Motivation

The availability of high-quality ground-based data and new space data (e.g., CoRoT, Kepler) in large volume is driving the development of a diverse range of analysis methods for extracting estimates of the mode parameters in solar-like stars. Some of these methods take their heritage from analyses applied to classical oscillators, others do so from analyses developed for Sun-as-a-star data, while other methods have been developed especially for application to solar-like asteroseismology.

With the current and new solar-like data we have the ability to be able to measure parameters as a function of frequency (including, of course, the mode frequencies themselves). But to what extent do we need to apply a-priori constraints to these analyses to ensure that the results are meaningful and robust? For example, one might choose to demand a certain smoothness of the parameters in frequency. If the a-priori constraints thereby applied are too severe, we risk missing important features in the results; while if the constraints are too weak, we may obtain results whose variation in frequency is unphysical and dominated by systematic limitations of the data and/or analysis.

So, where does a happy medium reside? And how does this change for different classes of star, and different datasets (e.g., quality, length etc.)?

Discussion Points

• What are the different basic methods of analysis available to us, and to what extent do they use (or are amenable to) application of a-priori constraints?
• What a-priori constraints do we apply, and why? How do these vary for different datasets, and different types of star?
• What guidance can theoreticians provide to the observers, e.g., what are sensible scales for changes in frequency to parameters such as amplitudes, linewidths, splittings, etc.? How might these "guideline scales" change from one class of star to another?
• Do different methods of analysis produce consistent results (accuracy) and similar errors (precision)?
• How should we handle mixed modes? These are scientifically interesting, but they complicate the analysis. The frequencies depart from the regular p-mode pattern, their linewidths are different (narrower?). What about rotation? How can we adapt our fitting procedures? What guidance can we get from theoreticians and how much should we rely on it?
• Extending to the realm of red giants brings additional challenges. The oscillation spectrum is more crowded and complex (although at least rotation should be very slow). Again, how can we adapt our fitting procedures?
• Fitting the background is an important step. Which methods work best to fit the background and which peak-bagging techniques are least sensitive to errors in that fit? What guidance can we get from theoreticians on the shape of the background? What measurements of from background do they need to extract science?
• Ensemble asteroseismology. How can we use the large number of stars to our advantage? What new diagrams can we invent?