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.
Fariss Samarrai | Newswise Science News
Breakthrough with a chain of gold atoms
17.02.2017 | Universität Konstanz
New functional principle to generate the „third harmonic“
16.02.2017 | Laser Zentrum Hannover e.V.
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
20.02.2017 | Materials Sciences
20.02.2017 | Health and Medicine
20.02.2017 | Health and Medicine