THE NEBULOUS PLANETARY SH2-174
Image Credit & Copyright: T.A. Rector (University of Alaska Anchorage) and H. Schweiker (WIYN and NOAO/AURA/NSF). CLICK image for larger view and look below for related links and information.
As many of us know, planetary nebula are dying stars that shed their outer layers into the surrounding cosmos. That material is then illuminated by the exposed inner region of the soon to be white dwarf as it showers its former skin in massive doses of ultraviolet radiation. It may cross your mind that this doesn’t appear to be a classic telltale planetary nebula. They usually have a “look” to them where you can see defined lobes and shells with the dying star in or around the center. This one, not so much……
First things first; this photo was taken by the wide-field view of the mosaic camera on the Mayall 4-meter telescope on Kitt Peak. The colors here are primarily; red = Hydrogen-alpha, blue = Oxygen. Its shape is a product of its age as its old and the interstellar medium has morphed and shaped this planetary into what almost looks like a classical reflection nebula. The white dwarf, which is typically near the center, is the light blue star off to the right of the object, in the blue region.
NAME: Sharpless 2-174, Sh2-174, LBN 598.
WHAT IS IT?: Ancient planetary nebula.
HOW FAR AWAY IS IT?: Roughly 1000 light years.
HOW BIG IS IT?: Apparent dimensions on the night sky are about 10’x10’ arcminutes.
WHERE IS IT? (General): Constellation Cepheus.
WHERE IS IT? (Exact RA/DEC J2000): RA 23h 45m 02s / DEC +80° 57′ 00″.
National Optical Astronomy Observatory (NOAO) release of this image: http://www.noao.edu/news/2013/pr1301.php
NOAO image information: https://www.noao.edu/image_gallery/html/im1139.html
Travis Rector data page on this object: http://aftar.uaa.alaska.edu/gallery/details.cfm?img=334&type=