Researchers from the University of California – Irvine have identified a new super-Earth located in the habitable zone of an M-dwarf star, approximately 18 light-years from Earth. This discovery positions the planet, designated GJ 251 c, as a key target in the ongoing search for extraterrestrial life, particularly due to its potential to harbor liquid water.
The habitable zone is a crucial region around a star where conditions may be suitable for life as we know it, primarily allowing for the existence of liquid water. Given that liquid water is essential for all known forms of life, GJ 251 c’s proximity and characteristics make it an exciting candidate for further study.
Characteristics of GJ 251 c
GJ 251 c is categorized as a super-Earth, meaning it has a mass several times greater than that of Earth while maintaining a rocky structure. Co-author Paul Robertson, an associate professor of physics and astronomy at UC Irvine, highlighted the significance of the planet’s location. “What makes this especially valuable is that its host star is close by, at just about 18 light-years away. Cosmically speaking, it’s practically next door,” he stated.
The planet orbits an M-dwarf star, which is the most common type of star in the Milky Way. While M-dwarfs are known for their age and varying activity, including starspots and flares, the challenges they present in detecting orbiting planets did not deter the researchers. Despite these stellar activities mimicking the signals astronomers seek, the proximity of GJ 251 c offers a promising opportunity for direct imaging.
Advanced Detection Techniques
The research team utilized data from advanced instruments, the Habitable-zone Planet Finder and NEID, to detect the planet’s presence. These precision tools measure the subtle gravitational influences a planet exerts on its star, causing periodic shifts in the star’s light, known as radial velocity signatures.
The Habitable-zone Planet Finder is especially adept at mitigating the effects of M-dwarf stellar activity by observing in the infrared spectrum, where disruptive signals from the star are less pronounced. The team’s efforts have confirmed GJ 251 c as a candidate exoplanet, bolstering the necessity for direct imaging to validate its properties.
Lead author Corey Beard, a data scientist at Design West Technologies and former graduate student in Robertson’s group, expressed optimism regarding future observations. “TMT will be the only telescope with sufficient resolution to image exoplanets like this one. It’s just not possible with smaller telescopes,” he noted, referring to the Thirty Meter Telescope, which is currently in development.
Future Prospects
While the discovery of GJ 251 c represents a significant advancement in exoplanet research, the team acknowledges that further verification through imaging is essential. The project received backing from multiple sources, including NSF grant AST-2108493 and NASA/NSF funding for the NN-EXPLORE program.
Beard and Robertson hope their findings will inspire the exoplanet research community to explore GJ 251 c further, particularly as new ground-based observatories, such as the Thirty Meter Telescope, approach operational status. Collaborators on this research included experts from institutions such as Pennsylvania State University and the University of Colorado, Boulder.
Through this discovery, scientists take a step closer to understanding the potential for life beyond Earth, prompting further investigation into this intriguing planetary candidate.