PN G75.5+1.7, commonly known as the Soap Bubble Nebula, is an extremely faint planetary nebula located in the constellation Cygnus. Discovered relatively recently in 2008 by amateur astronomer Dave Jurasevich, this object is a remarkable example of how deep imaging continues to reveal previously unknown structures even in well-studied regions of the sky.
The nebula appears as a nearly perfect, spherical shell—resembling a delicate soap bubble suspended in space. This structure is formed during the late stages of a Sun-like star’s life, when the star sheds its outer layers into the surrounding space. The exposed hot core emits ultraviolet radiation, ionizing the expanding shell and causing it to glow faintly in hydrogen, oxygen, and sulfur emission lines. The symmetry of the bubble suggests a relatively uniform mass-loss process, though subtle variations in brightness hint at interactions with the surrounding interstellar medium.
What makes the Soap Bubble particularly challenging—and rewarding—to image is its extremely low surface brightness. It lies embedded within the rich and complex Cygnus region, surrounded by diffuse emission nebulae and dense star fields that can easily overwhelm its subtle signal. Careful processing and long integration times are required to isolate the faint circular structure from the background.
This image was created using a combination of narrowband (H-alpha, SII, OIII) and RGB data acquired from Arnold, CA between September 12 and October 11, 2021, with a total integration time of 21.25 hours. The narrowband data were essential in revealing the delicate shell structure, while RGB data preserves natural star color and provides context within the surrounding Milky Way field.