TOI-1859b: A 64 Day Warm Jupiter on an Eccentric and Misaligned Orbit

Dong, Jiayin; Wang, Songhu; Rice, Malena; Zhou, George; Huang, Chelsea X.; Dawson, Rebekah, I; Stefansson, Gudmundur K.; Halverson, Samuel; Kanodia, Shubham; Mahadevan, Suvrath; McElwain, Michael W.; Alvarado-Montes, Jaime A.; Ninan, Joe P.; Robertson, Paul; Roy, Arpita; Schwab, Christian; Logsdon, Sarah E.; Terrien, Ryan C.; Collins, Karen A.; Srdoc, Gregor; Sefako, Ramotholo; Laloum, Didier; Latham, David W.; Bieryla, Allyson; Dalba, Paul A.; Dragomir, Diana; Villanueva, Steven, Jr.; Howell, Steve B.; Ricker, George R.; Seager, S.; Winn, Joshua N.; Jenkins, Jon M.; Shporer, Avi; Rapetti, David
2023
ASTROPHYSICAL JOURNAL LETTERS
DOI
10.3847/2041-8213/acd93d
Warm Jupiters are close-in giant planets with relatively large planet-star separations (i.e., 10 < a/R* < 100). Given their weak tidal interactions with their host stars, measurements of stellar obliquity may be used to probe the initial obliquity distribution and dynamical history for close-in gas giants. Using spectroscopic observations, we confirm the planetary nature of TOI-1859b and determine the stellar obliquity of TOI-1859 to be ? = 38.9(-2.7)(+2.8 degrees) relative to its planetary 2.8 -companion using the Rossiter-McLaughlin effect. TOI-1859b is a 64 day warm Jupiter orbiting around a late F dwarf and has an orbital eccentricity of 0.57 ( +0.12)(-0.16) inferred purely from transit light curves. The eccentric and misaligned orbit of TOI-0.12 -1859b is likely an outcome of dynamical interactions, such as planet-planet scattering and planet-disk resonance crossing.