Project M
Unveiling the missing population of accreting white dwarfs
Anna Pala, Adam Rubin & Rosita Kokotanekova
The observations of binaries have been fundamental to two major breakthroughs in physics: the discovery of dark energy and the first detection of gravitational waves. Yet, our understanding of binary evolution is still fragmentary, as revealed by the predicted but undetected population of old accreting white dwarfs. Work with us to shed light on these enigmatic systems.
White dwarfs represent the final state of the life of Sun-like stars after they have exhausted their nuclear fuel. A fraction of the white dwarfs in our Galaxy are found in binaries called cataclysmic variables (CVs), where the white dwarf is gravitationally bound to a stellar companion similar to the Sun. In this extremely compact configuration, the white dwarf is accreting matter from its companion and slowly devours it. Theoretical models suggest that the Galactic CV population should be dominated by old systems in which the companions have been eroded down to a mass comparable to that of Jupiter. Yet, only a handful of these highly evolved systems have been discovered so far. Unambiguously identifying this population of old CVs is essential in order to validate a fundamental prediction of the current models of binary evolution.
The Compact binary HIgh CAdence Survey (CHiCaS) is the first systematic attempt to find these elusive systems. By recording the "light curves" for more than one million objects, i.e. their variability in brightness as a function of time, CHiCaS will allow to identify those old CVs that are seen sufficiently close to edge-on that the white dwarf is eclipsed by its much larger companion.
In this project, you will work on the analysis of the CHiCaS data, looking in particular for eclipsing CVs but also identifying and characterising all the other exotic objects that have being detected by the survey, such as pulsating stars, different kinds of eclipsing binaries, flaring stars and asteroids.
#photometry #eclipses #binaries #python
