Exciting Discovery: Two Earth-Sized Exoplanets Around Nearby Star HD 101581!

In a remarkable breakthrough, an international team of astronomers has unveiled the discovery of two Earth-sized exoplanets orbiting the nearby star HD 101581. This thrilling find was reported in a paper published on December 12 on the pre-print server arXiv and is set to reshape our understanding of planetary systems close to home.

NASA's Transiting Exoplanet Survey Satellite (TESS) has been a game-changer in the hunt for exoplanets, having identified over 7,300 candidate worlds since its launch in April 2018. Out of these, 589 have received confirmation. TESS's mission focuses on surveying around 200,000 of the brightest stars near our solar system in a quest to locate transiting exoplanets—those that pass in front of their stars from our perspective.

The latest findings were spearheaded by Michelle Kunimoto and her team at the Massachusetts Institute of Technology (MIT), who confirmed the planetary status of two TESS Objects of Interest (TOI) associated with HD 101581. The researchers found transit signals linked to the two newly identified exoplanets, which are both slightly smaller than Earth.

The inner planet, designated HD 101581 b, has a radius of approximately 0.956 Earth radii and a mass not exceeding 3.6 times that of Earth. It completes its orbit every 4.47 days, turning around its sun-like star from a mere distance of 0.046 astronomical units (AU), leading to an estimated equilibrium temperature of around 834 Kelvin (about 561 degrees Celsius).

The second planet, named HD 101581 c, has a radius of 0.99 Earth radii and could weigh up to 4.2 times more than our planet. It orbits its star in 6.21 days at a distance of approximately 0.057 AU, with an equilibrium temperature calculated at 747 K (around 474 degrees Celsius).

Further intriguing news emerged as the astronomers detected a possible signal indicative of a third planet, tentatively termed HD 101581 d. If confirmed, this planet would be about 0.98 Earth radii in size, possess a maximum mass of 3.6 Earth masses, and have an orbital period of roughly 7.87 days.

HD 101581 itself is a K dwarf star located about 41.7 light-years away from Earth. With a radius approximately 0.63 times that of our sun and a mass of about 0.74 solar masses, this star is nearly 7 billion years old and shines with a V-band magnitude of 7.77, making it one of the brightest known stars with multiple transiting planets under 1.5 Earth radii.

This groundbreaking discovery not only adds to the growing catalog of exoplanets but also fuels the debate about the potential habitability of these alien worlds. As astronomers continue their observations, we may soon learn more about the atmospheres and compositions of these intriguing planets. The hunt for neighboring life just became a lot more exciting!