Giant star Zeta Ophiuchi makes waves
Like a ship navigating through still waters, the giant star Zeta Ophiuchi is speeding through space, generating waves in the stellar dust ahead.
As you can see in the image below, NASA's Spitzer Space Telescope managed to capture a dramatic, infrared portrait of these glowing waves, also known as the bow shock phenomenon.
Astronomers theorize that this star was once sitting pretty next to a companion star even larger than itself.
But when that star exploded, Zeta Ophiuchi was kicked away and sent flying. Indeed, Zeta Ophiuchi, which is 20 times more massive and 80,000 times brighter than our sun, is racing along at a staggering 54,000 mph, or 24 kilometers per second.
In this view, infrared light that we can't see with our human eyes has been assigned appropriate visible colors.
Zeta Ophiuchi appears as the bright blue star at center. As it charges through the dust, which appears green, fierce stellar winds push the material into waves. Where the waves are the most compressed, and the warmest, they appear red.
Bow shock is perhaps analogous to the ripples that precede the bow of a ship as it moves through the water, or the pileup of air ahead of a supersonic airplane that results in a sonic boom.