2019 September 19
Explanation:
Delicate in appearance,
these filaments of shocked, glowing gas,
are draped across planet Earth's sky toward the constellation of Cygnus.
They form the western part of
the Veil
Nebula.
The Veil Nebula itself is a large
supernova remnant, an expanding
cloud born of the death explosion of a massive star.
Light from the original supernova explosion likely reached
Earth over 5,000 years ago.
Blasted out in the cataclysmic event, the interstellar shock wave
plows through space sweeping up and exciting interstellar material.
The glowing filaments are really more like long ripples in a sheet seen
almost edge on, remarkably well separated into
atomic hydrogen (red) and oxygen (blue-green) gas.
Also known as the Cygnus Loop, the
Veil Nebula now spans
nearly 3 degrees or about 6 times the diameter of
the full Moon.
While that translates to over 70 light-years
at its estimated distance of 1,500 light-years,
this telescopic image
of the western portion spans about
half that distance.
Brighter parts of the western Veil are
recognized as separate nebulae, including The
Witch's Broom
(NGC 6960) along the top of this view and
Pickering's Triangle (NGC 6979)
below and left.