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North America Nebula

C20, NGC 7000

Proper NameNorth America Nebula
Caldwell NumberC20
NGC/IC NumberNGC 7000
Right Ascension20h 58m 47s
Declination+44° 19' 48"
Distancec.2,600 light years
c.800 parsecs
MagnitudeApparent: +4.0
Absolute: -5.5
Mean DiameterApparent: 120° x 100°
Actual: 90 light years
Optimum VisibilityAugust
NotesPart of a wide cloud of hydrogen spreading through the sky eastward of Deneb, the North America Nebula is part of the same region as the Pelican Nebula (IC 5067 and IC 5070), though a dense band of interposed dark material causes them to appear as separate nebulae as seen from Earth.

A wide expanse of gas and dust spanning some fifty light years, this bright nebula ia partially hidden behind dark trails of material. One dense strand divides it from the nearby Pelican Nebula (which is actually part of the same stucture) and etches the edge of the North America Nebula to give it a remarkable resemblance to the coastline of North America on Earth.

The similarity of form is clear between the North America Nebula and the continent from which it takes its name, at least on its western side. Beyond the dark region to the west (or right) is a second prominent nebula, the Pelican Nebula, which is actually an extension of the same nebulous cloud. Imagery provided by Aladin sky atlas

The North America Nebula covers an area of Earth's sky several times that of the Moon's disc, though at a distance of some 2,600 light years it is so faint that it is barely visible to the naked eye under even ideal conditions. It lies southward and eastward of the bright star Deneb at the tail of Cygnus the Swan, in the middle of the Milky Way and on the fringes of the dark cloud known as the Cygnus Rift.

The glow of the nebula's hydrogen clouds comes from the ionising effect of the young stars within it, notably the intensely hot O-type star HR 8023, which lies in approximately the region of the Great Lakes on the equivalent North American continent. This ionisation effect pushes outwards to form a boundary to the nebula, and this ionisation front is particularly noticeable along the nebula's southeastern side (or the western coast of Mexio on an analogous map of North America). There it forms a long sinuous structure known as the Cygnus Wall.


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