galaxy illustration

NGC 7023 – the Iris Nebula From stardust to stardust - it’s the cycle of the universe. Located in the constellation of Cepheus (a king in Greek mythology, married to Cassiopeia and father of Andromeda – both also constellations), the gases and clouds of cosmic dust in this region are providing the raw materials for star creation. The Iris Nebula is a reflection nebula meaning that the illumination source is generally young, bright blue stars, hence the blue coloration. This is in contrast to emission nebulae, which are lit by the ionization of gases such as hydrogen, oxygen and sulfur. NGC 7023 was discovered by Sir William Herschel in 1794. SAO 19158 (or HD 200775) is the blue-dwarf star at the center of the nebula that spans six light years and source of the illumination. It’s estimated to be six times the mass of the sun, but only 10,000 years old – a newborn in the realm of stars! It exhibits slight variability, and according to published research it also displays evidence of being a binary system, a common occurrence. Due to the active star formation and the nebula’s proximity at only 1300 light years from us, the area is studied extensively by scientists. This is a stacked composite of 66 x 5 minute exposures for a total exposure of 5.5 hours.