Imaging & Spectroscopy

Giant Outer Transiting Exoplanet Mass (GOT ‘EM) Survey. IV. Long-term Doppler Spectroscopy for 11 Stars Thought to Host Cool Giant Exoplanets

By Keith Cowing
Status Report
January 10, 2024
Giant Outer Transiting Exoplanet Mass (GOT ‘EM) Survey. IV. Long-term Doppler Spectroscopy for 11 Stars Thought to Host Cool Giant Exoplanets
Transits and model of Kepler-111 c, including both short and long cadence Kepler data. Each transit is shown to demonstrate the convergence of the TTV model. In the lower right column, all data have been folded on the maximum likelihood transit ephemeris. astro-ph.EP

Discovering and characterizing exoplanets at the outer edge of the transit method’s sensitivity has proven challenging owing to geometric biases and the practical difficulties associated with acquiring long observational baselines.

Nonetheless, a sample of giant exoplanets on orbits longer than 100 days has been identified by transit hunting missions. We present long-term Doppler spectroscopy for 11 such systems with observation baselines spanning a few years to a decade. We model these radial velocity observations jointly with transit photometry to provide initial characterizations of these objects and the systems in which they exist.

Specifically, we make new precise mass measurements for four long-period giant exoplanets (Kepler-111 c, Kepler-553 c, Kepler-849 b, and PH-2 b), we place new upper limits on mass for four others (Kepler-421 b, KOI-1431.01, Kepler-1513 b, and Kepler-952 b), and we show that several “confirmed” planets are in fact not planetary at all.

We present these findings to complement similar efforts focused on closer-in short-period giant planets, and with the hope of inspiring future dedicated studies of cool giant exoplanets.

Paul A. Dalba, Stephen R. Kane, Howard Isaacson, Benjamin Fulton, Andrew W. Howard, Edward W. Schwieterman, Daniel P. Thorngren, Jonathan Fortney, Noah Vowell, Corey Beard, Sarah Blunt, Casey L. Brinkman, Ashley Chontos, Fei Dai, Steven Giacalone, Michelle L. Hill, Molly Kosiarek, Jack Lubin, Andrew W. Mayo, Teo Mocnik, Joseph M. Akana Murphy, Erik A. Petigura, Malena Rice, Ryan A. Rubenzahl, Judah Van Zandt, Lauren M. Weiss, Diana Dragomir, David Kipping, Matthew J. Payne, Arpita Roy, Alex Teachey, Steven Villanueva Jr

Comments: 35 pages, 24 figures, 11 tables. Accepted for publication in ApJ Supplement
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2401.03021 [astro-ph.EP] (or arXiv:2401.03021v1 [astro-ph.EP] for this version)
Submission history
From: Paul Dalba
[v1] Fri, 5 Jan 2024 19:00:03 UTC (3,754 KB)

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻