Updated Planetary Mass Constraints of the Young V1298 Tau System Using MAROON-X

June 2023 • 2023AJ....165..250S

Authors • Sikora, James • Rowe, Jason • Barat, Saugata • Bean, Jacob L. • Brady, Madison • Désert, Jean-Michel • Feinstein, Adina D. • Gilbert, Emily A. • Henry, Gregory • Kasper, David • Lizotte, Déreck-Alexandre • Matesic, Michael R. B. • Panwar, Vatsal • Seifahrt, Andreas • Shivkumar, Hinna • Stefánsson, Gudmundur • Stürmer, Julian

Abstract • The early K-type T-Tauri star, V1298 Tau (V = 10 mag, age ≈ 20-30 Myr) hosts four transiting planets with radii ranging from 4.9 to 9.6 R _⊕. The three inner planets have orbital periods of ≈8-24 days while the outer planet's period is poorly constrained by single transits observed with K2 and the Transiting Exoplanet Survey Satellite (TESS). Planets b, c, and d are proto-sub-Neptunes that may be undergoing significant mass loss. Depending on the stellar activity and planet masses, they are expected to evolve into super-Earths/sub-Neptunes that bound the radius valley. Here we present results of a joint transit and radial velocity (RV) modeling analysis, which includes recently obtained TESS photometry and MAROON-X RV measurements. Assuming circular orbits, we obtain a low-significance (≈2σ) RV detection of planet c, implying a mass of ${19.8}_{-8.9}^{+9.3}\,{M}_{\oplus }$ and a conservative 2σ upper limit of <39 M _⊕. For planets b and d, we derive 2σ upper limits of M _b < 159 M _⊕ and M _d < 41 M _⊕, respectively. For planet e, plausible discrete periods of P _e > 55.4 days are ruled out at the 3σ level while seven solutions with 43.3 < P _e/d < 55.4 are consistent with the most probable 46.768131 ± 000076 days solution within 3σ. Adopting the most probable solution yields a 2.6σ RV detection with a mass of 0.66 ± 0.26 M _Jup. Comparing the updated mass and radius constraints with planetary evolution and interior structure models shows that planets b, d, and e are consistent with predictions for young gas-rich planets and that planet c is consistent with having a water-rich core with a substantial (~5% by mass) H₂ envelope.

Links

• PREPRINT http://arxiv.org/abs/2304.00797
• ELECTR https://doi.org/10.3847/1538-3881/acc865
• SIMBAD https://simbad.u-strasbg.fr/simbad/sim-ref?querymethod=bib&simbo=on&submit=submit+bibcode&bibcode=2023AJ....165..250S
• PDF https://iopscience.iop.org/article/10.3847/1538-3881/acc865/pdf
• DATA https://archive.gemini.edu/searchform/publication=2023AJ....165..250S
• DATA https://doi.org/10.17909/72nn-2166