By 2025, astronomers had cataloged a minimum of 14 stars located within 10 light-years from our Sun. Following this, Alpha Centauri system the nearest one after this is Barnard's Star , an isolated red dwarf approximately 6 light-years distant. Thanks to recent observations, we have discovered that Barnard's Star is encircled by four petite, terrestrial exoplanets.
However, it hasn't been an easy journey. Ever since its detection in 1916 by the American astronomer Edward Emerson Barnard, Barnard’s star has experienced multiple assertions of celestial bodies revolving around another object , tracing back to the 1960s. More recently, a A super-Earth was hypothesized in 2018. However, this finding was debunked in 2021.
Research released in August 2024 ultimately verified the existence of a planet around Barnard's Star , known as Barnard's Star b or simply Barnard b.
And now, three more planets have been verified in a study released on March 11 in The Astrophysical Journal Letters This brings the total number of planets up to four.
Watching wobbles
All these planets were discovered through the radial velocity technique, often referred to as the "wobble" method. This approach detects changes in the wavelengths of light coming from stars due to the gravitational pull exerted by orbiting planets causing a back-and-forth motion. Smaller planets still cause a noticeable wobble in their parent star when both revolve around their common center of mass. Astronomers utilize tools such as ESPRESSO at the European Southern Observatory’s Very Large Telescope in Chile—used for detecting Barnard b—and MAROON-X on the Gemini North telescope in Hawaii—which recently pinpointed three new exoplanets—to measure the alterations in stellar light frequencies as they move towards and then away from Earth. Analyzing this light pattern enables scientists not only to confirm planetary presence but also to ascertain characteristics like each world's dimensions.
The latest study, spearheaded by researchers from the University of Chicago, involved observing Barnard's Star 112 times with MAROON-X between 2021 and 2023. During this period, they noticed some possible signals; however, these were dismissed asMAROON-X was still undergoing calibration at that point. The scenario shifted in late 2024 when another group found Barnard’s Star b utilizing ESPRESSO. Inspired by this finding, the UChicago team reviewed their earlier observations again, which resulted in identifying three additional planets: Barnard's Star c, d, and e.
The Barnard's Star system
The exoplanet Barnard b, which was found earlier, is believed to be a rocky world with about one-third of Earth's mass and completes an orbit around its star every 3.15 Earth days.
Every recently discovered planet is a petite world, not exceeding roughly one-third of Earth's mass, completing an orbit around its parent star in under seven days.
Even though Barnard's Star is a petite and faint red dwarf slightly larger than Jupiter and considerably less luminous compared to our sun, the four planets all circle very near to their star. This proximity places them inside the inner edge of what we call the habitable zone—the area around a star where conditions might permit liquid water to exist on a planet’s surface. Consequently, because these worlds orbit so close to their star, the resulting temperatures are too elevated for liquid water to persist on their surfaces.
The four planets are equally vulnerable to the unpredictable nature of their star. Despite being fainter, red dwarfs such as Barnard’s Star exhibit far greater activity compared to bigger stars like our sun. Estimated to be at least 10 billion years old, Barnard’s Star shows relatively lower levels of activity when contrasted with many other red dwarfs; however, it occasionally experiences bursts of stellar action. These outbursts include notable events in 1998 and 2019, which led researchers to conclude that any planets circling this star might struggle to retain their atmospheres over long geologic periods.
Even though the chances of finding life here seem bleak, this revelation indicates that numerous additional planets probably remain undiscovered even in our immediate vicinity. Following the confirmation of the first exoplanet back in 1995, we've since identified approximately 6,000 more. The tally will most certainly keep climbing at an accelerating pace, carrying profound implications regarding humanity’s role in the cosmos.
The post Three newly discovered planets orbiting Barnard's Star have been identified. appeared first on MassimaMagazine .