CSI 2264: Characterizing Young Stars in NGC 2264 with Stochastically Varying Light Curves - INSU - Institut national des sciences de l'Univers Access content directly
Journal Articles The Astronomical Journal Year : 2016

CSI 2264: Characterizing Young Stars in NGC 2264 with Stochastically Varying Light Curves

John Stauffer
  • Function : Author
Ann Marie Cody
  • Function : Author
Luisa Rebull
  • Function : Author
Lynne A. Hillenbrand
  • Function : Author
Neal J. Turner
  • Function : Author
John Carpenter
  • Function : Author
Sean Carey
Susan Terebey
  • Function : Author
María Morales-Calderón
  • Function : Author
Silvia H. P. Alencar
  • Function : Author
Pauline Mcginnis
  • Function : Author
Alana Sousa
  • Function : Author
Lee Hartmann
  • Function : Author
Nuria Calvet
  • Function : Author
Giusi Micela
  • Function : Author
Ettore Flaccomio
  • Function : Author
Inseok Song
  • Function : Author
Rob Gutermuth
  • Function : Author
David Barrado
Frederick J. Vrba
  • Function : Author
Kevin Covey
  • Function : Author
William Herbst
  • Function : Author
Edward Gillen
  • Function : Author
Marcelo Medeiros Guimarães
  • Function : Author
Herve Bouy
  • Function : Author
Fabio Favata
  • Function : Author

Abstract

We provide CoRoT and Spitzer light curves and other supporting data for 17 classical T Tauri stars in NGC 2264 whose CoRoT light curves exemplify the “stochastic” light curve class as defined in 2014 by Cody et al. The most probable physical mechanism to explain the optical variability within this light curve class is time-dependent mass accretion onto the stellar photosphere, producing transient hot spots. Where we have appropriate spectral data, we show that the veiling variability in these stars is consistent in both amplitude and timescale with the optical light curve morphology. The veiling variability is also well-correlated with the strength of the He I 6678 Å emission line, predicted by models to arise in accretion shocks on or near the stellar photosphere. Stars with accretion burst light curve morphology also have variable mass accretion. The stochastic and accretion burst light curves can both be explained by a simple model of randomly occurring flux bursts, with the stochastic light curve class having a higher frequency of lower amplitude events. Members of the stochastic light curve class have only moderate mass accretion rates. Their Hα profiles usually have blueshifted absorption features, probably originating in a disk wind. The lack of periodic signatures in the light curves suggests that little of the variability is due to long-lived hot spots rotating into or out of our line of sight; instead, the primary driver of the observed photometric variability is likely to be instabilities in the inner disk that lead to variable mass accretion.

Based on data from the Spitzer and CoRoT missions, as well as the Canada-France-Hawaii Telescope (CFHT) MegaCam CCD, and the European Southern Observatory Very Large Telescope, Paranal Chile, under program 088.C-0239. The CoRoT space mission was developed and is operated by the French space agency CNES, with particpiation of ESA’s RSSD and Science Programmes, Austria, Belgium, Brazil, Germany, and Spain. MegaCam is a joint project of CFHT and CEA/DAPNIA, which is operated by the National Research Council (NRC) of Canada, the Institute National des Sciences de l’Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii.

Dates and versions

insu-03691564 , version 1 (09-06-2022)

Identifiers

Cite

John Stauffer, Ann Marie Cody, Luisa Rebull, Lynne A. Hillenbrand, Neal J. Turner, et al.. CSI 2264: Characterizing Young Stars in NGC 2264 with Stochastically Varying Light Curves. The Astronomical Journal, 2016, 151, ⟨10.3847/0004-6256/151/3/60⟩. ⟨insu-03691564⟩
8 View
0 Download

Altmetric

Share

Gmail Facebook X LinkedIn More