U.Va. to Probe Milky Way History in Sloan Digital Sky Survey III

Astronomy is a science of origins.

“It's the ultimate exercise in archeology,” said Steven Majewski, a University of Virginia professor of astronomy and lead scientist on a new project to survey more than 100,000 Milky Way red giant stars — bright, bloated stars in a late stage of their evolution.

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. APOGEE was selected as a Sloan-III project through a competitive proposal led by U.Va. astronomers.

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

“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.”

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.

Much more of our galaxy comes into view when astronomers use instruments that allow observations in the infrared. Infrared cameras and spectrographs observe light at wavelengths longer than visible light, allowing astronomers to peer through interstellar dust to detect the chemical makeup of stars and to calculate their motions and distances.

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,” Majewski said.

U.Va. is trading expertise – and the new spectrograph – for membership in the Sloan Digital Sky Survey III project, which is operated by the Astronomical Research Consortium, a group of universities conducting research at Apache Point Observatory. The $36 million Sloan-III project is supported by the Sloan Foundation, federal agencies such as the National Science Foundation and Department of Energy, and by member institutions.

Skrutskie previously was principal investigator for the Two-Micron All Sky Survey, a major project that surveyed the entire sky in the infrared, providing a database of more than a billion stars and galaxies for astronomers to peruse.

That survey is helping Majewski to identify the 100,000 red giants the U.Va. team will investigate in much greater detail using Skrutskie's new spectrograph.

“APOGEE will inevitably create a lasting legacy of discovery,” said U.Va. astronomy department chairman John Hawley.

Other projects of the Sloan-III survey, carried out by teams of astronomers from an international collaboration of universities and research organizations, will attempt to detect the effects of dark energy; map the stars of the Milky Way halo, and search for evidence of planets orbiting a sampling of 11,000 nearby stars.

The preceding Sloan-I and Sloan-II surveys have been widely regarded as the highest-impact astronomical projects of their time.

Media Contact

Fariss Samarrai Newswise Science News

More Information:

http://www.virginia.edu

All latest news from the category: Physics and Astronomy

This area deals with the fundamental laws and building blocks of nature and how they interact, the properties and the behavior of matter, and research into space and time and their structures.

innovations-report provides in-depth reports and articles on subjects such as astrophysics, laser technologies, nuclear, quantum, particle and solid-state physics, nanotechnologies, planetary research and findings (Mars, Venus) and developments related to the Hubble Telescope.

Back to home

Comments (0)

Write a comment

Newest articles

New yttrium-hydrogen compounds discovered

Researchers at the University of Bayreuth have made a significant scientific breakthrough by discovering new yttrium-hydrogen compounds having serious implications for the research on high-pressure superconductivity. High-pressure superconductivity refers to…

New AI model detects ninety percent of lymphatic cancer cases

Medical image analysis using AI has developed rapidly in recent years. Now, one of the largest studies to date has been carried out using AI-assisted image analysis of lymphoma, cancer…

UTA preps giant particle detectors for neutrino project

Excavation of caverns part of Fermilab’s Deep Underground Neutrino Experiment. With excavation work complete at the site where four gigantic particle detectors for the international Deep Underground Neutrino Experiment (DUNE) will be…

Partners & Sponsors