Last updated on April 18, 2014 at 17:24 EDT
Edge-On Galaxy ESO 342-G017
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Edge-On Galaxy ESO 342-G017

April 27, 2005
The galaxy ESO342-G017 was observed on August 19, 1998 during a spell of excellent observing conditions. Two exposures, each lasting 120 seconds, were taken through a red filtre to produce this photo. The quality of the original images is excellent, with seeing (FWHM) of only 0.26 arcsec measured on the stars in the frame.

ESO342-G017 is an Sc-type spiral galaxy seen edge-on, and the Test Camera was rotated so that the disk of the galaxy appears horizontal in the figure. Thanks to the image quality, the photo shows much detail in the rather flat disk, including a very thin, obscuring dust band and some brighter knots, most probably star-forming regions.

This galaxy is located well outside the Milky Way band in the southern constellation of Sagittarius. Its distance is about 400 million light-years (recession velocity about 7,700 km/sec). A number of more distant galaxies are seen in the background on this short exposure.