Giant Outer Transiting Exoplanet Mass (GOT ‘EM) Survey. II. Discovery of a Failed Hot Jupiter on a 2.7 Yr, Highly Eccentric Orbit

Journal Article · Fri Oct 01 04:00:00 EDT 2021 · The Astronomical Journal (Online)

DOI:https://doi.org/10.3847/1538-3881/AC134B· OSTI ID:23159376

Dalba, Paul A.; Kane, Stephen R.; Li, Zhexing; Schwieterman, Edward W. ^[1]; MacDougall, Mason G.; Petigura, Erik A. ^[2]; Rosenthal, Lee J.; Cherubim, Collin; Howard, Andrew W. ^[3]; Isaacson, Howard ^[4]; Thorngren, Daniel P. ^[5]; Fulton, Benjamin ^[6]; Peluso, Dan O. ^[7]; Esposito, Thomas M.; Marchis, Franck ^[8]

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1. Department of Earth and Planetary Sciences, University of California Riverside, 900 University Avenue, Riverside, CA 92521 (United States)
2. Department of Physics & Astronomy, University of California Los Angeles, Los Angeles, CA 90095 (United States)
3. Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States)
4. Department of Astronomy, University of California Berkeley, Berkeley, CA 94720 (United States)
5. Institute for Research on Exoplanets (iREx), Université de Montréal (Canada)
6. NASA Exoplanet Science Institute/Caltech-IPAC, MC 314-6, 1200 E. California Boulevard, Pasadena, CA 91125 (United States)
7. Centre for Astrophysics, University of Southern Queensland, Toowoomba, QLD (Australia)
8. SETI Institute, Carl Sagan Center, 189 Bernardo Avenue, Mountain View, CA (United States)

Radial velocity (RV) surveys have discovered giant exoplanets on au-scale orbits with a broad distribution of eccentricities. Those with the most eccentric orbits are valuable laboratories for testing theories of high-eccentricity migration. However, few such exoplanets transit their host stars, thus removing the ability to apply constraints on formation from their bulk internal compositions. We report the discovery of Kepler-1704 b, a transiting 4.15 M {sub J} giant planet on a 988.88 day orbit with an extreme eccentricity of 0.921{sub -0.015}{sup +0.010}. Our decade-long RV baseline from the Keck I telescope allows us to measure the orbit and bulk heavy-element composition of Kepler-1704 b and place limits on the existence of undiscovered companions. A failed hot Jupiter, Kepler-1704 b was likely excited to high eccentricity by scattering events that possibly began during its gas accretion phase. Its final periastron distance was too large to allow for tidal circularization, so now it orbits its host from distances spanning 0.16–3.9 au. The maximum difference in planetary equilibrium temperature resulting from this elongated orbit is over 700 K. A simulation of the thermal phase curve of Kepler-1704 b during periastron passage demonstrates that it is a remarkable target for atmospheric characterization from the James Webb Space Telescope, which could potentially also measure the planet’s rotational period as the hot spot from periastron rotates in and out of view. Continued characterization of the Kepler-1704 system promises to refine theories explaining the formation of hot Jupiters and cool giant planets like those in the solar system.

• OSTI ID: 23159376
• Journal Information: The Astronomical Journal (Online), Journal Name: The Astronomical Journal (Online) Journal Issue: 4 Vol. 162; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

47 OTHER INSTRUMENTATION
79 ASTRONOMY AND ASTROPHYSICS
COMPUTERIZED SIMULATION
HOT SPOTS
JUPITER PLANET
ORBITS
RADIAL VELOCITY
SCATTERING
SOLAR SYSTEM
SPACE
STARS
TELESCOPES
TESTING