Scientists have discovered a fascinating “super-Earth” just 20 light-years away. It’s the outermost of three planets orbiting the star HD 20794 and experiences extreme temperature shifts, alternating between intense heat and cold.
This planet completes an oval-shaped orbit around its star in 647 days, similar to how Mars circles the Sun. Its stretched path causes it to move dramatically closer to and farther from its star, leading to scorching heat at its nearest point, comparable to the conditions on Venus.
It experiences bitter cold at its farthest, nearly twice Earth’s distance from the Sun. These extremes occur roughly every 300 days, potentially shaping the planet’s history for billions of years.
The planet occasionally moves into its star’s “habitable zone,” where liquid water could potentially exist under the right conditions. This raises the possibility of it supporting life. However, its climate is highly unstable. When it orbits closest to the star, the heat pushes it out of the habitable zone. Conversely, when it’s farthest, the frigid temperatures also place it beyond the zone.
This bizarre exoplanet is the remnant core of a gas giant planet
Scientists speculate that this planet could have a rocky surface like Earth but with a mass six times greater, making it a much heftier cousin to our home world.
A group of astronomers, led by Nicola Nari, has officially identified this “super-Earth” after studying over two decades of data from HD 20794. They utilized advanced tools like HARPS and ESPRESSO, based in observatories in Chile, which track tiny wobbles in a star’s motion caused by the pull of orbiting planets.
However, their work was far from simple. Similar wobbles can also result from star-related activities like flares or surface spots. The team carefully analyzed the data to separate accurate planetary signals from these “false alarms.” Their thorough investigation showed that HD 20794 is a calm and stable star, making it easier to confirm the presence of this intriguing planet.
This unusual super-Earth has already intrigued scientists who are exploring the possibility of habitable planets. It’s a relatively short distance from Earth and its fascinating traits make it a strong contender for future studies by advanced telescopes like NASA’s planned Habitable Worlds Observatory (HWO). This observatory, expected to launch in the coming decades, will examine the atmospheres of planets around stars like our Sun, searching for life-indicating gases by breaking down starlight into detailed spectra.
The HD 20794 system, with its dramatic and eccentric super-Earth, could become a key focus in humanity’s ongoing effort to discover life beyond Earth. For now, it remains a compelling enigma, perched between extremes of potential habitability and challenging conditions.
Journal Reference:
- Nicola Nari, Michael Cretignier et al. 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 and Astrophysics. DOI: 10.1051/0004-6361/202451769
Source: Tech Explorist
