Two Earth-size Planets and an Earth-size Candidate Transiting the nearby Star HD 101581*
M. Kunimoto, Z. Lin, S. Millholland, A. Venner, N. R. Hinkel, A. Shporer, A. Vanderburg, J. Bailey, R. Brahm, J. A. Burt, R. P. Butler, B. Carter, D. R. Ciardi, K. A. Collins, K. I. Collins, K. D. Colón, J. D. Crane, T. Daylan, M. R. Díaz, J. P. Doty, F. Feng, E. W. Guenther, J. Horner, S. B. Howell, J. Janik, H. R. A. Jones, P. Kabáth, S. Kanodia, C. Littlefield, H. P. Osborn, S. O’Toole, M. Paegert, P. Pintr, R. P. Schwarz, S. Shectman, G. Srdoc, K. G. Stassun, J. K. Teske, J. D. Twicken, L. Vanzi, S. X. Wang, R. A. Wittenmyer, J. M. Jenkins, G. R. Ricker, S. Seager & J. Winn
Published in The Astronomical Journal, 2024
We report the validation of multiple planets transiting the nearby (\(d = 12.8\) pc) K5V dwarf HD 101581 (GJ 435, TOI-6276, TIC 397362481). This system consists of at least two Earth-size planets whose orbits are near a mutual 4:3 mean-motion resonance, HD 101581 b (\(P = 4.47\) days) and HD 101581c (\(P = 6.21\) 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 (\(P = 7.87\) 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 multiplanet systems. At \(V = 7.77\), HD 101581 is the brightest star known to host multiple transiting planets smaller than \(1.5\,R_\oplus\). HD 101581 is a promising system for atmospheric characterization and comparative planetology of small planets.
Recommended citation: Kunimoto, Michelle and Lin, Zifan and Millholland, Sarah et al. (2024). "Two Earth-size Planets and an Earth-size Candidate Transiting the nearby Star HD 101581*." The Astronomical Journal.
Link to Paper