DISK-RELATED BURSTS AND FADES IN YOUNG STARS

作者：Findeisen Krzysztof^*; Hillenbrand Lynne; Ofek Eran; Levitan David; Sesar Branimir; Laher Russ; Surace Jason

来源：Astrophysical Journal, 2013, 768(1): 93.

DOI：10.1088/0004-637X/768/1/93

• stars: late-type
• stars: pre-main sequence
• stars: solar-type
• stars: variables: T Tauri, Herbig Ae/Be

We present first results from a new, multiyear, time domain survey of young stars in the North America Nebula complex using the Palomar Transient Factory. Our survey is providing an unprecedented view of aperiodic variability in young stars on timescales of days to years. The analyzed sample covers R-PTF approximate to 13.5-18 and spans a range of mid-infrared color, with larger-amplitude optical variables (exceeding 0.4 mag root mean squared) more likely to have mid-infrared evidence for circumstellar material. This paper characterizes infrared excess stars with distinct bursts above or fades below a baseline of lower-level variability, identifying 41 examples. The light curves exhibit a remarkable diversity of amplitudes, timescales, and morphologies, with a continuum of behaviors that cannot be classified into distinct groups. Among the bursters, we identify three particularly promising sources that may represent theoretically predicted short-timescale accretion instabilities. Finally, we find that fading behavior is approximately twice as common as bursting behavior on timescales of days to years, although the bursting and fading duty cycle for individual objects often varies from year to year.

• 出版日期2013-5-1