M1: Crab Nebula, Taurus
Very small for something so famous...the first item in Messier's catalogue.
But significant nonetheless, a remnant of a star that exploded as a Type 2 supernova in 1054 AD. It was recorded as bright enough to see in daytime for days afterwards by Japanese and Chinese astronomers. The delicate filaments are the remains of the star's atmosphere, blasted away when a giant star (9 times as massive as our sun) explodes.
What's left at the core is a rapidly spinning neutron star (a pulsar), whose radiation energises the expanding gas cloud. The Crab Pulsar is only about 28-30km across, and spins 30.2 times every second.
The nebula is now about 11 light years across, expanding at about 1,500 kilometres per second (which sounds fast but its only 1/200th of the speed of light).
Orion Optics UK AG16 Astrograph: SBIG 11000 CM single shot colour camera, CCDStack, PhotoshopCS5, Pixinsight: Losmandy Titan Mount
15 x 10 mins IDAS1 filter (2hrs 30 mins total)
Data capture February 2015