AAO image reference 'Crab polarisation'. « Previous || Next »
Top left is NE. Image width is about 9 arc min
Image and text © 1990-2002, Malin/Pasachoff/Caltech, Photograph from Hale 5m plates by David Malin.
The image was made from four plates taken on the Palomar (Hale) 5m telescope using a filter that excluded the emission lines, allowing only the highly polarised synchrotron light through. Each of the four images was taken with a Polariod filter rotated 45 degrees (ie 0 deg, 45, 90, 135, 180). One of these plates was contact copied to make a positive film copy, and this positive aligned in turn with each of the three remaining images, revealing the difference between them. These three difference images were used as the red, green and blue channels to make a colour negative which made the print. All the work was done photographically, but the image has subsequently been digitally remastered from the photographic derivatives. These colours would not be visible through a telescope, even with Polariod, since they are representative of something that cannot be seen, the inflated magnetic field of a star that exploded almost 1000 years ago.
Entry from NGC 2000.0 (R.W. Sinnott, Ed.) © Sky Publishing Corporation, 1988:
NGC 1952 Nb 05 34.5 +22 01 s Tau 68.4 vB, vL, E 135deg +/- , vglbM, r; = M1Related images
Crab nebula. The Crab nebula, M1 the Crab nebula.
Crab_wf. The Crab nebula, wide field view