Publication Date:
2014-12-14
Description:
We present multiple epochs of near-infrared spectroscopy for a sample of 25 young stars, including T Tauri, Herbig Ae/Be, and FU Ori objects. Using the FSPEC instrument on the Bok 90-inch telescope, we obtained K -band spectra of the Br transition of hydrogen, with a resolution of 3500. Epochs were taken over a span of 〉1 yr, sampling time-spacings of roughly 1 d, 1 month, and 1 yr. The majority of our targets show Br emission, and in some cases these are the first published detections. Time variability is seen in approximately half of the targets showing Br emission. We compare the observed variability with expectations for rotationally modulated accretion on to the central stars and time-variable continuum emission or extinction from matter in the inner disc. Our observations are not entirely consistent with models of rotationally modulated magnetospheric accretion. Further monitoring, over a larger number of epochs, will facilitate more quantitative constraints on variability time-scales and amplitudes, and a more conclusive comparison with theoretical models.
Print ISSN:
0035-8711
Electronic ISSN:
1365-2966
Topics:
Physics
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