[8] The North America Nebula covers a region more than ten times the area 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.
The dark cloud is however transparent to radio waves and infrared radiation, and these wavelengths reveal the central regions of Sh2-117 that are not visible to an ordinary telescope, including many highly luminous stars.
[10] The distances to the North America and Pelican nebulae were controversial, because there are few precise methods for determining how far away an HII region lies.
In 2004, European astronomers Fernando Comerón and Anna Pasquali searched for the ionizing star behind L935 at infrared wavelengths, using data from the 2MASS survey, and then made detailed observations of likely suspects with the 2.2 m telescope at the Calar Alto Observatory in Spain.