A new super-earth in the cosmic neighborhood: Ross 318 b and the search for life

• An international team confirmed the existence of Ross 318 b, a super-Earth at least six times more massive than Earth, orbiting the red dwarf star Ross 318 just 28 light-years away within its conservative habitable zone.
• The planet was discovered by re-analyzing 15 years of radial velocity data from CARMENES and Keck Observatory, combined with TESS photometry, to separate the planet’s signal from the star’s strong magnetic activity.
• Ross 318 b orbits its cool star every 39.63 days at a distance of 0.16 AU, has an estimated radius of 1.74 Earth radii and an equilibrium temperature of -36°C, which could support liquid water with a sufficient atmosphere.
• Though likely tidally locked, the planet’s substantial mass suggests a thick atmosphere that could redistribute heat, making it a prime target for atmospheric study by the James Webb Space Telescope to detect water or organic molecules.
• The lead investigator is from an amateur astronomy association, highlighting how independent researchers using publicly available data can make significant exoplanet discoveries, challenging the notion that only large institutions can find habitable worlds.

In a discovery that underscores the growing potential for finding habitable worlds in our cosmic backyard, an international team of astronomers has confirmed the existence of a super-Earth orbiting the nearby red dwarf star Ross 318. Located just 28 light-years from Earth, this newly identified exoplanet, designated Ross 318 b, is at least six times more massive than our home planet and sits within its star’s conservative habitable zone.

The finding, published May 11 on the arXiv preprint server, was made possible by a meticulous re-analysis of 15 years of spectroscopic data and advanced space-based observations.

The stellar neighbor: Ross 318

Ross 318, also cataloged as Gliese 48 or TIC 379084450, is a red dwarf star of spectral type M3.5V. Red dwarfs make up 75% of Milky Way stars, making them prime targets in the search for habitable worlds. Their dimness allows easier detection of small planets and their longevity means stable conditions could persist for billions of years. With an effective temperature of approximately 3,450 Kelvin—significantly cooler than the Sun’s 5,778 Kelvin—Ross 318 presents both opportunity and obstacle.

The star exhibits strong magnetic activity, a common trait among such cool stars. Magnetic activity, including starspots and flares, creates noise in data that often obscures the subtle gravitational tugs of orbiting planets. For years, this has posed a major challenge for exoplanet searches around M-dwarfs, leaving many potential worlds hidden in plain sight.

How the planet was found

A team led by Giuseppe Conzo of the amateur astronomy association Gruppo Astrofili Palidoro in Italy, in collaboration with Brazilian researchers, realized that previous efforts to detect planets around Ross 318 had been hampered by the star’s magnetic variability. Rather than accept this limitation, they conducted a systematic re-analysis of radial velocity data from the CARMENES spectrograph and decade-long observations from the High Resolution Echelle Spectrometer at the Keck Observatory. These terrestrial instruments were complemented by space-based photometry from NASA’s Transiting Exoplanet Survey Satellite. The integration of these three data sets over a 15-year baseline allowed the team to separate genuine planetary signals from stellar noise. This approach mirrors the kind of independent, cross-checking methodology that often reveals truths overlooked by conventional shortcuts.

The analysis revealed a planet orbiting Ross 318 every 39.63 days. With a minimum mass of 6.21 Earth masses and a predicted radius of about 1.74 Earth radii, Ross 318 b qualifies as a super-Earth—a class of planet larger than Earth but smaller than Uranus or Neptune. Its orbital distance is roughly 0.16 astronomical units from its host star, or about 16 percent of the distance between Earth and the Sun. Because the star is much cooler than the Sun, this close orbit places the planet within the conservative habitable zone. The equilibrium temperature of Ross 318 b is estimated at 237 Kelvin, or about minus 36 degrees Celsius. While this is cold by Earth standards, it is warm enough to allow liquid water to exist if the planet has a sufficiently thick atmosphere.

Intriguingly, gravitational anomalies suggest another planet may lurk in the system, possibly in a cooler, more habitable zone. This possibility reinforces why red dwarfs matter: their prevalence and stability make them ideal laboratories for understanding planetary system formation and habitability.

Atmosphere and habitability potential

The planet is likely tidally locked, meaning one side perpetually faces its star while the other remains in eternal darkness. However, researchers note that Ross 318 b’s minimum mass suggests it may possess a substantial atmosphere. Such an atmosphere could efficiently redistribute heat from the scorching day-side to the frigid night-side, potentially moderating temperatures across the globe. This characteristic places Ross 318 b in the conservative habitable zone—a region where conditions might allow liquid water to exist on the surface, given the right atmospheric pressure and composition.

The discovery makes it one of the most interesting temperate super-Earths identified so far for future atmospheric characterization, particularly using transmission spectroscopy with the James Webb Space Telescope.

Historical context and the technical breakthrough

Over the past three decades, advances in precision spectroscopy and space telescopes have shifted the focus to smaller, rockier worlds. The discovery of Ross 318 b matters today because it demonstrates that even highly active, magnetically volatile red dwarfs—previously considered too challenging for planet detection—can harbor potentially habitable super-Earths.

By combining 15 years of radial velocity measurements from CARMENES and HIRES with photometric data from TESS, the astronomers effectively mitigated the confusion caused by starspots and magnetic cycles. This synergy between multi-instrumental spectroscopy and high-precision photometry resolved ambiguities that had previously masked the planetary signal. The researchers describe this as an emblematic example of how such integrated analysis can advance radial velocity techniques for active M-dwarfs.

Implications for the search for life and independent research

The discovery of a temperate super-Earth around a nearby red dwarf reinforces the idea that habitable planets may be far more common than previously assumed. While the conservative habitable zone is defined by the potential for liquid water, actual habitability depends on many factors, including atmospheric composition, geological activity and the presence of a magnetic field. Ross 318 b’s substantial mass suggests it could retain a thick envelope of gases, protecting any potential surface from the star’s magnetic outbursts.

“A red dwarf is a small, cool star with low luminosity that is the most common type in the universe,” said BrightU.AI’s Enoch. “These stars have relatively low temperatures and are essential for understanding stellar evolution, as well as offering valuable insights into planetary formation. One such star, K2-155, which is located about 200 light-years from Earth, hosts three super-Earths.”

Conzo, the lead investigator on this project, comes from an amateur astronomy association. The integration of publicly available data from TESS, CARMENES and HIRES demonstrates that groundbreaking discoveries are not limited to well-funded government agencies. For those committed to human liberty, independent research and the pursuit of truth, Ross 318 b is a reminder that the most important discoveries often come from looking where others said it was impossible to see.

Watch and discover a report on astronomers catching something strange in the sky.

This video is from the Planet Zedta channel on Brighteon.com.

Sources include:

Phys.org

BrightU.ai

Brighteon.com