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SUMMARY:Attractor reconstruction of active stellar light curves - Dr Emily
  Sandford (University of Cambridge)
DTSTART:20231128T111500Z
DTEND:20231128T120000Z
UID:TALK208132@talks.cam.ac.uk
CONTACT:David Buscher
DESCRIPTION:Stellar activity is notoriously difficult to model\, being nei
 ther periodic nor purely stochastic. In light curves\, the interplay betwe
 en the stellar rotation period and the birth and death of spots and facula
 e gives rise to quasi-periodic modulation over time scales of hours to wee
 ks. Despite the complexity of this interplay\, the resulting light curves 
 bear strong qualitative resemblance to systems known to exhibit low-dimens
 ional dynamical chaos\, such as the Rössler attractor.\n\nIn the 1980s an
 d 1990s\, a suite of techniques for nonlinear dynamical analysis\, called 
 attractor reconstruction\, evolved to study exactly this type of system. A
 ttractor reconstruction works by embedding a 1-dimensional time series\, s
 uch as stellar light curve\, in a higher-dimensional phase space capable o
 f capturing its full dynamical behavior: too low a dimensionality\, and th
 e system’s trajectory will self-intersect and tangle\, which we know to 
 be physically unrealistic given the non-periodicity of the observed signal
 . This technique has been used successfully to model the historical sunspo
 t record and the light curves of variable stars (both simulated and observ
 ed) and to recover important features of their underlying dynamics\, inclu
 ding their dimensionality and the time scales over which they can be meani
 ngfully forecast into the future. Here\, I discuss the application of attr
 actor reconstruction to the light curves of active main-sequence stars obs
 erved by Kepler\, TESS\, and ground-based surveys.\n
LOCATION:Coffee area\, Battcock Centre
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