In a remarkable breakthrough, astronomers have unveiled a newly discovered Saturn-like exoplanet, TOI-5344 b, orbiting an M-dwarf star. This groundbreaking revelation comes as NASA's Transiting Exoplanet Survey Satellite (TESS) continues to amass an impressive catalog of alien worlds, with the findings published on October 31 in a paper available on the pre-print server arXiv.
TESS, launched in April 2018, has since identified nearly 6,900 candidate exoplanets, also known as TESS Objects of Interest (TOI). Among these candidates, 398 have been confirmed, marking a significant stride in our quest to uncover the mysteries of our cosmic neighborhood.
A team of dedicated astronomers, led by Te Han from the University of California, Irvine, has now added TOI-5344 b to the roster of confirmed exoplanets monitored by TESS. The telltale sign of this alien world was observed in the light curve of TOI-5344, an M-dwarf star located approximately 444 light years away from Earth. The team cemented the planetary identity of this celestial body through meticulous ground-based observations.
TOI-5344 b, Saturn's long-lost sibling, is nearly 10 times the size of Earth and an astonishing 135 times more massive, resulting in a density of about 0.8 grams per cubic centimeter. This awe-inspiring planet completes an orbit around its host star in a mere 3.8 days, at a distance of approximately 0.04 astronomical units (AU). The equilibrium temperature on TOI-5344 b is a scorching 679 Kelvin.
Researchers have classified TOI-5344 b as a Saturn-like exoplanet, with a comparable metal mass fraction to that of Saturn. It joins a select group of approximately 20 "GEMS" (giant exoplanets around M-dwarf stars) characterized by radii between 8 and 15 times that of Earth and a mass exceeding our planet's by at least 80 times.
Examining the host star, TOI-5344, reveals a star with a radius of about 0.56 times that of our Sun and a mass equivalent to 0.59 solar masses. This aged star, approximately 7.1 billion years old, boasts an effective temperature of 3,770 Kelvin and exhibits a metallicity level of 0.48 dex, making it one of the most metal-rich transiting GEMS hosts observed.
The discovery of TOI-5344 b and its host star TOI-5344 underscores the immense potential of TESS and the growing repository of exoplanet data it provides. This newfound knowledge offers hope for the discovery of more exoplanets akin to TOI-5344 b, shedding light on the formation and evolution of giant exoplanets orbiting M-dwarf stars.
"While GEMS remain elusive in the cosmos, TESS's remarkable capabilities have paved the way for several groundbreaking discoveries," the researchers conclude. As TESS continues its mission, we can look forward to unraveling the enigmatic tapestry of our universe, one exoplanet at a time.