Milky Way doesn't end where we thought it would: Astronomers have new data

Astronomers have found 208 stars that form the edge of the Milky Way in search of the outer limits of our galaxy, the most distant of which is more than a million light-years away – almost halfway to the Andromeda galaxy.

According to Gizmodo.com, the stars discovered by scientists from the University of California, Santa Cruz, known as RR Lyra variable stars have a curious feature: their brightness can vary when observed from Earth.

These stars seem to pulsate, so they can serve as a kind of beacon, which can be used to determine how far away they are.

By calculating the distance to these stars, the team of scientists found that the farthest of the group is about halfway between the Milky Way and the Andromeda Galaxy, one of our closest cosmic neighbors.

"We used variable stars as reliable indicators for determining distances," said study leader Yuting Feng, who plans to present the findings this week at the American Astronomical Society meeting in Seattle.

The Milky Way is made up of several parts, the main one being a thin spiral disk about 100,000 light years in diameter. Our solar system is located on one of the arms of this disk. The disk is surrounded by an inner and outer halo, which contain some of the oldest stars in our galaxy.

In the past, researchers believed that the edge of our galaxy's outer halo was about 1 million light-years from its center. But a new study shows that the outer edge of the Milky Way is 40,000 light-years farther away than thought – about 1.04 million light-years from the center of the galaxy. Consequently, the distance to the Andromeda Galaxy is even shorter than previously thought.