Measured distance within the Milky Way gives clues to what our galaxy looks like
Science News said:For the first time, astronomers have directly measured the distance to a spot clear across the galaxy. The established but challenging technique promises a new way to map the structure of the Milky Way.
This technique, called parallax, has measured distances to stars since the 1830s. But because of galactic dust in the way, it has been difficult to use parallax on stars on the opposite side of the galaxy. Other ways to measure distance are saddled with assumptions and uncertainties.
Alberto Sanna of the Max Planck Institute for Radio Astronomy in Bonn, Germany, and his colleagues used the Very Long Baseline Array of radio telescopes in New Mexico to track a star-forming region in the outer Scutum-Centaurus spiral arm, which is on the opposite side of the Milky Way from the local arm where the sun resides. The scientists report in the October 13 Science that the region is more than 66,500 light-years away.
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“We predict that, within the next 10 years, we will be able to answer the question: What does the Milky Way look like?” Sanna says.