Astronomers find two giant exoplanets HD 114082

Astronomers led by the University of La Laguna and the Institute of Astrophysics of the Canary Islands said on May 18 that they had identified two giant exoplanets orbiting the young star HD 114082. The finding was published in *Astrophysical Journal Letters* and described the pair as the longest-period young transiting exoplanets known. The system sits inside a debris disk, giving researchers a case to study how giant planets form and settle into orbit around a very young star. The observations combined data from NASA’s TESS mission, ESA’s CHEOPS satellite and several ground-based telescopes. ### Why are astronomers paying attention to HD 114082? HD 114082 is about 15 million years old, far younger than the Sun’s roughly 4.6 billion years, according to the research team and earlier studies of the system. The star is also more massive, hotter and more luminous than the Sun, and it spins about 15 times faster, the team said. Those properties make it a useful target for studying planets early in their evolution, while they are still inflated and interacting with leftover material from their birth environment. (abc.com.py) A 2023 study had already identified one transiting giant planet around HD 114082. That earlier work estimated planet b at about 8 Jupiter masses, with a radius close to Jupiter’s and an orbit of about 0.51 astronomical units, or roughly half the Earth-Sun distance. The new paper adds a second transiting planet and recasts the system as a two-planet benchmark inside a debris disk. (abc.com.py) ### What exactly did the team find around the star? The new paper identified two large-radius planets orbiting the F-type star HD 114082. Carlos del Burgo Díaz, the study’s lead author, said the pair stands out among the youngest known transiting planets because both take comparatively long to orbit their star. The inner planet, HD 114082 b, is about Jupiter-sized and orbits about 20% closer to its star than Earth does to the Sun, the team said. (arxiv.org) The outer planet, HD 114082 c, is the headline result. The team said it orbits at roughly 1 astronomical unit, about the Earth-Sun distance, and has a radius 36% larger than Jupiter’s. The paper cited by Oxford’s repository gives the second planet’s radius as 1.29 ± 0.05 Jupiter radii, while the press material rounded that to about 36% larger than Jupiter. (abc.com.py) ### Why does the outer planet look so unusual? The outer planet’s average density is more than 7.5 times lower than water, the researchers said. Spanish media reports based on the team’s release said that would make it buoyant in water, a shorthand for how inflated and low-density the planet appears. The same report said the measured mass of the outer planet is less than 24% of Jupiter’s mass, or about 4.4 Neptune masses. (abc.com.py) Alejandro Suárez Mascareño, a co-author, said the two planets move on nearly circular orbits in the same plane and may be in or near resonance, meaning their orbital periods could be linked by a simple ratio. That geometry can help astronomers test models of how giant planets migrate and interact after formation. (elmundo.es) ### How did astronomers detect both planets? TESS first recorded a transit from the inner planet, and additional dips in brightness were tracked with other instruments, according to the paper and the IAC summary. The broader observing campaign used TESS and CHEOPS in space, plus the Next-Generation Transit Survey in Chile, ASTEP+ in Antarctica and Las Cumbres Observatory on the ground. Those light curves let researchers measure repeated transits of the inner planet and identify evidence for the outer one. (abc.com.py) A separate 2025 debris-disk study also reported a second transiting giant planet in the HD 114082 system, with a radius of 1.29 Jupiter radii and an orbital distance of about 1 astronomical unit. That independent appearance in the literature aligns with the parameters reported in the new exoplanet paper. ### What comes next for this system? Carlos del Burgo said the next step is to catch a second transit of the outer planet so astronomers can pin down its orbital period more precisely. (abc.com.py) After that, the team said, measuring the timing of multiple transits from both planets could refine their masses and potentially reveal additional bodies in the system. The University of La Laguna said future observations could also involve facilities such as the James Webb Space Telescope. (arxiv.org)