Discover a planet that cannot exist in reality

About the episode

Astronomers, to their own astonishment, have discovered a planet much larger than the sun it orbits. This is the heaviest planet orbiting an ultracool dwarf star ever found. It is thirteen times larger than the Earth’s mass.

This discovery therefore also challenges existing models of the formation of solar and planetary systems.

Stars form from large clouds of gas and dust. After a star forms, gas and dust remain as disks of material that can eventually grow into planets. To find a planet like the one we see today around this ultracool dwarf star, the dust-to-mass and dust-to-gas ratios in the disk in its early days would have to be ten times higher than what has been observed.

The discovery was made using the US habitable zone planet finder. Although it is difficult to find planets orbiting stars like our Sun, they are easier to find around ultracool stars.

If the star is cooler, the planet must be closer to that star to gain enough heat to form liquid water. If it is close enough, it can be seen from Earth thanks to very subtle changes in the color of the spectrum or starlight as the planet passes in front of the star.

Read more about the research here: The planet was found to be too large in size relative to its parent star