A MISTery of Long Secondary Periods in Pulsating Red Giants - Traces of Exoplanets?

Introduction

Exoplanetary science is one of the most studied and challenging areas of modern astrophysics. Various planet detection techniques have allowed astronomers to discover over 4,500 extrasolar planets in our Galaxy, providing important constraints for testing planet formation theories.

Current Limitations

However, with the currently available methods, it is still impossible to find planets in the far regions of the Milky Way and in other galaxies. In consequence, we still cannot answer fundamental questions of exoplanetary science such as:

1. How are planets distributed in our and other galaxies?
2. How does their occurrence rate depend on the chemical content and density of their environments?

Therefore, it is urgent to find a new method of planet detection that will allow us to discover faraway planets and thus open new horizons for exoplanetary studies.

Proposed Method

Here I propose to develop such a method. I will use a class of abundant bright giant stars that exhibit long secondary periods (LSPs) as traces of extrasolar planets. These stars are binary systems, in which the companion is substellar and is submerged in a dusty cloud.

The hypothesis is that the companion is a former planet that accreted enough matter from the host star to become a brown dwarf. I will use the high-quality photometric and spectroscopic data of LSPs from large-scale surveys and combine them with modern hydrodynamical simulations to verify this hypothesis.

Potential Impact

If successful, the novel method will revolutionize the field of exoplanet detection by allowing us to find extrasolar planetary systems beyond our neighborhood, and especially in other galaxies, which is impossible with the current techniques.

Next Steps

In the next step, I will apply this novel method to hundreds of thousands of LSP variables from the OGLE catalogs of the Milky Way and the Magellanic Clouds to investigate the distribution of planets in different chemical and dynamical environments, and thus provide completely new constraints for planet formation theories.