SOCO IMAGE GALLERY


 

M 40     

On the night of 24 October 1764, Charles Messier was searching for a "nebulous" object previously reported by the Polish astronomer (and brewer) Hevelius in the constellation Ursa Major. He found an object that he described as "Two stars, very near each other and very faint". He was not sure that this was the object that Hevelius had reported, particularly in light of the fact that he did not see any nebulosity associated with the two stars. Still, he included this pair of stars as number 40 in his list of "nebulous objects" (this is the pair of stars in the center of my image). This pair of stars is also known as Winnecke 4 after the German astronomer Friedrich August Theodor Winnecke, who in 1863 included it in his list of double stars. Winnecke was not aware that his object was the same as M 40. Today we know that the object that Hevelius was referring to is the star 74 Ursa Majoris, located about 1.3 degrees away from the position of M 40. 74 Ursa Majoris also does not shown any signs of nebulosity, so it is unknown why Hevelius described it as such.
As it turns out, Winnecke 4 is not even a true binary star system but simply a chance alignment of unrelated stars. The distances to the two components of Winnecke 4 are 1860 and 480 LY. The bright yellow-orange star to the upper right of M 40 is 70 Ursa Majoris, a magnitude 5.54 class K giant located at a distance of 640 LY.
There are a few interesting, though faint, objects around M 40. About halfway between M 40 and the top of my image is the faint barred spiral galaxy NGC 4290. It has a visual magnitude of 12.5 and is located around 125 million LY away. Fainter still is the small galaxy NGC 4284 located above it. Several other faint galaxies can be seen in the lower left corner of the image.

Date(s) Acquired: 12 February 2016
Telescope: Orion 120mm EON Apochromatic Refractor
Camera: QSI Model 583

 

   Exposure Time (min) 
   Number of Exposures
   RGB
   1.5
   
   -
   
   -
   OIII
   -
   RGB
   12
   
   0
   
   0
   OIII
   0

 

Processing:
Master red, green, and blue images created using SuperSIAM.
Color composite image created using Basic Processing Procedure III.
Color composite image contrast-stretched using Adobe Photoshop.




 

 

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