Radio telescopes settle controversy over distance to Pleiades
Astronomers have used a worldwide network of radio telescopes to resolve a controversy over the distance to a famous star cluster — a controversy that posed a potential challenge to scientists’ basic understanding of how stars form and evolve. The new work shows that the measurement made by a cosmic-mapping research satellite was wrong.
Until the 1990s, the consensus was that the Pleiades are about 430 light-years from Earth. However, the European satellite Hipparcos, launched in 1989 to precisely measure the positions and distances of thousands of stars, produced a distance measurement of only about 390 light-years. ... “That may not seem like a huge difference, but in order to fit the physical characteristics of the Pleiades stars, it challenged our general understanding of how stars form and evolve,†said Carl Melis of the University of California, San Diego. “To fit the Hipparcos distance measurement, some astronomers even suggested that some type of new and unknown physics had to be at work in such young stars.â€