Some of the most spectacularly beautiful nebulae come alive when viewed at non-optical wavelengths. This region is one of them. W40, as its called (also known as Sh2-64 or RCW 174), is a stellar nursery located some 1,000 light-years from Earth - in the constellation Aquila.
The nebula is comprised of several defining features. First and foremost, we have color filaments of interstellar dust clouds. Said filaments contain an upward of 600, young, vivacious stars (many are a part of Gould's belt - a series of stars that nearly circle our solar system entirely. Some of them lend light to famous constellations, such as Orion, Scorpius, and the Crux).
When peeking inside the stellar cocoon at infrared wavelengths, we can see the on-going activity within the dust. This brings us to our second feature: the stunning blue area that vaguely resembles a heart. This region contains at least three massive type-OB stars, which ionize the hydrogen gas, causing the illumination of the hydrogen cloud.