IC 1805

IC 1805, the “Heart Nebula”  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 nebula's intense H-alpha 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 spans almost 2 degrees in the sky, covering an area four times that of the diameter of the full moon.  

IC 1805 (Heart Nebula), 15 october 2023, Kempen,  William Optics APO f/7, f = 770 mm 

H-alpha (8040 s),  ASI1600mm pro, gain 139, T = -10C, Image processing with PixInsight V1.8.9

Details of IC 1805 (Heart Nebula), 15 october 2023, Kempen,  William Optics APO f/7, f = 770 mm 

H-alpha (8040 s),  ASI1600mm pro, gain 139, T = -10C, Image processing with PixInsight V1.8.9

The “Heart Nebula” IC 1805 and the “Soul Nebula” IC 1848 are relatively close on the sky, covering about 8 deg. Using the Canon telelens @ f ± 90 mm, which has a larger field-of-view than the William Optics APO refractor, I obtained an image in H_alpha of both nebulae, as shown below. Additional data on O[III] were also taken during the same night, but during the image processing it turned out, that the total exposure for O[III] was too short (2520 s), and the signal was too faint.

IC 1805 (Heart Nebula, right) and IC 1848 (Soul Nebula, left), 11 october 2024, Kempen, Canon EF 70-200 mm f/4 L USM telelens, f = ± 90 mm, H-alpha (4800 s),  ASI1600mm pro, gain 139, T = -10C, Image processing with PixInsight V1.8.9