At a Glance
- Researchers confirmed the existence of HD 20794 d, a super-Earth six times the mass of Earth, located 20 light-years away in the habitable zone.
- The discovery was based on two decades of data from HARPS and ESPRESSO spectrographs, which detected tiny shifts in light caused by the planet’s gravitational pull.
- Unlike most planets, HD 20794 d follows an elliptical orbit, moving between the inner and outer edges of the habitable zone, making its potential for life uncertain.
- Scientists plan to analyze the planet’s atmosphere using next-generation telescopes, such as the Extremely Large Telescope and the Habitable Worlds Observatory.
- HD 20794 d’s location and orbital characteristics make it a prime target for future space missions, which seek to understand conditions that might support extraterrestrial life.
An international team of researchers has confirmed the discovery of a new exoplanet called HD 20794 d, located just 20 light-years away from Earth. This super-Earth, which has a mass six times that of our planet, orbits a sun-like star within the habitable zone where liquid water could exist. This discovery, published in Astronomy & Astrophysics and building on data collected over two decades, offers a glimpse into the future of studying Earth-like exoplanets that may have suitable conditions for life.
The discovery was first flagged in 2022 by Dr. Michael Cretignier from Oxford University. While studying data from the HARPS spectrograph, which records light from distant stars, he noticed unusual periodic shifts that could be caused by a planet’s gravitational pull. To confirm the findings, an international team used over 20 years of data from HARPS and its successor, ESPRESSO, advanced instruments that can detect tiny variations in light. After meticulous analysis, the team confirmed that the signal was from a planet.
HD 20794 d’s orbit, however, is not circular like that of most planets. Instead, it follows an elliptical path, meaning the planet’s distance from its star changes throughout the year. This creates a unique situation where the planet alternates between the inner and outer edges of the habitable zone. While this makes it uncertain whether life could exist on the planet, its proximity to Earth and its location within the habitable zone make it a valuable target for future space missions aimed at studying Earth-like planets.
Scientists are eager to study this planet further, especially as next-generation telescopes like the Extremely Large Telescope and the Habitable Worlds Observatory are designed to detect signs of life in the atmospheres of exoplanets. Dr. Cretignier and his team are particularly excited about the potential for future missions to investigate HD 20794 d and other similar planets, as their unique orbits and location in the habitable zone provide an exciting opportunity for understanding more about the conditions that might support life beyond our solar system.
References
- University of Oxford. (2025, February 8). Researchers confirm an exoplanet potentially capable of sustaining life. Phys.Org; University of Oxford. https://phys.org/news/2025-02-exoplanet-potentially-capable-sustaining-life.html
- Nari, N., Dumusque, X., Hara, N. C., Suárez Mascareño, A., Cretignier, M., González Hernández, J. I., Stefanov, A. K., Passegger, V. M., Rebolo, R., Pepe, F., Santos, N. C., Cristiani, S., Faria, J. P., Figueira, P., Sozzetti, A., Zapatero Osorio, M. R., Adibekyan, V., Alibert, Y., Allende Prieto, C., … Venturini, J. (2025). Revisiting the multi-planetary system of the nearby star HD 20794: Confirmation of a low-mass planet in the habitable zone of a nearby G-dwarf. Astronomy & Astrophysics, 693, A297. https://doi.org/10.1051/0004-6361/202451769
