New planet nearby

The third planet discovered orbiting Centaurus at close range is the lightest planet discovered using radial velocity technology.

A team of astronomers welcomed a new exoplanet near our celestial body and found evidence of a third planet orbiting Centaurus, the closest star to the solar system near the constellation Centaurus.

Researchers have found in Astronomy and Astrophysics that there are many new and wonderful things waiting to be discovered in our night sky.

Lead author João Faria, a researcher and lead author at the Espaso Institute for Astronomy and Citizenship in Portugal, said: "This discovery suggests that our nearest stellar neighbour seems to be filled with interesting new worlds for further research and future exploration. ”

The newly discovered planet, dubbed Proxima d, is so lightweight and fast that it weighs only a quarter of Earth's mass and takes just five days to complete its orbit around Proxima Centauri. Its orbit is about 4 million kilometers away from the star, and Mercury is less than a tenth of the Sun's, making it too close to the habitable zone on Earth's surface that can hold liquid water.

The planet has two known celestial siblings and also orbits in close proximity orbit around the constellation Centauri: Proximity B, a planet of Earth-sized mass that orbits the star every 11 days and is located in a habitable zone; and Candidate Planet C, which is in a longer five-year orbit.

The planet is so small that astronomers can find it. This was discovered using radial velocity techniques, which capture tiny jitters in the motion of stars produced by the gravitational pull of orbiting planets. Because of its small size, proxima d's gravity only causes Proxima Centaurus to move back and forth at about 40 centimeters per second — an unusually fine motion detected within a few light years.

In an effort to observe the larger Proxima b, the first clues to the existence of proxima d were detected. A few years ago, instruments on the (ESO) 3.6-meter telescope initially identified the Earth-like planet, but its existence was not confirmed until 2020 when scientists used a new instrument, ESPRESSO, to study the Proxima system more closely.

In the process of verifying proxima b's existence, astronomers discovered an unusually weak signal that could correspond to an object with a five-day orbit — or just a wave of the star itself.

After several rounds of follow-up observations with ESPRESSO, the team was pleased to confirm that the signal was a new planet.

Faria said: "I am excited about the challenge of detecting such a small signal and discovering exoplanets so close to Earth by doing so. ”

Proxima d created the lightest exoplanet ever measured using radial velocity technology, surpassing a recently discovered planet.

Pedro Figueira, ESO instrument scientist in Chile, said: "This achievement is extremely important. He explained that Proxima d's detection shows that astronomy is increasingly capable of capturing the universe in detail.

"This suggests that radial velocity technology has the potential to reveal the number of light planets like ours, which are expected to be the richest in our galaxy and may house life as we know it."

Faria is equally excited about the new discoveries awaiting.

"This result clearly demonstrates ESPRESSO's capabilities and makes me wonder what it can find in the future," he said. ”

ESO's Very Large Telescope (ELT), which is currently under construction in the Atacama Desert, will complement ESPRESSO's exploration of other worlds, which is essential for discovering and studying more planets around nearby stars.