[1] It displays glowing ionized hydrogen gas and darker dust lanes.

[2] The brightest part of the nebula (a knot at its western edge) is separately classified as NGC 896, because it was the first part of the nebula to be discovered.

The nebula's intense red output and its morphology are driven by the radiation emanating from a small group of hot stars near the nebula's center.

[1] The Heart Nebula is also made up of ionised oxygen and sulfur gasses, which are responsible for the rich blue and orange colours seen in narrowband images.

The nebula also spans almost 2 degrees in the sky, covering an area four times that of the diameter of the full moon.