It's X-1 source was the first black hole to be discovered.
This constellation is ideal for studying star formation in OB associations because its OB2 object is the closest to us to house thousands of O and Btype stars. The nearly 3-degree wide Veil Nebula is part of this constellation's namesake Loop. Friedrich Bessel became the first to obtain an accurate stellar parallax, by using its "61" star. An elliptical galaxy emitting two radio jets, fueling two huge lobes, was the first radio galaxy to be discovered and is this constellation's A object. It is where the first Earth-sized planet in a star's habitable zone was found, and its brightest star is Deneb. It's X-1 source was the first black hole to be discovered. For 10 points, name this constellation that takes its name from the Latin for swan.
This constellation is ideal for studying star formation in OB associations because its OB2 object is the closest to us to house thousands of O and Btype stars.
Cygnus