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Title: YSOVAR: MID-INFRARED VARIABILITY OF YOUNG STELLAR OBJECTS AND THEIR DISKS IN THE CLUSTER IRAS 20050+2720

We present a time-variability study of young stellar objects (YSOs) in the cluster IRAS 20050+2720, performed at 3.6 and 4.5 μm with the Spitzer Space Telescope; this study is part of the Young Stellar Object VARiability (YSOVAR) project. We have collected light curves for 181 cluster members over 60 days. We find a high variability fraction among embedded cluster members of ca. 70%, whereas young stars without a detectable disk display variability less often (in ca. 50% of the cases) and with lower amplitudes. We detect periodic variability for 33 sources with periods primarily in the range of 2–6 days. Practically all embedded periodic sources display additional variability on top of their periodicity. Furthermore, we analyze the slopes of the tracks that our sources span in the color–magnitude diagram (CMD). We find that sources with long variability time scales tend to display CMD slopes that are at least partially influenced by accretion processes, while sources with short variability timescales tend to display extinction-dominated slopes. We find a tentative trend of X-ray detected cluster members to vary on longer timescales than the X-ray undetected members.
Authors:
; ;  [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ; ;  [7] ;  [8] ;  [9] ;  [10] ;  [11] ;  [12]
  1. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
  2. NASA Ames Research Center, Moffett Field, CA 94035 (United States)
  3. Western Washington University, 516 High Street, Bellingham, WA 98225 (United States)
  4. Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)
  5. Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States)
  6. Missouri State University, 901 S. National Avenue, Springfield, MO 65897 (United States)
  7. Spitzer Science Center/Caltech, 1200 E. California Boulevard, Pasadena, CA 91125 (United States)
  8. Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States)
  9. University of Vienna, Department of Astrophysics, Türkenschanzstr. 17, A-1180, Vienna (Austria)
  10. Dept. of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States)
  11. Centro de Astrobiología (INTA-CSIC), ESAC Campus, P.O. Box 78, E-28691 Villanueva de la Canada (Spain)
  12. Physics and Astronomy Department, University of Georgia, Athens, GA 30602–2451 (United States)
Publication Date:
OSTI Identifier:
22520125
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astronomical Journal (Online); Journal Volume: 150; Journal Issue: 4; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCRETION DISKS; COLOR; DIAGRAMS; PERIODICITY; PROTOPLANETS; SPACE; STAR CLUSTERS; STARS; TELESCOPES; VISIBLE RADIATION