Space Desert

In order to find out more about how the universe formed, astronomers are continuously looking for ways to better observe the distribution of stars throughout the galaxy. One obstacle in doing this effectively (apart from the obvious distance challenge) is the fact that interstellar dust is usually in the way, blocking our view and making efforts futile despite significant advancements in telescopes all over the world.

We have come a long way to overcome this difficulty.

One team, led by Noriyuki Matsunaga of the University of Tokyo, used near-infrared observations from a telescope in South Africa to seek out Cepheids in an effort to add them up to our existing map of the Milky Way Galaxy. Cepheids are young stars that are only a few tens of millions of years old that burn and dim periodically, and it is this light that astronomers use to determine their distance from us.

What the team found was completely unexpected: nothing—a vast expanse of nothing. While there are cepheids in the 150 light-year center of the galaxy, it is surrounded by a stellar void stretching out to 8,000 light-years from that center point. This is enormous, considering the Milky Way is 100,000 light-years across. That’s 8% of the galaxy!

Strange void. University of Tokyo.

The Birth of a New...Debate!

"The current results indicate that there has been no significant star formation in this large region over hundreds of millions of years," said team member Giuseppe Bono from the University of Rome II in Italy. "The movement and the chemical composition of the new Cepheids are helping us to better understand the formation and evolution of the Milky Way."

This desert, called the Extreme Inner Disk, echoes what other previous radio astronomy studies found. "Our conclusions are contrary to other recent work, but in line with the work of radio astronomers who see no new stars being born in this desert," says Michael Feast, team member of the study from the University of Cape Town in South Africa.

What caused this desert region, however, is another matter altogether, and will definitely be sparking another scientific debate—the floor is now open for wild theories.


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