Astronomers: Binary system creates tidal waves on star’s surface 3x larger than our own Sun
Based on computer simulations, astronomers believe that the monthly light changes in a binary star system are partly caused by gigantic tidal waves on the surface of the system’s larger star, waves that are three times higher than the diameter of our own Sun.
The larger star in the system is nearly 35 times the mass of the Sun and, together with its smaller companion star, is officially designated MACHO 80.7443.1718 — not because of any stellar brawn, but because the system’s brightness changes were first recorded by the MACHO Project in the 1990s, which sought signs of dark matter in our galaxy.
Most heartbeat stars vary in brightness only by about 0.1%, but MACHO 80.7443.1718 jumped out to astronomers because of its unprecedentedly dramatic brightness swings, up and down by 20%. “We don’t know of any other heartbeat star that varies this wildly,” says MacLeod.
To unravel the mystery, MacLeod created a computer model of MACHO 80.7443.1718. His model captured how the interacting gravity of the two stars generates massive tides in the bigger star. The resulting tidal waves rise to about a fifth of the behemoth star’s radius, which equates to waves about as tall as three Suns stacked on top of each other, or roughly 2.7 million miles high.
The image on the right is a screen capture from the computer simulation. The bulges on the right side of the larger star are the hypothesized tidal waves.
Based on computer simulations, astronomers believe that the monthly light changes in a binary star system are partly caused by gigantic tidal waves on the surface of the system’s larger star, waves that are three times higher than the diameter of our own Sun.
The larger star in the system is nearly 35 times the mass of the Sun and, together with its smaller companion star, is officially designated MACHO 80.7443.1718 — not because of any stellar brawn, but because the system’s brightness changes were first recorded by the MACHO Project in the 1990s, which sought signs of dark matter in our galaxy.
Most heartbeat stars vary in brightness only by about 0.1%, but MACHO 80.7443.1718 jumped out to astronomers because of its unprecedentedly dramatic brightness swings, up and down by 20%. “We don’t know of any other heartbeat star that varies this wildly,” says MacLeod.
To unravel the mystery, MacLeod created a computer model of MACHO 80.7443.1718. His model captured how the interacting gravity of the two stars generates massive tides in the bigger star. The resulting tidal waves rise to about a fifth of the behemoth star’s radius, which equates to waves about as tall as three Suns stacked on top of each other, or roughly 2.7 million miles high.
The image on the right is a screen capture from the computer simulation. The bulges on the right side of the larger star are the hypothesized tidal waves.