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Double Galaxies in the Constellation Pegasus
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This pair of galaxies is in the constellation Pegasus. A dynamically isolated binary system (number 570 in the catalog of double galaxies compiled by Igor Karachentsev), NGC 7332 and 7339 are too far apart for obvious interaction (such as tails and streamers), although they are almost certainly orbiting around each other. NGC 7332 is the brighter galaxy to the right (west) of the image. It shows evidence of partial dust lanes, has an extended envelope and possesses a compressed, bright, box-like central bulge. It is classified S0(pec), being an intermediate lenticular galaxy, and its peculiar tag refers to the unusual box-like shape of the central region (sometimes called peanut-shaped).
The accompanying NGC 7339 is seen edge-on and is thought to be of type Sbc (a mixed spiral), but its orientation makes it hard to classify exactly. It is also somewhat dimmer than its companion, although at a distance of about sixty million light years, neither is visible to the naked eye.
Receding from us at over eight hundred miles per second, they are orbiting each other at about sixty miles per second. This isn't as fast as it sounds for galaxies which are about a million trillion miles across.
Text Credit: Doug Williams, N.A.Sharp/AURA/NOAO/NSF and Earth And Sky
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