Tidal Heat Fuels Cosmic Mysteries

Recent astronomical observations have uncovered a cohort of white dwarf binaries with unusually short orbital periods, completing orbits in under an hour. These systems exhibit unexpected characteristics, including sizes twice that predicted by standard models and surface temperatures ranging from 10,000 to 30,000 Kelvin, significantly hotter than expected for aged stellar remnants.

A research team led by Lucy Olivia McNeill at Kyoto University has developed a theoretical model to investigate the role of tidal heating in these peculiar white dwarfs. Their analysis suggests that the intense gravitational interactions within these close binary systems can generate substantial internal heat, causing the white dwarfs to expand and reach significantly higher temperatures, well above 10,000 Kelvin.

This tidal heating mechanism provides a compelling explanation for the observed size and temperature anomalies. The expanded state of these white dwarfs suggests they may initiate mass transfer at orbital periods three times longer than previously assumed. Understanding these interactions is crucial for unraveling the formation pathways of significant cosmic events such as type Ia supernovae.