New project to probe Milky Way history

Dark matter makes Milky Way’s stars extend their lifetimes by a billion yearsWashington, Dec 16 : A new project, led by a University of Virginia (U. Va.) professor, is all set to survey more than 100,000 Milky Way stars, in an attempt to know more about the history of our galaxy.

The project, the Apache Point Observatory Galactic Evolution Experiment, or APOGEE, is one of four experiments of the new Sloan Digital Sky Survey III, using the astronomical facilities at Apache Point Observatory in New Mexico.

"It's the ultimate exercise in archeology," said Steven Majewski, a University of Virginia professor of astronomy and lead scientist on a new project.

The project aims to survey more than 100,000 Milky Way red giant stars - bright, bloated stars in a late stage of their evolution.

"The spectra of red giant stars contain the chemical and dynamical fingerprints needed to understand the assembly of our Milky Way galaxy. Our home galaxy, the Milky Way, is a typical spiral galaxy and an important laboratory for gaining a detailed understanding of galaxies in general," Majewski said.

"APOGEE will be the first truly comprehensive study of the chemistry of Milky Way stars. With APOGEE, we will gain enormous insight to the processes that make stars and that drive the formation and evolution of galaxies," he added.

Though red giants are extremely bright, those in distant parts of the Milky Way - like the center of our galaxy 25,000 light-years away - are largely obscured by massive clouds of interstellar dust scattered across the vastness of space.

Because of these dust clouds, only a relatively small fraction of stars in the Milky Way can be observed in visible light.

U. Va. astronomer Michael Skrutskie, an expert in the design of infrared cameras and spectrographs, is leading a U. Va. team in the design and construction of a unique instrument that will provide unprecedented information about the dynamics and chemical constitution of Milky Way stars.

His highly specialized spectrograph will be connected to a 2.5-meter telescope at Apache Point, allowing for detailed observation of 300 stars simultaneously.

Majewski and other astronomers participating in the APOGEE project will observe thousands of red giants per clear night over the course of three years with the instrument.

"Currently, being able to observe 10 red giants per night at APOGEE's level of detail would be considered good," he said. (ANI)

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