W5 is a nebula. A nebula is a collection of gas and dust existing between stars. /NASA, WISE, IRSA

The W5 emission nebula shines like a red heart. A nebula is a collection of gas and dust that exists between stars. An emission nebula emits light by receiving heat from its surroundings. A small open cluster is also included in the outer region of the nebula. A gathering of several young stars is called an open cluster. W5 is located about 6,500 light-years away in the direction of Cassiopeia (1 light-year is approximately 9.46 trillion kilometers).