Kepler-139f: Scientists Just Discovered the Super-Earth Exoplanet, Which is 36 Times Earth's Mass; All You Need To Know

Introduction

In a groundbreaking discovery, scientists from NASA have uncovered a hidden exoplanet in the Kepler-139 star system. This exoplanet is named Kepler-139f. This newly discovered exoplanet is a massive “super-Earth,” significantly larger than Earth, but it is smaller than other gas giant planets like Neptune. For millions of years, these exoplanets existed, and despite being enormous and having a strong gravitational pull, it is a wonder that, under NASA scientists, they were hidden till 2025. But due to the Kepler space telescope of NASA, it has been discovered, which was published in the Astrophysical Journal Letters on May 02, 2025.

Source: NASA

Kepler-139 f: The Hidden Super-Earth Revealed

Kepler-139f is a gas-rich exoplanet estimated to be 36 times the mass of Earth and roughly twice as heavy as Neptune. It takes about 355 Earth days to complete one orbit around its parent star, a G-type star similar to our Sun.

So why was this Kepler-139 f, the SuperEarth, unnoticed for so long? 

Kepler-139 f, which is also a Super-Earth, was unnoticed for so long due to its orbital alignment. NASA’s Kepler Space Telescope, which operated for nearly a decade, discovered thousands of exoplanets using the transit method—detecting tiny dips in a star’s brightness as planets passed in front of it. However, Kepler’s view was limited to a narrow field of vision. Planets orbiting outside this “line of sight” remained invisible unless they affected nearby bodies in measurable ways.

How was Kepler-139 f, the Super-Earth, discovered?

Kepler-139 was already known to host three rocky super-Earths, all of which transited their star. Later, a fourth gas giant, Kepler-139e, was discovered using radial velocity (RV)—a technique that tracks the tiny wobbles a planet causes in its star’s motion.

But gaps in the orbits of these known planets hinted at the presence of something more. By analysing Transit Timing Variations (TTVs)—subtle changes in when planets cross their star due to gravitational nudges from other unseen bodies—astronomers found strong evidence pointing to Kepler-139f.

As Caleb Lammers, a researcher from Princeton University and co-author of the study, explained, “It’s not just about spotting planets that don’t transit. It’s about identifying when and where they exert their influence.”

What is a Super-Earth?

A Super-Earth refers to an exoplanet that is larger than Earth but smaller than Neptune. It generally weighs up to twice the Earth's weight and usually 10 times the Earth’s mass. However, the term only describes a planet’s size, not its composition or habitability. Super-Earths can be made of rock like Earth, ice like snowball planets, or gas-rich like Neptunes. Super-Earths are just discovered, taking the reference of Earth’s size and mass, but their original structure and their true nature remain uncertain.

Scientists are now observing a Super-Earth in our solar system, making their study through exoplanet research crucial for understanding planetary diversity in the galaxy.

Conclusion

The discovery of Kepler-139f marks another exploration of the exoplanet. Although this super-earth was invisible for so many years, being 36 times Earth's mass and gravitational pull, scientists just discovered this exoplanet by using the Kepler Space Telescope and analysing the  Transit Timing Variations (TTVs) of Kepler-139f. As our tools grow more sophisticated, we are likely to uncover even more of these hidden worlds—and possibly, one day, even a planet like our own.