Bhubaneswar: Astronomers recently have announced the discovery of the first known planet orbiting Barnard’s Star, the closest single star to our solar system
They have made a breakthrough in the search for distant worlds. They sighted four such rocky exoplanets orbiting Barnard’s Star, the closest solitary star to Earth at just under six light-years away.
This discovery, led by Ritvik Basant from the University of Chicago, not only validates a previously suspected planet but also reveals three entirely new worlds—all smaller than Earth.
The researchers have published their exciting findings in the The Astrophysical Journal letters on March 11, 2025.
WHAT IS BARNARD’S STAR?
Barnard’s Star is a dim red dwarf star of 10 billion year old (see the image aboce). It has long been a prime target for exoplanet hunters due to its proximity.
While Proxima Centauri is technically the nearest star to the Sun, it belongs to a multiple-star system.
In contrast, Barnard’s Star is the closest single star, making it an ideal laboratory for studying planetary systems around lone red dwarfs—the most common type of star in our galaxy, reports the journal.
Astronomers previously have confirmed one planet orbiting Barnard’s Star, which is smaller and less massive than Earth.
In November 2024, researchers reported the discovery of a planet orbiting Barnard’s Star with a period of 3.154 days. The data hinted at the presence of three other planets, but these candidates could not be confirmed then.
WHAT’S NEW?
The team observed Barnard’s Star from 2021 to 2023 with the M dwarf Advanced Radial velocity Observer Of Neighboring eXoplanets (MAROON-X). Over three years and 112 nights of observations using the MAROON-X instrument on the Gemini North telescope in Hawaii, scientists have uncovered four new worlds.
Now, a total of four known planets have been confirmed. And all are “mini-Earths,” which have only 19% to 34% of the mass of Earth.
RELEVANCE OF DISCOVERY?
After the four exo-planets discovered, the moot question popped up was: could any of these planets be habitable?
The researchers said, “none of the newly discovered planets lie within Barnard’s Star’s habitable zone, which spans orbital periods from 10 to 42 days. The current data also rule out the presence of habitable-zone planets with masses greater than 0.57 Earth mass, though smaller planets are still possible.”
These planets are too close to Barnard’s Star to support life for they experiencing scorching temperatures.
Their discovery only highlights just how many small, rocky planets might be out there.
Barnard now holds the record as the lightest exoplanet ever discovered using radial velocity, proving that even the tiniest worlds can be detected with today’s technology.
With this discovery, astronomers edge closer to answering one of the universe’s biggest questions: Just how common are Earth-like planets?
