Giants eating giants: Mass loss and giant planets modifying the luminosity of the Tip of the Giant Branch

Understand

During the red giant phase, stars loose mass at the highest rate since birth.

• The mass-loss rate is not fixed, but varies from star-to-star by up to 5\%, resulting in variations of the star's luminosity at the tip of the red giant branch (TRGB).
• Also, most stars, during this phase, engulf part of their planetary system, including their gas giant planets and possibly brown dwarfs.
• Gas giant planet masses range between 0.1 to 2\% of the host star mass.