Asteroseismic determination of fundamental parameters of Sun-like stars using multilayered neural networks,
Monthly Notices of the Royal Astronomical Society, Volume 461, Issue 4
The advent of space-based observatories such as Convection, Rotation and planetary Transits (CoRoT) and Kepler has enabled the testing of our understanding of stellar evolution on thousands of stars. Evolutionary models typically require five input parameters, the mass, initial helium abundance, initial metallicity, mixing length (assumed to be constant over time), and the age to which the star must be evolved. Some of these parameters are also very useful in characterizing the associated planets and in studying Galactic archaeology. How to obtain these parameters from observations rapidly and accurately, specifically in the context of surveys of thousands of stars, is an outstanding question, one that has eluded straightforward resolution. For a given star, we typically measure the effective temperature and surface metallicity spectroscopically and low-degree oscillation frequencies through space observatories.
Here we demonstrate that statistical learning, using artificial neural networks, is successful in determining the evolutionary parameters based on spectroscopic and seismic measurements. Our trained networks show robustness over a broad range of parameter space, and critically, are entirely computationally inexpensive and fully automated. We analyse the observations of a few stars using this method and the results compare well to inferences obtained using other techniques. This method is both computationally cheap and inferentially accurate, paving the way for analysing the vast quantities of stellar observations from past, current, and future missions.
Key words: stars: fundamental parameters / stars: interiors / stars: low-mass / stars: oscillations / stars: solar-type