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Original
Diffraction spikes
50% crop
100% crop
The Crab Nebula (catalogue
designations M1,
NGC 1952,
Taurus A) is a supernova remnant and pulsar wind
nebula in the constellation of Taurus. The nebula was
observed by John Bevis in 1731; it corresponds to a bright
supernova recorded by Chinese and Arab astronomers in 1054.
At X-ray and gamma-ray energies above 30 KeV, the Crab is
generally the strongest persistent source in the sky, with
measured flux extending to above 1012 eV. Located at a
distance of about 6,500 light-years (2 kpc) from Earth, the
nebula has a diameter of 11 ly (3.4 pc) and expands at a
rate of about 1,500 kilometres per second.
At the
centre of the nebula lies the Crab Pulsar, a neutron star
(or spinning ball of neutrons), 28-30km across,[5] which
emits pulses of radiation from gamma rays to radio waves
with a spin rate of 30.2 times per second. The nebula was
the first astronomical object identified with a historical
supernova explosion.
The
nebula acts as a source of radiation for studying celestial
bodies that occult it. In the 1950s and 1960s, the Sun's
corona was mapped from observations of the Crab'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.
The
cloudy remnants of SN 1054 are now known as the Crab Nebula.
The nebula is also referred to as Messier 1 or M1, being the
first Messier Object catalogued in 1758.
The
above text is taken from
Wikipedia.
Considering the short integration time (2hrs and 45min at
f6.3) I was a surprised at how much signal that was
captured. I guess it is the brightness of the Nebula that
one should thank for that. The fall of 2010 has seen very
few nights with clear skies, but this one was exceptionally
good - which also helped.
By
"mouse over" on the blue text just below the image you can
see:
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Original: the main processed image and the image that is
displayed when you load this web page.
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Diffraction spikes: I could not help it, but I
played a little with Carboni's PS tools to create some
diffraction spikes. Just for fun :-)
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50% crop: A 50% crop of the original image
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100% crop: A 100% crop of the original image
The
following software has been used. MaximDL (image
acquisition and guiding), CCDStack (calibration and de-convolution),
PixInsight (cropping, background correction, colour
corrections) and Photoshop CS5 (all the rest, incl Noel
Carbonis Astronomy Tools).
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