Going the Distance: Scientists Settle Pleiades Controversy

Astronomers may have finally settled a long-standing controversy when it comes to the Pleiades, a famous star cluster. They've accurately measured the distance from our planet to the star cluster - within one percent - which may correct models of star formation.

More commonly known as the "Seven Sisters" star cluster, the Pleiades are made up of hundreds of young, hot stars formed about 100 million years ago. Located in the constellation Taurus, these stars have served as a foundation for understanding how similar star clusters form.

In the past, researchers believed that the Pleiades were about 430 light-years from Earth. However, new research indicates that the distance is 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," Carl Melis, one of the researchers, said in a news release. "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."

So researchers decided to measure this distance once more. Using a global network of radio telescopes, Melis and his colleagues achieved the most accurate distance measurement yet - the equivalent of "measuring the thickness of a quarter in Los Angeles as seen from New York," researcher Amy Miouduszewski explained.

They observed several Pleiades stars over about a year and a half in order to make these precise measurements, and examined the apparent shift in each star's position caused by the Earth's rotation around the Sun.

The results revealed that the distance to the Pleiades is in reality 443 light-years, which is accurate to within one percent. This precise measurement gives researchers the information they need to work on future scientific models.

Many ancient cultures, including Native Americans, used the Pleiades as a test of vision. The more Pleiades stars one can discern - typically five to nine - the better one's vision.

"Now we've used a system that provides modern astronomy's sharpest 'vision' to solve a longstanding scientific debate about the Pleiades themselves," added Melis.

The findings were published in the journal Science.