2024/12/12 by Michelle Kunimoto, Kunimoto, Michelle, Zifan Lin +89 · 1 voice · 1 citation
Physics and Astronomy · #Earth and Planetary Astrophysics (astro-ph.EP) #FOS: Physical sciences #astro-ph.EP
paper · pdf · doi:10.48550/arxiv.2412.08863
We report the validation of multiple planets transiting the nearby (d = 12.8 pc) K5V dwarf HD 101581 (GJ 435, TOI-6276, TIC 397362481). The system consists of at least two Earth-size planets whose orbits are near a mutual 4:3 mean-motion resonance, HD 101581 b (Rp = 0.956-0.061+0.063~R⊕, P = 4.47 days) and HD 101581 c (Rp = 0.990-0.070+0.070~R⊕, P = 6.21 days). Both planets were discovered in Sectors 63 and 64 TESS observations and statistically validated with supporting ground-based follow-up. We also identify a signal that probably originates from a third transiting planet, TOI-6276.03 (Rp = 0.982-0.098+0.114~R⊕, P = 7.87 days). These planets are remarkably uniform in size and their orbits are evenly spaced, representing a prime example of the "peas-in-a-pod" architecture seen in other compact multi-planet systems. At V = 7.77, HD 101581 is the brightest star known to host multiple transiting planets smaller than 1.5~R⊕. HD 101581 is a promising system for atmospheric characterization and comparative planetology of small planets.