M1 = NGC1952 ( 5h 34.5m +22°01´, 8.4 mag )
Crab Nebula is a remnant of a supernova which exploded in Taurus on July 4, 1054. Noted in Chinese chronicles, "guest" star was a daylight object for 23 days then, gradually decreasing in brightness, it ceased to be visible to the unaided eye in the spring of 1056. Nebula generated in that explosion was discovered by John Bevis in 1731. Messier decided to start his catalogue of "nebulous" objects (which he hoped would prevent confusion during searches for new comets) after finding M1 when following bright comet on September 12, 1758. The common name of M1 was coined by Lord Rosse, who noticed nebula's bright filaments while observing it in 36" speculum reflector in 1844. Crab Nebula is about 6,500 ly away and at its center contains 16th magnitude neutron star spinning 30x per second - that pulsar's strong magnetic field excites surrounding gas to glow. M1 can be spotted in a telescope just 1°10' NW of z Tauri (see finder chart below).
The above image was taken on September 26, 1998 from Sooke, BC (color) and February 13, 2002 from Harrowsmith, Ontario (luminosity). Cookbook 245 LDC CCD camera was used on Celestron Ultima 8 f6.3 telescope autoguided with Cookbook 211 LDC CCD camera on piggybacked 500mm f8 telephoto lens. Nine white exposures (240 sec. each) as well as cyan, magenta and yellow-filtered integrations (6 x 240 sec. each) were processed with AIP4WIN software. Color image was then adjusted in Lab color space using Corel PhotoPaint8.
North is down.
Map created in Guide 7.0 - 7°45' x 7°45'. North is up.
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© Jan Wisniewski