According to the latest research by an international astronomy team composed of Queen's University and other institutions, astronomers have successfully discovered an extremely rare exoplanet - NGTS-38 b. This giant planet called "Super Jupiter" is about 4.5 times as massive as Jupiter and about 8% wider than Jupiter. Its most significant feature is that it takes 180 days (about half a year) to orbit its host star. Among the exoplanets currently detected through the "transit method", its revolution period ranks among the best.
Clues about the planet date back to Christmas 2020, when NASA's Transiting Exoplanet Survey Satellite (TESS) captured a single faint dip in the star's brightness caused by the planet's obstruction, known as a "transit." Subsequently, a research team led by Professors Toby Rodel and Christopher Watson, doctoral students at Queen's University, used the Next Generation Transit Survey (NGTS) telescope in Chile to continuously monitor the star for more than 200 nights, and finally successfully captured the end of the second transit. The research team further analyzed the splitting and light wave changes of the star's spectrum, and measured the tiny gravitational pull exerted by the planet on the star. Finally, combined with data from multiple parties, they confirmed the existence of this planet with an orbital period of 180 days.
Normally, planets in long-period orbits are extremely difficult to detect because they pass in front of their star so infrequently. Research shows that the orbit of NGTS-38 b is not a perfect circle, but a mild ellipse. At periapsis of its orbit, its distance from the star is only slightly farther than the distance from Mercury to the sun; while at aphelion, its distance is close to the distance from the earth to the sun. Because its host star is larger and hotter than the sun, the overall temperature of this planet is higher than that of the Earth. It is a relatively low-temperature "warm super Jupiter" among similar giant planets.
Astronomers pointed out that the huge mass of NGTS-38 b gives it an extremely strong gravitational pull, and because it is far enough away from the host star, it has the potential conditions to capture and maintain satellites or planetary rings, which provides a very valuable target for future exploration of exoplanets outside the solar system. In addition, pushing the detection limit of exoplanets to longer periods is also a key technology accumulation for the future search for habitable planets similar to Earth.
This result has been officially published in Monthly Notices of the Royal Astronomical Society. At the same time, another independent research team led by Felipe Rojas and Dr. Rafael Brahm from the Adolfo Ibáñez University in Chile also identified this planetary system and published its research results on arXiv. Scientists agree that such rare planets that retain "fingerprints" of their early formation will provide key evidence for revealing the origin and evolution mechanisms of giant planets.