| M1, NGC1952 The Crab Nebula Constellation: Taurus, Distance: 6,500 light years, Visual Magnitude: 8.4, Diameter: 8 x 8 arc mins Best viewed at 8:00pm Jan-Apr 10:00pm Dec-Mar, Max altitude 36 degrees North |
 |
The Crab Nebula is the remnants of the bright supernova that was recorded by Chinese and Arab astronomers in 1054 AD. The Crab Nebula itself was first observed in 1731 by John Bevis. The nebula was independently rediscovered in 1758 by Charles Messier and he catalogued it as the first entry in his catalogue of comet-like objects, the Messier objects. The Earl of Rosse observed the nebula at Birr Castle in the 1840s, and referred to the object as the Crab Nebula because a drawing he made of it looked like a crab. Given its great distance, the daytime "guest star" observed by the Chinese and Arabs in 1054 could only have been a supernova—a massive exploding star, having exhausted its supply of energy from nuclear fusion and collapsed in on itself. Recent analysis of historical records have found that the supernova that created the Crab Nebula probably rose to a maximum brightness of between apparent magnitude -7 and -4.5 (brighter than everything in the night sky except the Moon) by July in 1054. The supernova was visible to the naked eye for about two years after its first observation. |
| - imaged on 20110121 - 10" F/4.7 Newtonian Reflector - 500 video frames H-Aplha, 200 each of RGB (without IR/UV blocking filter-forgot it!) at x128 integration - bahtinov focusing mask, moonlight focuser - good polar alignment, full moon, excellent seeing, elevation about 35 degrees - processed in Registax, Photoshop, Astra Image Notes: colour balance off - need RGB with IR/UV block filter |