CSI 2264: CHARACTERIZING YOUNG STARS IN NGC 2264 WITH SHORT-DURATION PERIODIC FLUX DIPS IN THEIR LIGHT CURVES

Journal Article · Wed Apr 15 04:00:00 EDT 2015 · Astronomical Journal (Online)

DOI:https://doi.org/10.1088/0004-6256/149/4/130· OSTI ID:22520199

Stauffer, John; Cody, Ann Marie; Rebull, Luisa; Plavchan, Peter; Carey, Sean ^[1]; McGinnis, Pauline; Alencar, Silvia H. P. ^[2]; Hillenbrand, Lynne A.; Carpenter, John ^[3]; Turner, Neal J. ^[4]; Terebey, Susan ^[5]; Morales-Calderón, María ^[6]; Bouvier, Jerome; Venuti, Laura ^[7]; Hartmann, Lee; Calvet, Nuria ^[8]; Micela, Giusi; Flaccomio, Ettore ^[9]; Song, Inseok ^[10]; Gutermuth, Rob ^[11] ; others, and

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1. Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States)
2. Departamento de Física—ICEx—UFMG, Av. Antônio Carlos, 6627, 30270-901, Belo Horizonte, MG (Brazil)
3. Astronomy Department, California Institute of Technology, Pasadena, CA 91125 (United States)
4. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)
5. Department of Physics and Astronomy, 5151 State University Drive, California State University at Los Angeles, Los Angeles, CA 90032 (United States)
6. Centro de Astrobiología, Dpto. de Astrofísica, INTA-CSIC, PO BOX 78, E-28691, ESAC Campus, Villanueva de la Cañada, Madrid (Spain)
7. Université de Grenoble, Institut de Planétologie et d’Astrophysique de Grenoble (IPAG), F-38000 Grenoble (France)
8. Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48105 (United States)
9. INAF—Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, I-90134, Palermo (Italy)
10. Department of Physics and Astronomy, The University of Georgia, Athens, GA 30602–2451 (United States)
11. Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States)

We identify nine young stellar objects (YSOs) in the NGC 2264 star-forming region with optical CoRoT light curves exhibiting short-duration, shallow periodic flux dips. All of these stars have infrared excesses that are consistent with their having inner disk walls near the Keplerian co-rotation radius. The repeating photometric dips have FWHMs generally less than 1 day, depths almost always less than 15%, and periods (3 < P < 11 days) consistent with dust near the Keplerian co-rotation period. The flux dips vary considerably in their depth from epoch to epoch, but usually persist for several weeks and, in two cases, were present in data collected in successive years. For several of these stars, we also measure the photospheric rotation period and find that the rotation and dip periods are the same, as predicted by standard “disk-locking” models. We attribute these flux dips to clumps of material in or near the inner disk wall, passing through our line of sight to the stellar photosphere. In some cases, these dips are also present in simultaneous Spitzer IRAC light curves at 3.6 and 4.5 microns. We characterize the properties of these dips, and compare the stars with light curves exhibiting this behavior to other classes of YSOs in NGC 2264. A number of physical mechanisms could locally increase the dust scale height near the inner disk wall, and we discuss several of those mechanisms; the most plausible mechanisms are either a disk warp due to interaction with the stellar magnetic field or dust entrained in funnel-flow accretion columns arising near the inner disk wall.

• OSTI ID: 22520199
• Journal Information: Astronomical Journal (Online), Journal Name: Astronomical Journal (Online) Journal Issue: 4 Vol. 149; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COMPARATIVE EVALUATIONS
DIAGRAMS
INTERSTELLAR MAGNETIC FIELDS
PERIODICITY
PHOTOMETRY
PHOTOSPHERE
ROTATION
STAR CLUSTERS
STAR EVOLUTION
STAR MODELS
STARS
VISIBLE RADIATION