TOI-3984 A b and TOI-5293 A b: Two Temperate Gas Giants Transiting Mid-M Dwarfs in Wide Binary Systems
Caleb I. Cañas, Shubham Kanodia, Jessica E. Libby-Roberts, Andrea S. J. Lin, Maria Schutte, Luke Powers, Sinclaire Jones, Andrew Monson, Songhu Wang, Guðmundur Stefánsson, William D. Cochran, Paul Robertson, Suvrath Mahadevan, Adam F. Kowalski, John P. Wisniewski, Brock A. Parker, Alexander Larsen, Franklin A. L. Chapman, Henry A. Kobulnicky, Arvind F. Gupta, Mark E. Everett, Bryan E. Penprase, Gregory R. Zeimann, Corey Beard, Chad F. Bender, Knicole D. Colón, Scott A. Diddams, Connor Fredrick, Samuel Halverson, Joe P. Ninan, Lawrence W. Ramsey, Arpita Roy, Christian Schwab
Abstract
Abstract We confirm the planetary nature of two gas giants discovered by TESS to transit M dwarfs with stellar companions at wide separations. TOI-3984 A ( J = 11.93) is an M4 dwarf hosting a short-period (4.353326 ± 0.000005 days) gas giant ( M p = 0.14 ± 0.03 M J and R p = 0.71 ± 0.02 R J ) with a wide-separation white dwarf companion. TOI-5293 A ( J = 12.47) is an M3 dwarf hosting a short-period (2.930289 ± 0.000004 days) gas giant ( M p = 0.54 ± 0.07 M J and R p = 1.06 ± 0.04 R J ) with a wide-separation M dwarf companion. We characterize both systems using a combination of ground- and space-based photometry, speckle imaging, and high-precision radial velocities from the Habitable-zone Planet Finder and NEID spectrographs. TOI-3984 A b ( T eq = 563 ± 15 K and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>TSM</mml:mi> <mml:mo>=</mml:mo> <mml:msubsup> <mml:mrow> <mml:mn>138</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>27</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>29</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> ) and TOI-5293 A b ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>T</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>eq</mml:mi> </mml:mrow> </mml:msub> <mml:mo>=</mml:mo> <mml:msubsup> <mml:mrow> <mml:mn>675</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>30</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>42</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> K and TSM = 92 ± 14) are two of the coolest gas giants among the population of hot Jupiter–sized gas planets orbiting M dwarfs and are favorable targets for atmospheric characterization of temperate gas giants and 3D obliquity measurements to probe system architecture and migration scenarios.