The Herschel DIGIT Survey of Weak-line T Tauri stars: ? implications for disk evolution and dissipation Lucas A. Cieza1, Johan Olofsson2, Paul M. Harvey3, Neal J. Evans II3, Joan Najita4, Thomas Henning2, Bruno Mer´ın5, Armin Liebhart6, Manuel G¨udel6, and Jean-Charles Augereau7
[email protected] Received ; accepted ? Herschel is an ESA space observatory with science instruments provided by European- led Principal Investigator consortia and with important participation from NASA. Based in part on observations made with the CFHT, under program 11AH96 1Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822. Sagan Fellow,
[email protected] 2Max Planck Institut fur Astronomie, Konigstuhl 17, 69117, Heidelberg, Germany 3Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 4National Optical Astronomy Observatory, 950 N. Cherry Avenue, Tucson, AZ 86719, USA 5Herschel Science Centre, European Space Agency (ESAC), P.O. Box, 78, 28691 Vil- lanueva de la Ca~nada,Madrid, Spain 6Deptartment of Astronomy, Univ. of Vienna, T¨urkenschanzstr, 17, A-1180 Vienna, Austria 7Laboratoire d0Astrophysique de Grenoble, CNRS, Universit´eJoseph-Fourier, UMR 5571, Grenoble, France { 2 { To appear in ApJ { 3 { ABSTRACT As part of the \Dust, Ice, and Gas In Time (DIGIT)" Herschel Open Time Key Program, we present Herschel photometry (at 70, 160, 250, 350 and 500 µm) of 31 Weak-Line T Tauri stars (WTTSs) in order to investigate the evolutionary status of their circumstellar disks. Thirteen stars in our sample had circumstellar disks previously known from infrared observations at shorter wavelengths, while eighteen of them had no previous evidence for a disk.