Skywatch

  • June 29, 2006

    Episode 43: Studying an Edge-On Galaxy

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    Astronomers like to see galaxies at various angles, since certain angles present better views of galaxies' structures. Recently, Hubble took a picture of NGC 5866, an "edge-on" galaxy. Our view of the galaxy is almost level with its edge. The galaxy was imaged in a variety of filters so that its tight, dark dust lane, flattened disk of blue stars and extended halo can be identified. Close examination of the image shows a small red bulge surrounding the nucleus of NGC 5866 and numerous globular clusters in an extended region around the halo. Had the galaxy been seen face-on, it would have revealed little more detail than a flat disk. NGC 5866 is a spectacular example of an "S0" galaxy. S0 galaxies have features of both smooth, uniform elliptical galaxies and complex spiral galaxies. They were originally thought to be transition objects between the two types of galaxies. Scientists now believe they may actually form in a variety of ways.