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> Polarisation structure of the Crab nebula (M1)

Polarisation structure of the Crab nebula (M1)

author: Caltech/Pasachoff/David Malin Images/Novapix

reference: a-snv11-00527

Image Size 300 DPI: 28 * 22 cm

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.

Keywords for this photo:

ASTRONOMY - EVOLUTION - M1 - MAGNETIC FIELD - NEUTRON STAR - NGC 1952 - PALOMAR - POLARISATION - PULSAR - STAR - SUPERNOVA - SUPERNOVA REMNANT - TAURUS -