Mar. 11, 2011 Just as some drivers obey the speed limit while
others treat every road as if it were the Autobahn, some stars
move through space faster than others. NASA's Wide-field
Infrared Survey Explorer, or WISE, captured this image of the
star Alpha Camelopardalis, or Alpha Cam, in astronomer-speak,
speeding through the sky like a motorcyclist zipping through
rush-hour traffic. The supergiant star Alpha Cam is the bright
star in the middle of this image, surrounded on one side by an
arc-shaped cloud of dust and gas -- a bow shock -- which is
colored red in this infrared view. Such fast-moving stars are
called runaway stars. The distance and speed of Alpha Cam is
somewhat uncertain. It is probably somewhere between 1,600 and
6,900 light-years away and moving at an astonishing rate of
somewhere between 680 and 4,200 kilometers per second (between
1.5 and 9.4 million mph). It turns out that WISE is particularly
adept at imaging bow shocks from runaway stars. Previous
examples can be seen around Zeta Ophiuch