YSOVAR: THE FIRST SENSITIVE, WIDE-AREA, MID-INFRARED PHOTOMETRIC MONITORING OF THE ORION NEBULA CLUSTER

Journal Article · Fri May 20 00:00:00 EDT 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/733/1/50· OSTI ID:21576787

Morales-Calderon, M; Stauffer, J R; Rebull, L M ^[1]; Hillenbrand, L A; Carpenter, J M ^[2]; Gutermuth, R ^[3]; Song, I ^[4]; Plavchan, P ^[5]; Whitney, B A ^[6]; Covey, K ^[7]; De Oliveira, C Alves ^[8]; Winston, E; McCaughrean, M J ^[9]; Bouvier, J ^[10]; Guieu, S ^[11]; Vrba, F J ^[12]; Holtzman, J ^[13]; Marchis, F ^[14]; Hora, J L ^[15]

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1. Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States)
2. Astronomy Department, California Institute of Technology, Pasadena, CA 91125 (United States)
3. Five College Astronomy Department, Smith College, Northampton, MA 01063 (United States)
4. Department of Physics and Astronomy, University of Georgia, Athens, GA 30602 (United States)
5. NASA Exoplanet Science Institute, California Institute of Technology, Pasadena, CA 91125 (United States)
6. Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301 (United States)
7. Department of Astronomy, Cornell University, 226 Space Sciences Building, Ithaca, NY 14853 (United States)
8. Laboratoire d'Astrophysique de Grenoble, Observatoire de Grenoble, 38041 Grenoble Cedex 9 (France)
9. Astrophysics Group, College of Engineering, Mathematics, and Physical Sciences, University of Exeter (United Kingdom)
10. UJF-Grenoble 1/CNRS-INSU, Institut de Planetologie et d'Astrophysique de Grenoble (IPAG) UMR 5274, Grenoble, F-38041 (France)
11. European Southern Observatory, Alonso de Cordova 3107, Vitacura, Santiago (Chile)
12. U.S. Naval Observatory, Flagstaff Station, 10391 W. Naval Observatory Road, Flagstaff, AZ 86001-8521 (United States)
13. New Mexico State University, Box 30001/MSC 4500, Las Cruces, NM 88003 (United States)
14. Department of Astronomy, UC Berkeley, 601 Campbell Hall, Berkeley, CA 94720 (United States)
15. Harvard-Smithsonian Center of Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

We present initial results from time-series imaging at infrared wavelengths of 0.9 deg{sup 2} in the Orion Nebula Cluster (ONC). During Fall 2009 we obtained 81 epochs of Spitzer 3.6 and 4.5 {mu}m data over 40 consecutive days. We extracted light curves with {approx}3% photometric accuracy for {approx}2000 ONC members ranging from several solar masses down to well below the hydrogen-burning mass limit. For many of the stars, we also have time-series photometry obtained at optical (I{sub c} ) and/or near-infrared (JK{sub 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 {mu}m 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 for the structure of the inner disks of YSOs.

• OSTI ID: 21576787
• Journal Information: Astrophysical Journal, Vol. 733, Issue 1; Other Information: DOI: 10.1088/0004-637X/733/1/50; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
MONITORING
NEBULAE
PHOTOMETRY
ROTATION
STARS
MOTION