One of 88 recognized regions of the celestial sphere in which the object appears.
Distance The physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs.
Dimensions The physical size of the object or the apparent angle it subtends on the sky.
About The Data
Data Description
  • Proposal: A description of the observations, their scientific justification, and the links to the data available in the science archive.
  • Science Team: The astronomers who planned the observations and analyzed the data. "PI" refers to the Principal Investigator.
Instrument The science instrument used to produce the data.
Exposure Dates The date(s) that the telescope made its observations and the total exposure time.
Filters The camera filters that were used in the science observations.
About The Image
Image Credit The primary individuals and institutions responsible for the content.
Publication Date The date and time the release content became public.
Color Info A brief description of the methods used to convert telescope data into the color image being presented.
Orientation The rotation of the image on the sky with respect to the north pole of the celestial sphere.