Starfield. Optical image of a starfield in the constellation Ophiuchus, the serpent bearer. North is at top. The star at centre is Zeta Ophiuchi. It is surrounded by faint red nebulosity, comprising hydrogen gas which glows as it is ionised by radiation from nearby hot stars. The Milky Way runs through the bottom left corner, providing rich starfields. It is the band of light crossing the sky formed from the millions of stars in the plane of our galaxy. Ophiuchus is best seen in summer from the northern hemisphere.