The Crab Nebula - Messier 1 in the Constellation Cancer

 

The Crab Nebula - HSO narrow band palette- Open University, telescope.org COAST robotic telescope. Credit Pip Stakkert Jodrell Plank Observatory

"In 1014 a large star ran out of  hydrogen gas to fuse at its core. Up until this point the outward pressure created by the nuclear fusion balanced the inward gravitational force. A catastrophic collapse occurred with a resultant explosion in a Type 11 supernova! The mass of the star at collapse was too great to have formed a 'white dwarf' star but insufficient to have created a black hole. At the centre of the Crab Nebula there is a rotating 'neutron star' called a 'Pulsar'. The above image is composed from light captured by the robotic camera-telescope combination using three separate filters, which relate to the wavelength of ionised elements - Hydrogen Alpha (656nm), Sulphur II (672nm) and Oxygen III (501nm). The image is therefore of some scientific value in identifying where these excited atoms are located within the supernova debris. In the  HSO palette; excited hydrogen atoms are shown red coloured, Sulphur shown green and Oxygen shown blue.

Hubble Space Telescope image of the centre of the Crab Nebula. the rightmost of the two bright stars at the centre of the image is the pulsar. Credit:NASA and ESA; Acknowledgment: J. Hester (ASU) and M. Weisskopf (NASA/MSFC

The Nebula is 6500 light years distant and sits within the Perseus arm of the Milky Way. It is not possible to see it with the naked eye but it is said that it may be seen with binoculars from a dark location. I however, have never been able to see it other than through a telescope eyepiece. The Crab Nebula is approximately 11 light years across and is expanding at a rate of 1,500 km per second. By comparison the pulsar at its centre has a diameter of at most 30 km. Messier 1 is a very bright source of Gamma Rays, X rays and Radio waves and the pulsar at its centre was the first to be discovered by Dr Susan Jocelyn Bell" - Kurt Thrust current Director of the Jodrell Plank Observatory..

Catching Crabs

MESSIER 1 the Crab Nebula - Credit Open University COAST Robotic Telescope - telescope.org and the Bradford Robotic Telescope. Combination of data from both telescopes taken several years apart and one using standard RGB filters and one using SHO filters - Credit Pip Stakkert Imaging Team Leader at the Jodrell Plank Observatory.

Crop from the above image: Credits:Open University COAST Robotic Telescope - telescope.org, the Bradford Robotic Telescope and  Pip Stakkert Imaging Team Leader at the Jodrell Plank Observatory.

"In 1054 AD, Chinese astronomers noted a bright star in the constellation Taurus the Bull, this was a supernova, a star that having fused its reserves of helium gas under went a cataclysmic gravitational collapse. The resulting mega-explosion created the supernova remnant the Crab Nebula - Messier 1 and a spinning Neutron Star known as a 'Pulsar'. The Crab Nebular is 6500 light Years distant and has an apparent diameter of 7 arc minutes as viewed from the earth. It is expanding at 930 miles per second. The pulsar spins at 30.2 times per second and has a diameter between 17 and 19 miles. The Crab Nebula is too small and dim to be seen with the naked eye but it is said to be visible with the aid of binoculars. I have tried to view it through 11x80mm binoculars from a number of dark locations but with no success.  I have seen it through a number of telescopes.  One of the most spectacular viewings I have enjoyed was through the eyepiece of  Olly Penrice's large reflector at Les Granges in the South of France". - Kurt Thrust -acting CEO and current Director of the Jodrell Plank Observatory.

Image showing the location of the Pulsar at the heart of the Crab Nebula Credit: Bradford Robotic Telescope and Pip Stakkert.

Credit: Wikipedia