SETI Astronomers Find Sun's Coolest Neighbors


Larry Klaes (lklaes@bbn.com)
Wed, 02 Jun 1999 15:13:14 -0400


>Date: Tue, 1 Jun 1999 13:00:09 -0700 (PDT) >From: JPL Media Relations Office <JPLNews@jpl.nasa.gov> >To: news@www.jpl.nasa.gov >Subject: Astronomers Find Sun's Coolest Neighbors >Sender: JPLNews@jpl.nasa.gov >Reply-To: news-owner@www.jpl.nasa.gov > >MEDIA RELATIONS OFFICE >JET PROPULSION LABORATORY >CALIFORNIA INSTITUTE OF TECHNOLOGY >NATIONAL AERONAUTICS AND SPACE ADMINISTRATION >PASADENA, CALIF. 91109 TELEPHONE (818) 354-5011 >http://www.jpl.nasa.gov > >Contact: Jane Platt (818) 354-0880 > >FOR IMMEDIATE RELEASE June 1, 1999 > >ASTRONOMERS FIND SUN'S COOLEST NEIGHBORS > > A pair of near-infrared telescopes sponsored by NASA and the >National Science Foundation has detected the coolest brown dwarfs >ever seen -- celestial objects that are neither fish nor fowl, or >in this case, neither planet nor star. > > Brown dwarfs are often thought of as "stellar wannabes." >They are failed stars that never got hot enough to ignite the >nuclear fusion process that makes stars shine brightly. On the >other hand, they tend to be more massive than planets and do not >form around a star, as the planets in our solar system did. > > "These latest discoveries are merging the fields of stellar >astronomy and planetary science," said Adam Burgasser, physics >graduate student at the California Institute of Technology, >Pasadena, CA. He is leading the hunt for these objects along >with Dr. Davy Kirkpatrick, senior staff scientist at the >JPL/Caltech Infrared Processing and Analysis Center. > > After sorting through millions of celestial objects, >Burgasser discovered four brown dwarfs in images taken by a pair >of 1.3-meter (51-inch) telescopes near Tucson, AZ, and at Cerro >Tololo, Chile. The telescopes, used for the Two-Micron All Sky >Survey (2MASS), study near-infrared wavelengths that can't be >seen by the naked eye. They sense heat and thus detect heat- >emitting objects like stars and galaxies normally hidden by >curtains of cold dust. In this case, the brown dwarfs are too >cold to be seen in visible wavelengths, but 2MASS was able to >detect the small amounts of heat they emit. > > Armed with this information, Michael Brown, Caltech >assistant professor of planetary astronomy, studied the objects >using the Keck Telescope atop Mauna Kea, HI, to look for the >presence of methane, a telltale chemical fingerprint of very cool >brown dwarfs. > > "Methane forms only in objects cooler than 900 degrees >Celsius (1,652 Fahrenheit)," Burgasser said. "That's only four >times hotter than the maximum setting on a conventional kitchen >oven." > > "We think these brown dwarfs are only 30 light years away," >said Kirkpatrick. "Because our telescopes can only see the >closest examples, this means the Milky Way must be brimming with >objects like these." The newly discovered brown dwarfs are >located in the constellations of Ursa Major (the Big Dipper), >Leo, Virgo, and Corvus. > > The 2MASS telescopes are in the midst of a 3-1/2-year survey >of the entire sky. The survey is designed to catalog one million >galaxies, 300 million stars, and other celestial objects >throughout our Milky Way galaxy. The 2MASS telescopes actually >discovered five methane brown dwarfs, but one of them had been >found previously by the Sloan Digital Sky Survey, also supported >by NASA and the National Science Foundation. > > The 2MASS project is based at the University of >Massachusetts, Amherst, where its principal investigator Dr. >Michael Skrutskie is a physics and astronomy professor. The >JPL/Caltech Infrared Processing and Analysis Center combines and >processes 2MASS images into usable data. > > As part of NASA's Origins Program, 2MASS is funded by NASA's >Office of Space Science and the National Science Foundation. >Results from 2MASS will benefit future Origins missions, >including Space Infrared Telescope Facility and the Next >Generation Space Telescope. JPL manages the program for NASA's >Office of Space Science, Washington, DC. JPL is a division of >the California Institute of Technology, Pasadena, CA. > > The current images, and additional 2MASS information and >images are available at the following website: > >http://www.ipac.caltech.edu/2mass > > 2MASS information and images are also available at: > >http://pegasus.phast.umass.edu > > ##### >5/28/99 JP >99-043 > >You are subscribed to the Jet Propulsion Laboratory's news listserv. >To unsubscribe, e-mail jplnews@jpl.nasa.gov . Leave the subject blank, >and type unsubscribe news in the body of the message. >



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