Astronomers Discover Unique Exoplanet Orbiting Twin Stars

A team of astronomers has made a remarkable discovery, identifying an exoplanet that orbits two stars, reminiscent of the iconic twin suns from the “Star Wars” universe. The research, published in the journal Astronomy & Astrophysics, reveals that the planet, named HD 143811 AB b, is located approximately 446 light-years from Earth in a binary star system.

This newly observed exoplanet is a gas giant that orbits its twin stars at a distance closer than any previously documented binary star system exoplanet. Notably, HD 143811 AB b is situated about six times closer to its stars than any other known exoplanet in a similar system, providing a unique opportunity for researchers to study the planet’s trajectory as well as the movement of its host stars.

Significance of the Discovery

According to Jason Wang, an exoplanet imaging expert at Northwestern University, “Of the 6,000 exoplanets that we know of, only a very small fraction of them orbit binaries.” He emphasized that the ability to image both the planet and its binary stars simultaneously offers significant insights into their interactions. The planet takes approximately 300 years to complete one orbit around its stars, while the binary stars themselves rotate around each other every 18 days.

Despite being closer to its suns than other exoplanets, HD 143811 AB b remains about 80 times farther from its stars than Earth is from the Sun. The planet is also substantial in size, measuring around six times larger than Jupiter, which adds to its significance in astronomical studies.

This discovery is not entirely new; HD 143811 AB b was identified through archival data collected by the Gemini South telescope and its Gemini Planet Imager instrument, dating back roughly a decade. Wang and his colleagues revisited this data, initially gathered between 2016 and 2019, and cross-referenced it with information from the W.M. Keck Observatory.

Wang expressed surprise at finding a new planet, stating, “I didn’t think we’d find any new planets, but I thought we should do our due diligence and check carefully anyway.” Upon analyzing the data, they detected a faint dot that appeared to follow the trajectory of one of the stars, leading to further investigation.

Future Research and Implications

The team concluded that the entity was indeed a planet, a finding corroborated independently by researchers from the University of Exeter in the UK. Among the fascinating characteristics of HD 143811 AB b is its temperature, which reaches approximately 1,416°F—almost twice as hot as Venus. The planet is also relatively young, at around 13 million years old in cosmic terms, especially when considering the Earth’s age of 4.6 billion years.

The exact formation processes of HD 143811 AB b around its twin stars remain unclear. Wang noted, “Exactly how it works is still uncertain. Because we have only detected a few dozen planets like this, we don’t have enough data yet to put the picture together.”

As astronomers continue to track the orbits of HD 143811 AB b and its stars, they hope to uncover more about the interactions between binary stars and their accompanying planets. This ongoing research may shed light on the dynamics of such planetary systems and enhance our understanding of the universe.