The Cosmic Spider

NGC2070, the Tarantula Nebula, is a vast cloud of dust and gas situated in the Large Magellanic Cloud, approx' 163Kly (49.9Kpc) in distance from Earth. The Tarantula is so large that even from its great distance it is relatively easy to see it with the unaided eye, from a dark site. Some 1800ly across, if placed at the same distance as M42, the Orion Nebula, it would cover 1-3 of the entire sky and shine brighter than the 1st Quarter Moon, casting very noticeable shadows on the ground.

The nebula lies at the leading edge of the galaxy where star formation is now occurring at its highest rate. This is due to ram pressure created by the movement of the LMC through its local ISM (interstellar medium), which piles up the dust and gas in the galaxy via a shock front, creating a massive burst of star formation. Consequently, the amount of star formation has been considerable. The central cluster of the Tarantula Nebula (which is actually ngc2070, the nebula itself is technically 30Doradus), consists of hundreds of thousands of stars and weighs in at 450000 solar masses. It will probably eventually form a globular cluster, due to its extremely large size. At the very centre of the nebula lies the cluster R136, which is notable for its concentration of extremely large and bright stars. The largest of which is the star R136a1, a star that weighs in at around 315 solar masses and shines with the light of 8.7million Suns. So bright, it provides some 7% of the entire nebula's ionising radiation. A young star, at around a million years in age, despite its size and spectral classification (WN5h), it is still a Main Sequence star, burning hydrogen in its core. With a surface temp of around 53000K, it is also one of the hottest stars around. Though for all its other superlatives, the star itself is only around 30 times the size of our Sun. Being so massive, the star will burn through its core hydrogen supplies very quickly, and will most likely explode as an extremely luminous supernova within the next few million years.

Several other large nebula complexes can be seen surrounding the Tarantula and these are also areas of high star formation. Many supernova remnants are also visible in this image, appearing as large shells of gas expanding into the ISM. Nearby to these and the Tarantula itself is the site for the brightest supernova seen in several hundred years, SN1987a. Still being intensely studied after more than 30 years, SN1987a is still a challenging object where theories of the end of star's lives is concerned.

Pic was taken with t68 at the Bathurst Observatory (BAT-iTelescope Network), 10x120sec subs.
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