The Heart Nebula (also known as the Running dog nebula, IC 1805, Sharpless 2-190) is an emission nebula, 7500 light years away from Earth and located in the Perseus Arm of the Galaxy in the constellation Cassiopeia. It was discovered by William Herschel on 3 November 1787. It displays glowing ionized hydrogen gas and darker dust lanes.

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 stars near the nebula's center. This open cluster of stars, known as Collinder 26 or Melotte 15, contains a few bright stars nearly 50 times the mass of the Sun, and many more dim stars that are only a fraction of the Sun's mass.

The Heart Nebula is also made up of ionised oxygen and sulfur gasses, responsible for the rich blue and orange colours seen in narrowband images. The shape of the nebula is driven by stellar winds from the hot stars in its core. The nebula also spans almost 2 degrees in the sky, covering an area four times that of the diameter of the full moon.

Westerhout 5 (Sharpless 2-199, LBN 667, Soul Nebula) is an emission nebula located in Cassiopeia. Several small open clusters are embedded in the nebula: CR 34, 632, and 634 (in the head) and IC 1848 (in the body). The object is more commonly called by the cluster designation IC 1848.

Small emission nebula IC 1871 is present just left of the top of the head, and small emission nebulae 670 and 669 are just below the lower back area.

The galaxies Maffei 1 and Maffei 2 are both nearby the nebula, although light extinction from the Milky Way makes them very hard to see. Once thought to be part of the Local Group, they are now known to belong to their own group- the IC 342/Maffei Group.

This complex is the eastern neighbor of IC1805 (Heart Nebula) and the two are often mentioned together as the "Heart and Soul". 

The Double Cluster (also known as Caldwell 14) consists of the open clusters NGC 869 and NGC 884 (often designated h Persei and χ (chi) Persei, respectively), which are close together in the constellation Perseus. Both visible with the naked eye, NGC 869 and NGC 884 lie at a distance of about 7,500 light years in the Perseus Arm of the Milky Way galaxy.
NGC 869 has a mass of 4,700 solar masses and NGC 884 weighs in at 3,700 solar masses; both clusters are surrounded with a very extensive halo of stars, with a total mass for the complex of at least 20,000 solar masses. They form the core of the Perseus OB1 association of young hot stars.

Based on their individual stars, the clusters are relatively young, both 14 million years old. In comparison, the Pleiades have an estimated age ranging from 75 million years to 150 million years.

There are more than 300 blue-white super-giant stars in each of the clusters. The clusters are also blueshifted, with NGC 869 approaching Earth at a speed of 39 km/s (24 mi/s) and NGC 884 approaching at a similar speed of 38 km/s (24 mi/s). Their hottest main sequence stars are of spectral type B0. NGC 884 includes five prominent red supergiant stars, all variable and all around 8th magnitude: RS Persei, AD Persei, FZ Persei, V403 Persei, and V439 Persei.