M61 and NGC4303a


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By
Catalog
Obj Type
Location
Date Taken:
Gilbert
Messier 61
Galaxy
CTIO, Chile
05-09-2010
Description

Messier 61 (M61, NGC 4303) is a barred spiral galaxy in the southernmost part of the Virgo Cluster of Galaxies.

M61 was discovered by Barnabus Oriani on May 5, 1779 when following the comet of that year, 6 days before Charles Messier's discovery, who had seen it on the same day as Oriani but mistaken it for the comet. Messier mistook it for two nights more, until he realized that it did not move. As for a small number of others, this object was assigned an own number, H I.139, by William Herschel, who normally avoided to give own numbers to Messier's objects, when he observed and cataloged it on April 17, 1786.

M61 is one of the larger galaxies in the Virgo cluster; its 6 arc minutes of diameter correspond to about 100,000 light years, similar to the diameter of the Milky Way galaxy. Its 10th magnitude corresponds to an absolute magnitude of -21.2.

The small galaxy in the top right hand side of this image is NGC4303a.

This version has a 40% blend of a PixInsight processed version by Jack added.

Technical Details
Exposure Time:
LRGB (L 16x600 seconds, R 4x900s, G 7x900s, B 6x900s)
Camera:
Apogee U9
Telescope:
RCOS Carbon Truss 16 inch f/11.3 Ritchey-Chretien
Mount:
Software Bisque Paramount ME
© 2018 Gilbert
Used with permission, No reproduction of these images are permitted without written approval from Gilbert.