More Backyard Astronomy 2/20/2021. The Crab Nebula (catalogue designations M1, NGC 1952, Taurus A) is a supernova remnant and pulsar wind nebula in the constellation of Taurus. The supernova was documented by the Chinese in 1054 a.d. It was said that the supernova could be seen in broad daylight.

The nebula lies in the Perseus Arm of the Milky Way galaxy, at a distance of about 2.0 kiloparsecs (6,500 ly) from Earth. It has a diameter of 3.4 parsecs (11 ly), corresponding to an apparent diameter of some 7 arcminutes, and is expanding at a rate of about 1,500 kilometres per second (930 mi/s), or 0.5% of the speed of light.

At the center of the nebula lies the Crab Pulsar, a neutron star 28–30 kilometres (17–19 mi) across with a spin rate of 30.2 times per second, which emits pulses of radiation from gamma rays to radio waves. The Crab Nebula is generally the brightest persistent gamma-ray source in the sky. The nebula's radiation allows detailed study of celestial bodies that occult it. In the 1950s and 1960s, the Sun's corona was mapped from observations of the Crab Nebula's radio waves passing through it, and in 2003, the thickness of the atmosphere of Saturn's moon Titan was measured as it blocked out X-rays from the nebula.

I photographed this with my Meade LX200 ACF 14" Schmidt Cassegrain telescope using an ASI2600MC Pro one shot color camera and an Optolong Lenhance Ha and Ox3 filter. The photo is not enlarged as I used the telescope's full 3556 mm focal length unreduced at F10. It is comprised of 86 five minute exposures at a gain of 100 taken in three observing sessions. I autoguide with an off axis guider and a Starlight Express Lodestar II camera using the software PHD2. The photo was processed using Startools Version 1.7.457. In processing I attempted to bring out the shadow detail of the strings of gas resembling a plasma. Reminded me of spraying a can of string at an office party.

I am grateful for help from my wife Elizabeth, who puts up with me, for the color correction as I am badly colorblind. Thanks Liz. Hope you enjoy this version of the Crab Nebula.