* Constellations are patterns: Constellations are patterns of stars as seen from Earth. They are not physical groupings of stars.
* Stars at different distances: The stars that make up a constellation are at vastly different distances from us.
* Brightness and visibility: The number of stars we can see in a constellation depends on our light pollution and the sensitivity of our eyes.
* Star charts: Star charts often show the brightest and most prominent stars in a constellation, but there are many fainter stars that are not included.
So, while we can identify key stars that form the shape of Cygnus, there are actually many, many stars within its boundaries.
