Letters of Intent received in 2017

LoI 2019-2011
RR Lyrae 2019: Frontiers of Classical Pulsators - Theory and Observations

Topics

RR Lyrae, classical Cepheids, asteroseismology, pulsation modes, stellar pulsation, Blazhko Effect, galactic structure studies, near-field cosmology, surveys

Rationale

This is an exciting time for classical pulsator science with a wealth of data from large ground-based and space-based surveys. This letter of intent is for an IAU symposium on classical pulsating stars, namely RR Lyrae and Cepheid stars. The community of astronomers studying RR Lyrae stars have started a series of meetings, beginning in Visegrad, Hungary, in 2015. The proposed conference of this series will be for October 2019, to be held in Cloudcroft, New Mexico, USA.

The primary purpose of our conference series is to bring together astronomers from both theoretical and observational realms to discuss the latest discoveries and ongoing work with RR Lyrae and Cepheid stars. Large datasets are providing a vast wealth of information of these stars, ranging from the asteroseismology and theoretical modeling of stellar interiors, to cosmological implications by studying their populations in the Milky Way and Local Group galaxies. By 2019, many new surveys, such as LSST, Pan-STARRS, GAIA, VVV, OGLE, and TESS will be operating or coming online, and this would be an opportune time to present the latest developments and discoveries.

From Kepler, OGLE, and VVV, new questions have emerged on the classical pulsator landscape. Through Kepler, there have been new insights to a very old problem of what the Blazhko Effect is. New theoretical efforts have come forth from this problem, as well as identifying new non-radial modes in the pulsation. Data from TESS is expected to expand these studies with new asteroseismological data. Large sky surveys such as OGLE have produced amazing catalogs of variable stars found in the Galactic bulge and the Magellanic Clouds, providing the groundwork of studying the overall populations of variable stars with respect to their parent environment. Similar large scale surveys are expected through LSST, but already preliminary results have come from GAIA and Pan-STARRS.

A particularly important feature of RR Lyrae and Cepheid stars is their virtue of being on the distance ladder. The detection of these objects are crucial to any cosmological or Galactic structure studies. Additionally, understanding their pulsation cycle gives insight to their stellar interiors, and further into the stellar evolution scenarios of low mass stars. These stars are important calibrators to a variety to stellar disciplines.

The range of topics that are ongoing and for the future will be discussed the week of September 17, 2017, in Niepolomice, Poland, as this is our second meeting of the conference series. The final proposal for the IAU Symposium will reflect what was discussed during this meeting, as well as a fine tuning of topics to be discussed during the 2019 meeting.