The HD 191939 Exoplanet System is Well Aligned and Flat

We report the sky-projected spin–orbit angle λ for HD 191939 b, the innermost planet in a six-planet system, using Keck/KPF to detect the Rossiter–McLaughlin (RM) effect. Planet b is a sub-Neptune with radius 3.4 ± 0.8 R _⊕ and mass 10.0 ± 0.7 M _⊕ with an RM amplitude <1 m s ^−1 . We find the pl...

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Bibliographic Details
Published in:The Astronomical Journal
Main Authors: Jack Lubin, Erik A. Petigura, Judah Van Zandt, Corey Beard, Fei Dai, Samuel Halverson, Rae Holcomb, Andrew W. Howard, Howard Isaacson, Jacob Luhn, Paul Robertson, Ryan A. Rubenzahl, Guđmundur Stefánsson, Joshua N. Winn, Max Brodheim, William Deich, Grant M. Hill, Steven R. Gibson, Bradford Holden, Aaron Householder, Russ R. Laher, Kyle Lanclos, Joel Payne, Arpita Roy, Roger Smith, Abby P. Shaum, Christian Schwab, Josh Walawender
Format: Article
Language:English
Published: IOP Publishing 2024-01-01
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Online Access:https://doi.org/10.3847/1538-3881/ad79ed