Spiral Galaxy NGC 4517 in Virgo

This is a 7 minute exposure with an STL-1301E CCD camera thru Kopernik's 20-inch F/8.1 Ritchey Chretien Cassegrain telescope. The field of view is about 13x16 arc minutes, with North at the top.

Dreyer's description from the New General Catalog (NGC): "Considerably bright, very large, very moderately extended 89°, pretty bright star in contact."

NGC 4517 is an edge-on Spiral Galaxy in the Constellation of Virgo. It has a bright center, but no visible nucleus. It has a complex structure with many dark lanes. The galaxy forms a non-interacting pair with NGC 4517A, which lies just outside of the field of the Kopernik image above. A rough distance estimate for this galaxy (assuming a Hubble Constant of 73 km/sec per MegaParsec) is 50 million light years. At that distance the diameter of the galaxy would be 152,500 light years.

This galaxy was discovered by William Herschel in 1784. His son, John Herschel, recorded this object as a new discovery in 1828, with an error of 5 minutes in RA (west), and a description that makes it certain that he was observing this galaxy. This re-observation became NGC 4437, but it is identical to his father's earlier discovery which is NGC 4517. Thus this galaxy has two entries in the New General Catalog: NGC 4437, and NGC 4517.

• NGC 4517 (aka NGC 4437)
• Magnitude: 11.4
• Constellation: Virgo
• RA: 12h 32m 45.6s
• Dec: +00° 06' 59" Epoch 2000
• Size (mins): 10.4' x 1.5'
• Classification: SA(s)cd: sp
                           Spiral Galaxy, S shaped (uncertain), spindle shaped
  
  

George Normandin, KAS

May 8th, 2007