Letters of Intent received in 2019

LoI 2021-2081
GA Focus Meeting: Fundamental Parameters from Binaries: Commemorating 50 Years of the Wilson-Devinney Program

Date: 16 August 2021 to 27 August 2021
Category: Focus meetings (GA)
Location: Busan, Korea, Rep of
Contact: Geraldine Peters (gpeters@usc.edu)
Coordinating division: Division G Stars and Stellar Physics
Other divisions: Division B Facilities, Technologies and Data Science
Division C Education, Outreach and Heritage
Division F Planetary Systems and Astrobiology
Co-Chairs of SOC: Geraldine J. Peters (University of Southern California)
Andrej Prsa (Villanova University)
Walter Van Hamme (Florida International University)
Christos Siopis (Université Libre de Bruxelles)
Chair of LOC: None (None)



1. Historical background of the Wilson-Devinney program
2. Recent discoveries and advancements in stellar physics from Kepler/K2, CoRoT, TESS, and Gaia observations
3. New light-curve modeling techniques in the era of big data
4. Modeling pulsations in binary stars
5. Analysis software needed to interpret upcoming observations (e.g. PLATO, LSST, JWST)



It has been a half century since the first realistic modeling of binary star light curves allowed the astronomical community to extract reliable stellar parameters from photometric and spectroscopic data. The first major program toward this end was developed by Robert E. Wilson and Edward J. Devinney (ApJ, 166, 605, 1971). The Wilson-Devinney (W-D) program continues to this day to be updated and has been a starting point for several other light curve modeling codes (e.g. Phoebe), all contributing to our knowledge of basic stellar parameters that are essential for understanding stellar evolution and characterizing exoplanets. In this era of precision space photometry, the astrophysical and computational concepts implemented in the original W-D program and augmented in its subsequent versions continue to serve as the basis for analyzing and understanding light curve data. Many researchers have used the W-D program itself, or others inspired by it, to model binary light curves from the Kepler, TESS and CoRoT missions, while a dedicated team within the Europe-wide Data Processing and Analysis Consortium (DPAC) of the Gaia mission has developed software for the extraction of physical parameters of eclipsing binaries detected by Gaia which again exploits the basic concepts of the W-D program.

Updates to W-D have always been made available to the community and it is estimated to date that more than 4000 astronomers worldwide have used this program in their research. This Focus Meeting will celebrate the 50th anniversary of the W-D program. We are proposing a meeting of 1.5 days in duration. It will begin with 1-2 talks on the historical development and use of W-D. We then turn our attention to contemporary binary star modeling. Data analysis in the era of big data is featured. Examples are the archives generated by the Kepler/K2, CoRoT, TESS, and Gaia spacecraft. Included will be recent W-D capabilities such as accretion disks and the treatment of pulsations in either of the stellar components, allowing a comparison with the interior dynamics in single pulsating stars deduced from asteroseismology. We conclude with a discussion of what data will be available within the next 5 years or so, and the analysis software that must be developed to interpret these observations. Finally we will end with an assessment of what space- and ground-based missions and instruments we would like to see materialize in the future.