The Discovery of the Long-Period, Eccentric Planet Kepler-88 d and System Characterization with Radial Velocities and Photodynamical Analysis
- Institute for Astronomy, University of Hawai‘i, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
- Department of Astronomy and Astrophysics, University of Chicago, 5640 S. Ellis Avenue, Chicago, IL 60637 (United States)
- Department of Astronomy, University of Washington, Seattle, WA (United States)
- California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125 (United States)
- California Institute of Technology, Pasadena, CA 91125 (United States)
- 501 Campbell Hall, University of California at Berkeley, Berkeley, CA 94720 (United States)
- Department of Physics & Astronomy, University of California Los Angeles, Los Angeles, CA 90095 (United States)
- NASA Exoplanet Science Institute, MC 314-6, 1200 E. California Boulevard, Pasadena, CA 91125 (United States)
- Varian Physics, Room 108, 382 Via Pueblo Mall, Stanford, CA 94305 (United States)
- Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
We present the discovery of Kepler-88 d (P{sub d} = 1403±14 days, Msini{sub d}=965±44 M{sub ⊕}=3.04±0.13 M{sub J}, e{sub d}=0.41±0.03) based on six years of radial velocity (RV) follow-up from the W. M. Keck Observatory High Resolution Echelle Spectrometer spectrograph. Kepler-88 has two previously identified planets. Kepler-88 b (KOI-142.01) transits in the NASA Kepler photometry and has very large transit timing variations (TTVs). Nesvorný et al. performed a dynamical analysis of the TTVs to uniquely identify the orbital period and mass of the perturbing planet (Kepler-88 c), which was later was confirmed with RVs from the Observatoire de Haute-Provence (OHP). To fully explore the architecture of this system, we performed photodynamical modeling on the Kepler photometry combined with the RVs from Keck and OHP and stellar parameters from spectroscopy and Gaia. Planet d is not detectable in the photometry, and long-baseline RVs are needed to ascertain its presence. A photodynamical model simultaneously optimized to fit the RVs and Kepler photometry yields the most precise planet masses and orbital properties yet for b and c: P{sub b}=10.91647±0.00014 days, M{sub b}=9.5±1.2 M{sub ⊕}, P{sub c}=22.2649±0.0007 days, and M{sub c}=214.0±5.3 M{sub ⊕}. The photodynamical solution also finds that planets b and c have low eccentricites and low mutual inclination, are apsidally anti-aligned, and have conjunctions on the same hemisphere of the star. Continued RV follow-up of systems with small planets will improve our understanding of the link between inner planetary system architectures and giant planets.
- OSTI ID:
- 23013216
- Journal Information:
- Astronomical Journal (New York, N.Y. Online), Vol. 159, Issue 5; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1538-3881
- Country of Publication:
- United States
- Language:
- English
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