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NGC7000 - North America Nebula
The North America Nebula (NGC 7000 or Caldwell 20) is
an
emission nebula in the
constellation
Cygnus, close to
Deneb (the tail of the
swan and its brightest star).
The remarkable shape of the nebula resembles that of the continent of
North America, complete with a prominent
Gulf of Mexico. It is sometimes
incorrectly called the "North American Nebula".
The North America Nebula is large, covering an area of more than four times the
size of the full moon;
but its surface brightness is low, so normally it cannot be seen with the
unaided eye.
Binoculars and
telescopes with
large
fields of view (approximately 3°) will
show it as a foggy patch of light under sufficiently dark skies. However, using
a
UHC filter, which filters out some
unwanted
wavelengths of light, it can be seen by
the naked eye under dark skies. Its prominent shape and especially its reddish
color (from the
hydrogen Hα emission line)
show up only in photographs of the area.
Cygnus's Wall is a term for the "Mexico and Central America part" of the North
America Nebula. The Cygnus Wall exhibits the most concentrated
star formations in the nebula.
Between the Earth and the nebula complex lies a band of
interstellar dust that absorbs the light
of stars and nebulae behind it, and thereby determines the shape as we see it.
The distance of the nebula complex is not precisely known, nor is the star
responsible for ionizing the hydrogen so that it emits light. If the star
inducing the ionization is Deneb, as some
sources say, the nebula complex would be about 1800
light
years distant, and its absolute size (6° apparent diameter on the sky) would
be 100 light years.
Click on images for high resolution (opens new browser)
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My first try at NCG7000
Taken on 9/7/2008
Orion ED80
Hap Griffin Modified Canon 350D
51 90-second pictures
ISO 1600
Stacked with DeepSkyStacker
Processed with PhotoShop CS
Darks, Flat, Offsets applied
Copyright © 2008 – Antonio Pascarella |
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Same session as above. Over-processed to show North America outline. |
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