The beautiful edge-on spiral galaxy NGC 891 in Andromeda. Note the complex structure of the dust in this disk, often considered an analog of the Milky Way. It's a somewhat challenging visual target unless the sky is very dark, demonstrating as in Centaurus A how much the visual detection of a galaxy suffers when the bright central regions are hidden by dust. The dust lane in NGC 891 shows delicate fine structure which suggests a turbulent mdium with lots of kinenetic energy imparted by such events as supernova explosions.
This image is in red light, taken deep in twilight with a Tektronix 2048x2048 CCD at the prime focus of the 4-meter Mayall telescope of Kitt Peak National Observatory. North is at the top and east to the left, for direct comparison with a chart or eyepiece view. The Sun rose only 40 minutes after the end of the exposure, giving a very bright sky background and causing the large number of saturated (and charge-trailing) star images. The field is 13.4 arcminutes on a side; the image shown here has been shrunk 4x for display, and if you click for the full image you'll get one 950 pixels tall that is half the size of the original.
Last changes: January 1999