Crab Nebula

Another amazing image from the Hubble telescope. When you look at one of these, and compare it to what was obtainable from earth-based telescopes over the past 50 years, it seems almost unbelievably sharp and detailed. Yet earth-based telescopes can already surpass Hubble’s resolution, have for many years been able to surpass its light-gathering power. With the advent of multiple-mirror telescopes with adaptive optics, and long baseline optical interferometry, earth-based telescopes are on the verge of greatly exceeding the capabilities of any telescope that could reasonably be placed in space — with the possible exception of a lunar-based telescope, though how practical and reasonable that might be is certainly open for debate.

From the official Hubble web site:

This is a mosaic image, one of the largest ever taken by NASA’s Hubble Space Telescope of the Crab Nebula, a six-light-year-wide expanding remnant of a star’s supernova explosion. Japanese and Chinese astronomers recorded this violent event nearly 1,000 years ago in 1054, as did, almost certainly, Native Americans.

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. The neutron star, like a lighthouse, ejects twin beams of radiation that appear to pulse 30 times a second due to the neutron star’s rotation. A neutron star is the crushed ultra-dense core of the exploded star.

The Crab Nebula derived its name from its appearance in a drawing made by Irish astronomer Lord Rosse in 1844, using a 36-inch telescope. When viewed by Hubble, as well as by large ground-based telescopes such as the European Southern Observatory’s Very Large Telescope, the Crab Nebula takes on a more detailed appearance that yields clues into the spectacular demise of a star, 6,500 light-years away.

The newly composed image was assembled from 24 individual Wide Field and Planetary Camera 2 exposures taken in October 1999, January 2000, and December 2000. The colors in the image indicate the different elements that were expelled during the explosion. Blue in the filaments in the outer part of the nebula represents neutral oxygen, green is singly-ionized sulfur, and red indicates doubly-ionized oxygen.

Click on the thumbnail above for a nice large version of the photo mosaic…