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The Tarantula Nebula, also known as 30 Doradus and NGC 2070, is a large region of ionized gas surrounding a collection of newly-forming stars at the eastern end of the stellar bar in the Large Magellanic Cloud (many similar regions are scattered through the LMC; see Kennicutt et al. 1995, Astronomical Journal, 109, 594). Hydrogen gas around the hot, young, massive stars is ionized by their ultraviolet radiation and glows as it recombines. The same process illuminates the Orion Nebula, even though it is only a hundredth the size of the Tarantula. Supernova 1987A, which was visible to the naked eye, appeared in this region. Stars which undergo such explosions live for only a few million years, and thus do not often travel far from their birthplaces.
The false-color image above is a log-scale display of a mosaic of several images taken with a CCD camera on the 0.6m Curtis Schmidt telescope at Cerro Tololo Inter-American Observatory in December 1994. I was on an observing run and had a few minutes during morning twilight to waste on pretty pictures. The images were taken with a Hydrogen-alpha filter in order to maximize sensitivity to the emission nebulosity. The red color, though artificial, should approximate the 6575 Å wavelength of the filter and of the H-alpha light from the nebula. The mosaic measures about 0.6 degrees across, which at the distance of the LMC translates to a bit over 1700 light years.
I also have a composite image below which adds blue colors from a broadband filter to the red from H-alpha. The area covered is not quite the same, so some blue information is missing from the bottom of the picture. But it shows a little more clearly where many of the massive stars are located. Unfortunately I did not have time to take a green Oxygen [III] image to fold into the mix in the same way as for M42, so this isn't exactly a ``true color'' representation. For a better example of that, see this ESO 2.2m telescope shot.
Funding for these CTIO observations was provided by NASA through the Wide-field Imaging Survey Polarimeter (WISP) project at the University of Wisconsin.