Mission Accomplished By Twin-Telescope Sky Survey Led By UMass Amherst Astronomer

AMHERST, Mass. - After scanning the entire sky and capturing breathtaking and scientifically important images of galaxies, stars, and other celestial objects, a pair of infrared telescopes has finished its survey work. For the past three and a half years, the twin telescopes of the Two Micron All-Sky Survey (2MASS), located in Arizona and Chile, have conducted the first high-resolution digital survey of the complete sky, in a project led by University of Massachusetts astronomer Michael Skrutskie. The successful completion of observations using the telescopes marks a milestone in modern astronomy, according to researchers.

"These telescopes have given us the first detailed global view of our Milky Way galaxy as well as the galaxies which lie beyond," said Skrutskie. "The resulting databases and source catalogs are a treasure trove which will be mined for discovery by scientists and the public alike for decades to come." The University of Massachusetts was responsible for the development and construction of the 2MASS telescopes and cameras and managed the collection of survey data.

The twin telescopes essentially transformed everyday desktop computers into observatories, with images from the project archived and made available online by scientists at the Infrared Processing and Analysis Center (IPAC) at the California Institute of Technology and Jet Propulsion Laboratory in Pasadena. 2MASS has collected more than 24 terabytes of images since 1997, enough to fill more than 2,000 hard drives on the average desktop computer. IPAC developed the software system that converts the raw digital data from the telescopes into striking images and catalogues useful to astronomers. UMass researcher Rae Stiening, the project manager for 2MASS, was responsible for maintaining the project budget and schedule. He also had full responsibility for maintaining the observing facilities and upgrading the hardware.

The survey has:

* uncovered numerous stars with such unique characteristics that astronomers needed to revise a century-old classification system of known types of stars;

* unveiled the coolest brown dwarfs, or failed stars, known to date;

* detected previously unknown galaxies seen behind the disk of our own Milky Way;

* mapped new star-birth regions both in our Milky Way and in other galaxies;

* discovered many new, dust-obscured active galaxies and quasars in the distant reaches of the universe that were missed by earlier surveys that used visible and ultraviolet light.

The 2MASS survey is the most thorough census ever made of our Milky Way galaxy and the nearby universe, Skrutskie explained. It detects infrared wavelengths that are beyond the red light in the rainbow of visible colors. Infrared light penetrates gas and dust more effectively than visible light, so it is particularly effective for detecting objects veiled by the Milky Way, as well as the faint heat of very cool objects that give off very little visible light of their own.

To cover the entire sky, 2MASS has used two highly automated, 1.3-meter (51-inch) diameter telescopes, one at Fred Lawrence Whipple Observatory on Mount Hopkins, Ariz., the other at the National Science Foundation-funded Cerro Tololo Inter-American Observatory in Chile. The Arizona telescope began operations in June of 1997, while the Chilean telescope began scanning the sky in March 1998. Both facilities completed their work on February 15.

"The 2MASS telescopes and cameras operated with incredible efficiency and were workhorses for more than a thousand nights," said Roc Cutri, a scientist at IPAC. "The facilities collected data 99.5 percent of the available time during the mission, and only a few nights were lost due to hardware failures. That’s a remarkable record for any astronomical observatory on the ground or in space."

Catalogues containing more than 300 million stars and galaxies extracted from the images have begun to yield significant astronomical discoveries, and will also provide an invaluable reference frame to steer NASA’s upcoming Space Infrared Telescope Facility (SIRTF).

The 2MASS project is a collaborative effort between the University of Massachusetts and IPAC. Part of NASA’s Origins Program, 2MASS is funded by NASA’s Office of Space Science and the National Science Foundation. In addition to enabling ground-breaking new scientific discoveries, 2MASS results will also benefit future Origins missions, including SIRTF and the Next Generation Space Telescope, and will also help scientists plan observations for the Hubble Space Telescope and the Stratospheric Observatory for Infrared Astronomy.

Michael Skrutskie can be reached at 413/545-2456 or skrutski@astro.umass.edu.