Astronomers have confirmed the existence of four rocky planets orbiting Barnard’s Star, the closest single star to our solar system. Situated just six light-years away, Barnard’s Star has long been a source of fascination—and frustration—due to numerous false planet detections in the past.
However, this newly confirmed planetary family marks a triumph of high-precision technology and observational skill.
Finding small planets around distant stars is no easy feat. These planets, ranging from about a fifth to a third of Earth’s mass, exert only the faintest gravitational tug on their host star, creating tiny “wobbles” in its light.
Astronomers use the radial velocity method to detect these wobbles—measuring shifts in the star’s light spectrum caused by the planet’s pull. But the challenge is immense.
For Barnard’s Star, the signals produced by its planets are as subtle as 0.2 to 0.5 meters per second, while the star’s natural “noise” from quakes and jitters is nearly 10 times larger.
To overcome this hurdle, researchers developed advanced mathematical models to filter out the star’s activity and isolate the whispers of planetary motion. The breakthrough technology, MAROON-X—an extreme-precision radial velocity instrument mounted on the Gemini Telescope in Hawaii—played a key role in confirming the discovery. The findings also built upon earlier data from ESPRESSO, another high-precision instrument on Chile’s Very Large Telescope.
The planets, designated as b, c, d, and e, are packed tightly around their red-dwarf host star, completing their orbits in two to seven days. Their close proximity means they are far too hot to support life as we know it.
However, their detection is a significant step forward in the search for potentially habitable worlds. Small, rocky planets are thought to be ideal for finding signs of life, but they remain among the hardest to detect and analyze.
First identified in 1916 by astrophotographer Edward Emerson Barnard, Barnard’s Star has long intrigued scientists. This latest discovery sheds light on the tiny worlds circling it and raises hopes for uncovering more Earth-like planets in the future.
The discovery was officially added to NASA’s Exoplanet Archive on March 13, 2025. Though these planets may not host life, their discovery demonstrates the growing power of precision astronomy and its potential to reveal new, habitable worlds in the cosmos.
Journal Reference:
- Ritvik Basant, Rafael Luque, Jacob L. Bean, Andreas Seifahrt, Madison Brady, Lily L. Zhao, Nina Brown, Tanya Das, Julian Stürmer, David Kasper. Four Sub-Earth Planets Orbiting Barnard’s Star from MAROON-X and ESPRESSO. The Astrophysical Journal Letters. DOI 10.3847/2041-8213/adb8d5
Source: Tech Explorist
