The Iris Nebula, NGC lies light-years away in the constellation Cepheus. Atoms floating in the interstellar medium, including carbon and silicon, combine into tiny particles about the dimension of a visible light wave, causing scattering of light.
From : Mt Lemmon Sky Center credit : Adam Block/Mt Lemmon Sky Center/University of Arizona * Abell 33 * This is an unusual planetary nebula in that it has an almost perfect spherical shell. It is found in the constellation Hercules
A Ghost in Cepheus Described as a "dusty curtain" or "ghostly apparition," mysterious reflection nebula VdB 152 really is very faint. Far from your neighborhood on this Halloween Night, the cosmic phantom is nearly light-years away.
Zoomed out farther, the Ring reveals thin, dim outer shells that the central star threw off before it performed its more radical final disrobing. Many other planetary nebulae display similar outer halos in various flowery shapes. The halos here were composited into the image from deep exposures taken with the Large Binocular Telescope in Arizona. NASA / ESA / C. Robert O’Dell / David Thompson