A Tour of GK Persei

Narrator (April Hobart, CXC): In Hollywood blockbusters, explosions are often among the stars of the show. In space, explosions of actual stars are a focus for scientists who hope to better understand the lifecycle of their births, lives, and deaths. Using NASA's Chandra X-ray Observatory, astronomers have studied one particular explosion that may provide clues to the dynamics of other, much larger stellar eruptions. A team of researchers pointed the telescope at GK Persei, an object that became a sensation in the astronomical world in 1901 when it suddenly appeared as one of the brightest stars in the sky for a few days, before gradually fading away. Today, astronomers cite GK Persei as an example of a "classical nova," an outburst produced by a thermonuclear explosion on the surface of a white dwarf star, the dense remnant of a Sun-like star. Classical novas can be considered to be "miniature" versions of supernova explosions that signal the destruction of an entire star and can be so bright that they outshine the whole galaxy where they are found. Although the remnants of supernovas are much more massive and energetic than classical novas, some of the fundamental physics is the same. And since classical novas can evolve much more quickly than supernovas, astronomers can use them to study how these explosions change over time. In the case of GK Persei, astronomers were able to compare Chandra observations from 2000 and again nearly 14 years later. This information allows astronomers to observe changes in key properties of the expanding debris field from the nova, giving more insight to how these explosions contribute to the cosmic ecology.