Anne’s Image of the Day: Spiral Galaxy NGC 7217
read more at Anne’s Astronomy News http://annesastronomynews.com/
August 21, 2013
NGC 7217, a spiral galaxy in Pegasus
Image Credit & Copyright: Adam Block/Mount Lemmon SkyCenter/University of Arizona (http://skycenter.arizona.edu/gallery/Galaxies/NGC7217)
NGC 7217 is an unbarred spiral galaxy that lies some 50 million light-years away from Earth in the northern constellation of Pegasus (the Winged Horse). It is receding from us at approximately 952 kilometers per second.
It is an active galaxy with an active galactic nucleus (a compact region at the center of a galaxy that has a much higher than normal luminosity, probably caused by accretion of mass by a supermassive black hole at the center of its host galaxy).
NGC 7217’s main features are the presence of three optical ring-like zones of stars concentric to its bright nucleus. It has a tight, flocculent spiral structure with two spiral arms in the region of the outer ring. This suggests that NGC 7217′s central regions have suffered several starbursts. The outer ring is dominated by bright blue stars and is the location of most of the recent star formation in the galaxy. Although the galaxy is very gas poor for a spiral, this ring is also where we find the hydrogen gas to be concentrated. The galaxy is surrounded by an extensive, nearly circular luminous halo.
Other features this galaxy has are the presence of a number of stars rotating in the opposite direction around the galaxy’s center to most of them and two distinct stellar populations: one of intermediate age on its innermost regions and a younger, metal-poor on its outermost ones. An additional noteworthy feature is a symmetric ring of dust that surrounds the nucleus. Other dust lanes are seen mainly on the near side of the galaxy.
It has been suggested these features were caused by a merger with another galaxy and, in fact, computer simulations show that NGC 7217 could have been a large lenticular galaxy that merged with one or two smaller gas-rich ones, becoming the spiral galaxy we see today. Anyway, right now this galaxy is isolated in space, with no nearby major companions.
This image is taken on August 3rd 2010 with a SBIG STL11000 CCD Camera on the 32-inch Schulman Telescope (RCOS) at Mount Lemmon SkyCenter.
n/a
Source: http://annesastronomynews.com/annes-image-of-the-day-spiral-galaxy-ngc-7217/
Anyone can join.
Anyone can contribute.
Anyone can become informed about their world.
"United We Stand" Click Here To Create Your Personal Citizen Journalist Account Today, Be Sure To Invite Your Friends.
Humic & Fulvic Liquid Trace Mineral Complex
HerbAnomic’s Humic and Fulvic Liquid Trace Mineral Complex is a revolutionary New Humic and Fulvic Acid Complex designed to support your body at the cellular level. Our product has been thoroughly tested by an ISO/IEC Certified Lab for toxins and Heavy metals as well as for trace mineral content. We KNOW we have NO lead, arsenic, mercury, aluminum etc. in our Formula. This Humic & Fulvic Liquid Trace Mineral complex has high trace levels of naturally occurring Humic and Fulvic Acids as well as high trace levels of Zinc, Iron, Magnesium, Molybdenum, Potassium and more. There is a wide range of up to 70 trace minerals which occur naturally in our Complex at varying levels. We Choose to list the 8 substances which occur in higher trace levels on our supplement panel. We don’t claim a high number of minerals as other Humic and Fulvic Supplements do and leave you to guess which elements you’ll be getting. Order Your Humic Fulvic for Your Family by Clicking on this Link , or the Banner Below.
Our Formula is an exceptional value compared to other Humic Fulvic Minerals because...
It’s OXYGENATED
It Always Tests at 9.5+ pH
Preservative and Chemical Free
Allergen Free
Comes From a Pure, Unpolluted, Organic Source
Is an Excellent Source for Trace Minerals
Is From Whole, Prehisoric Plant Based Origin Material With Ionic Minerals and Constituents
Highly Conductive/Full of Extra Electrons
Is a Full Spectrum Complex
Our Humic and Fulvic Liquid Trace Mineral Complex has Minerals, Amino Acids, Poly Electrolytes, Phytochemicals, Polyphenols, Bioflavonoids and Trace Vitamins included with the Humic and Fulvic Acid. Our Source material is high in these constituents, where other manufacturers use inferior materials.
Try Our Humic and Fulvic Liquid Trace Mineral Complex today. Order Yours Today by Following This Link.