The Crab Nebula is a supernova remnant in the constellation Taurus. It is also identified as M1, as it occupies the first position in the catalog of astronomical objects published by Messier in 1774.
Its apparent diameter is 6'x4': for comparison the full moon has a diameter of 30'.
The nebula, now more than six light-years wide, is formed by the expanding gas expelled during a supernova explosion; the expansion speed is 1500 km/s.
The supernova that produced it was observed for the first time on July 4, 1054 and was recorded by Chinese and Arab astronomers of the time; it was so bright that it was visible to the naked eye during the day, surpassing the apparent brightness of Venus. The Crab Nebula is located about 6500 years from the solar system; therefore the event that produced it actually occurred 6 500 years before 1054, i.e. around 5400 BC.
At the center of the nebula is the Crab pulsar, a neutron star with a diameter of about 28-30 kilometers, discovered in 1968: as the name suggests, this star emits its pulsations every 33 ms at all wavelengths of the electromagnetic spectrum, from radio waves to X-rays.
Optic GSO RC12 Truss - Aperture 304mm, focal lenght 2432mm, f/8
Mount 10Micron GM2000 HPSII
Camera ZWO ASI 2600 MM Pro with filter wheel 7 positions
Filters Astrodon Gen2 E-Serie Tru-Balance 50mm unmounted LRGB
Guiding system ZWO OAG-L with guide camera ASI 174MM
Exposure details L 31x300" bin3 -15C
R 18x300" bin3 -25C
G 17x300" bin3 -25C
B 18x300" bin3 -25C
Total integration 7h
Acquisition Voyager, PHD2
Processing Pixinsight 1.8, Photoshop CS5, StarXTerminator, NoiseXTerminator, BlurXTerminator
Location Promiod (Aosta Valley, Italy), own remote observatory
Date 25 January / 28 October 2022