The TESS-Keck Survey. XVIII. A sub-Neptune and spurious long-period signal in the TOI-1751 system

We present and confirm TOI-1751 b, a transiting sub-Neptune orbiting a slightly evolved, solar-type, metal-poor star (\(T_{eff} = 5996 \pm 110\) K, \(log(g) = 4.2 \pm 0.1\), V = 9.3 mag, [Fe/H] = \(-0.40 \pm 0.06\) dex) every 37.47 d. We use TESS photometry to measure a planet radius of \(2.77_{-0.0...

Full description

Saved in:
Bibliographic Details
Published in:arXiv.org 2024-02
Main Authors: Desai, Anmol, Turtelboom, Emma V, Harada, Caleb K, Dressing, Courtney D, Rice, David R, Akana Murphy, Joseph M, Brinkman, Casey L, Chontos, Ashley, Crossfield, Ian J M, Dai, Fei, Hill, Michelle L, Fetherolf, Tara, Giacalone, Steven, Howard, Andrew W, Huber, Daniel, Isaacson, Howard, Kane, Stephen R, Lubin, Jack, MacDougall, Mason G, Mayo, Andrew W, Teo Močnik, Polanski, Alex S, Rice, Malena, Robertson, Paul, Rubenzahl, Ryan A, Judah Van Zandt, Weiss, Lauren M, Bieryla, Allyson, Buchhave, Lars A, Jenkins, Jon M, Kostov, Veselin B, Levine, Alan M, Lillo-Box, Jorge, Paegert, M, Rabus, Markus, Seager, S, Stassun, Keivan G, Ting, Eric B, Watanabe, David, Winn, Joshua N
Format: Article
Language:English
Subjects:
Metallicity
Neptune
Observatories
Ocean models
Planetary composition
Window functions
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We present and confirm TOI-1751 b, a transiting sub-Neptune orbiting a slightly evolved, solar-type, metal-poor star (\(T_{eff} = 5996 \pm 110\) K, \(log(g) = 4.2 \pm 0.1\), V = 9.3 mag, [Fe/H] = \(-0.40 \pm 0.06\) dex) every 37.47 d. We use TESS photometry to measure a planet radius of \(2.77_{-0.07}^{+0.15}~\rm{R_\oplus}\). We also use both Keck/HIRES and APF/Levy radial velocities (RV) to derive a planet mass of \(14.5_{-3.14}^{+3.15} ~\rm{M_\oplus}\), and thus a planet density of \(3.6 \pm 0.9 \, {\rm g}\,{\rm cm}^{-3}\). There is also a long-period (\(\sim400~\rm{d}\)) signal that is observed in only the Keck/HIRES data. We conclude that this long-period signal is not planetary in nature, and is likely due to the window function of the Keck/HIRES observations. This highlights the role of complementary observations from multiple observatories to identify and exclude aliases in RV data. Finally, we investigate potential compositions of this planet, including rocky and water-rich solutions, as well as theoretical irradiated ocean models. TOI-1751 b is a warm sub-Neptune, with an equilibrium temperature of \(\sim 820\) K. As TOI-1751 is a metal-poor star, TOI-1751 b may have formed in a water-enriched formation environment. We thus favor a volatile-rich interior composition for this planet.
ISSN:2331-8422