STEM

Researchers Publicly Release Photo Album of Universe

• By Dian Schaffhauser
• 01/15/15

The universe just came a little closer to Earth. A collaboration of 51 schools and laboratories have released the final set of data from a six-year program of research that used a wide-field telescope in the southwest to survey the distant universe, the Milky Way galaxy and extrasolar planetary systems. The contents of "Data Release 12" from the Sloan Digital Sky Survey (SDSS) include images and other forms of data, such as catalogs of detected objects with parameters related to positions and magnitude.

"This set of observations is one of the largest astronomical databases ever assembled," said Donald Schneider, a professor of astronomy and astrophysics at Pennsylvania State, one of the participating universities. "The more than 70 terabytes we collected during the third epoch of this survey, SDSS-III, contain information on nearly half-a-billion stars and galaxies, including three-dimensional cosmic structures that formed billions of years before the sun began to shine."

Schneider is the SDSS-III survey coordinator and the project's scientific publication coordinator. SDSS-III refers to the third phase of the survey. Phase one ran from 1998 to 2005; phase two operated from 2005 to 2008; and phase three started in 2008 and ran until mid-2014. SDSS IV will take advantage of the Sloan Foundation 2.5m Telescope at Apache Point Observatory in New Mexico for new projects, a phase that will last until 2020. That same telescope has powered all of the previous phases.

"The most astonishing feature of the SDSS is the breadth of groundbreaking research it enables," said SDSS-III Director Daniel Eisenstein of the Harvard-Smithsonian Center for Astrophysics. "We've searched nearby stars for planets, probed the history of our Milky Way and measured nine billion years of our universe's accelerated expansion. Our data also provide the first direct probe of the expansion rate of the universe 10 billion years ago."

One of the most important decisions made at the beginning of the SDSS initiative was to "release all of our data, so everyone could use it," noted Alex Szalay, a professor of astronomy at Johns Hopkins University. That institution developed the online interfaces that many users use to access the data within the SDSS database.

The survey includes an education site that provides lessons plans and activities for grades 6-12 and college.

Funding of SDSS-III was provided by the Alfred P. Sloan Foundation, the participating universities, the National Science Foundation and the United States Department of Energy Office of Science.