Letters of Intent received in 2022

LoI 2024-2163
GA Symposium: Understanding stellar physics through stellar variability

Date: 12 August 2024 to 16 August 2024
Category: GA Symposium
Location: Cape Town, South Africa
Contact: Warrick Ball (W.H.Ball@bham.ac.uk)
Coordinating division: Division G Stars and Stellar Physics
Other divisions:
Chair of SOC: Warrick Ball (University of Birmingham)
Chair of LOC: None (None)



stellar structure and evolution
binary and multiple stars
eruptive variables and transients
stellar pulsations and asteroseismology
the solar-stellar connection
citizen science
future ground- and space-based observatories and surveys



Stellar variability has long been a critical source of information through which we understand the basic properties of stars. We are currently in the middle of a deluge of data on stellar variability, supplied both by space-based photometry missions like (e.g. CoRoT, BRITE, Kepler, TESS) and long-term ground-based surveys (e.g. OGLE, ASAS-SN, SuperWASP, ZTF). These have allowed an enormous number of precise measurements of many kinds of stellar variability, including pulsations, transients and eclipses. Many of these observatories and surveys are new; many complement or extend previous studies and surveys; and many more are planned (e.g. PLATO, Roman, Rubin).

The catalogues of light curves and inferred variability are also arriving at a time when we can consistently characterise many of the stars with precise photometry and spectroscopy from ESA's Gaia mission and ground-based spectroscopic surveys. Many of these missions and surveys (including Gaia) are providing epoch information, from which yet more can be learned. As time goes on, so these long-term ground-based campaigns and combined data from multiple telescopes will also allow us to study variability on a longer time scale than any one space mission.

The deluge offers an unprecedented opportunity to better understand both the processes that cause the variability as well as the physics of the stars themselves. The core question of this symposium is:

What can we learn about stellar physics by studying stellar variability?

The objective is not simply to survey what variability has been observed but rather to ask (and perhaps even answer!) questions about how we can use the variability to understand the stars. Just a few examples might be

* How have precise stellar parameter parameters refined our understanding of instability regions?
* What can flares tell us about the magnetic fields of cool dwarfs?
* What have we learned about angular momentum transport from stellar pulsations?

The symposium will feature sessions on different classes of variability, including (but not limited to) eclipsing binaries/multiples, pulsations and transients/eruptive. We also plan sessions on discussing how to best use future data and observatories, and what kinds of variability would be best supported by novel observing campaigns. Finally, the symposium, which would take place at the General Assembly in 2024, would also highlight the role of publicly-available data and open source tools in analyses stellar variability. The programme will include a number of hands-on workshops for using these data and tools and space for presentations by or using citizen science projects.