Ysovar: The First Sensitive, Wide-area, Mid-infrared Photometric Monitoring of the Orion Nebula Cluster

Author(s)
M. Morales-Calderón, J. R. Stauffer, L. A. Hillenbrand, R. Gutermuth, I. Song, L. M. Rebull, P. Plavchan, J. M. Carpenter, B. A. Whitney, K. Covey, C. Alves de Oliveira, E. Winston, M. J. McCaughrean, J. Bouvier, S. Guieu, F. J. Vrba, J. Holtzman, F. Marchis, J. L. Hora, L. H. Wasserman, S. Terebey, T. Megeath, E. Guinan, J. Forbrich, N. Huélamo, P. Riviere-Marichalar, D. Barrado, K. Stapelfeldt, J. Hernández, L. E. Allen, D. R. Ardila, A. Bayo, F. Favata, D. James, M. Werner, K. Wood
Abstract

We present initial results from time-series imaging at infrared wavelengths of 0.9 deg2 in the Orion Nebula Cluster (ONC).During Fall 2009 we obtained 81 epochs of Spitzer 3.6 and 4.5 μm data over 40 consecutive days. We extracted light curves with ~3% photometric accuracy for ~2000 ONC members ranging from several solar masses down to well below the hydrogen-burning mass limit. For many of the stars, wealso have time-series photometry obtained at optical (Ic )and/or near-infrared (JK s ) wavelengths. Our data set can be mined to determine stellar rotation periods, identify new pre-main-sequence eclipsing binaries, search for new substellar Orion members, and help better determine the frequency of circumstellar disks as a function of stellar mass in the ONC. Our primary focus is the unique ability of 3.6 and 4.5 μm variability information to improve our understanding of inner disk processes and structure in the Class I and II young stellar objects (YSOs). In this paper, we provide a brief overview of the YSOVAR Orion data obtained in Fall 2009 and highlight our light curves for AA-Tau analogs—YSOs with narrow dips in flux,most probably due to disk density structures passing through our line of sight. Detailed follow-up observations are needed in order to better quantify the nature of the obscuring bodies and what this implies forthe structure of the inner disks of YSOs.

Organisation(s)
Department of Astrophysics
External organisation(s)
Spanish National Research Council (CSIC), Space Science Institute, California Institute of Technology (Caltech), National Optical Astronomy Observatory, Tucson, University of Toledo, University of California, Berkeley, University of Massachusetts, Amherst, Harvard-Smithsonian Center for Astrophysics, European Southern Observatory (Germany), Observatoire des sciences de l'univers de Grenoble, Smith College, University of Georgia, Cornell University, Boston University, University of Exeter, Science and Operations Department - Science Division (SCI-SC), Université Joseph-Fourier (Grenoble-I), US Naval Observatory, Flagstaff Station, New Mexico State University, SETI Institute, Lowell Observatory, California State University, Los Angeles, Villanova University, Centro de Investigaciones de Astronomía, Venezuela, University of Hawaii at Hilo, Cerro Tololo InterAmerican Observatory (CTIO), University of St. Andrews
Journal
The Astrophysical Journal: an international review of astronomy and astronomical physics
Volume
733
No. of pages
9
ISSN
0004-637X
DOI
https://doi.org/10.1088/0004-637X/733/1/50
Publication date
05-2011
Peer reviewed
Yes
Austrian Fields of Science 2012
103004 Astrophysics
Keywords
Portal url
https://ucrisportal.univie.ac.at/en/publications/ysovar-the-first-sensitive-widearea-midinfrared-photometric-monitoring-of-the-orion-nebula-cluster(651c3b31-f372-4bca-9502-a6326cd4c4e3).html