IC 4604, Rho Ophiuchi Cloud Complex

IC 4604 Rho Ophiuchi Cloud Complex,  The many spectacular colors of the Rho Ophiuchi (oh’-fee-yu-kee) clouds highlight the many processes that occur there. The Rho Ophiuchi cloud complex is some 400 light-years distant near the southern edge of the constellation Ophiuchus which is low in the summer Milky Way sky. The view spans about 5 light-years at that estimated distance. The view in the sky is 4.5 x 5.5 degrees which is roughly 10 moon diameters. An exploration of the region in penetrating infrared light has detected some 300 emerging and newly formed stars whose average age is estimated to be a mere 300,000 years — extremely young compared to the Sun’s 5 billion year age. The blue regions shine primarily by reflected light. Blue light from the Rho Ophiuchi star system and nearby stars reflects more efficiently off this portion of the nebula than red light. The red and yellow regions shine primarily because of emission from the nebula’s atomic and molecular gas. Light from nearby blue stars – more energetic than the bright star Antares in the yellow region – knocks electrons away from the gas, which then shines when the electrons recombine with the gas. The dark brown are caused by dust grains – born in young stellar atmospheres – which effectively block light emitted behind them. The Rho Ophiuchi star clouds, well in front of the globular cluster Messier 4 visible here on the upper right, are even more colorful than humans can see – the clouds emits light in every wavelength band from the radio to gamma ray. The data for this image was collected in New South Wales, Australia in a 121mm telescope using a one shot color camera which collected 48 10 minutes exposures.