M100
Galaxy in the Constellation Coma Berenices

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Messier 100 (also known as NGC 4321) is a grand spiral galaxy located within the southern part of the constellation Coma Berenices.  It is one of the brightest galaxies in the Virgo Cluster, approximately 55 million light-years distant from Earth, and has a diameter of 160,000 light years.  It was discovered by Pierre Méchain on March 15, 1781 and was subsequently entered in Messier's catalogue of nebulae and star clusters after Charles Messier made observations of his own on April 13, 1781.  The galaxy was one of the first spirals discovered, and was listed as 1 of 14 spiral nebulae by Lord William Parsons of Rosse in 1850.  Above M 100 in the field of view are two conspicuous NGC galaxies and  the galaxy PGC 40214 at top-center.  NGC 4328 is located to the upper left of M100, and NGC 4323 is to the upper right of M 100.  NGC 4323 is a satellite galaxy of M 100 and is gravitationally bound to it.

Image Information  Courtesy of  SEDS and NASA

Image Details:

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  • Instrument:  Planewave Instruments CDK 12.5 Astrograph w/Astro-Physics AP27TVPH focal reducer @ f/6.3 (2000mm)
  • Mount:  AP1200GTOCP3
  • Image Scale:  1.22 arc-seconds per pixel after processing
    Camera: SBIG ST-2000XM with AO8 Adaptive Optics and CFW10 Color Filter Wheel using Custom Scientific LRGB filters 
    Filters & Exposure Times:
    • L:  20 x 5 minutes binned 1 x 1
    • R:  20 x 5 minutes binned 2 x 2
      G:    9 x 5 minutes binned 2 x 2
      B:  18 x 5 minutes binned 2 x 2
    • Multiple Luminance Layering in Photoshop (technique as described by Rob Gendler)
    • Total equivalent unbinned exposure time of 9.5 hours
    Software: Maxim DL/CCD, CCDStack, Adobe Photoshop CS2, RC Astro Gradient X-Terminator
    Location:  C.A.A.S. East Observatory, Little Rock, AR., El. 650ft
    Date: May 30th, 2011

Wade Van Arsdale
Little Rock, AR., USA
June 16th, 2011