M40 = Winnecke 4 ( 12h 22.4m +58°05´, 8.0 mag. )
This double star was included by Messier in his catalogue for unknown reasons - he observed it on October 24, 1764. Nebula was listed at this location by Hevelius in 1660. Its components, separated by 49 arcseconds, are magnitude 9.0 and 9.6 - their spectral types are G0 and F8 so they apear yellowish-white and bluish-white in the color CCD image above. M40 is visible in binoculars 17' NE of 70 Ursae Majoris or 1°25' NE of d Ursae Majoris (see finder chart below).
The above image was taken on May 9, 1999 from Sooke, BC. Cookbook 245 LDC CCD camera was used on Celestron Ultima 8 f6.3 telescope. Eight unguided white exposures (30 sec. each) were combined with cyan, magenta and yellow-filtered integrations (4 x 30 sec. each) using AIP4WIN. Color image was then adjusted in Lab color space with Corel PhotoPaint 8.
North is to the right.
Map created in Guide 7.0 - 7°45' x 7°45'. North is up.
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© Jan Wisniewski