The telescope remains the same, but with the help of new instruments designed to better see the stars, scientists can learn to see the structure of the Milky Way in a new light.
Scientists working together in the Sloan Digital Sky Survey III — including Penn State Department Head and Distinguished Professor of Astronomy and Astrophysics Donald Schneider — discovered that high velocity stars in the center of the Milky Way Galaxy are moving together in a bar-like structure.
Part of the SDSS is to “find new scientific questions the telescope can address,” said Schneider, Survey Coordinator and Scientific Publications Coordinator for the SDSS-III.
As technology is evolving, scientists are able to give new instruments to the telescope, Schneider said.
“For the first time, we can study the motion of stars in detail,” said David Nidever, a Dean B. McLaughlin Fellow at the University of Michigan in the Department of Astronomy.
The team’s Apache Point Observatory Galactic Evolution Experiment attached a new infrared spectrograph to the 2.5-meter Sloan Foundation Telescope in New Mexico.
Previously, it has been difficult to observe the stars in the Galaxy in optical light because there is a lot of dust in the inner galaxy by the bar, which blocks the star light, said Gail Zasowski, a National Science postdoctoral fellow at the Ohio State University.
But, by using the infrared spectrograph, the infrared wavelengths can shine through the dust, she said.
The spectrograph takes light from the star and spreads it out into a spectrum, and from that, the velocity and chemical compositions in stars can be obtained, Schneider said. The spectrograph can measure about 250 stars at once, he said.
Data from the first few months of APOGEE included measurements of 4,700 stars near galactic centers, Schneider said.
Ten percent of the stars were sitting in high velocity peaks, Zasowski said.
But the telescope in New Mexico can only collect data for half of the galaxy. In order to collect data for the other half of the galaxy, a telescope would have to be placed in the Southern Hemisphere, Nidever said.
Plans are under way to begin building a duplicate telescope to place in Chile for the fourth generation of the SDSS, Schneider said.
