The Misaligned Orbit of the Earth-sized Planet Kepler-408b

Shoya Kamiaka, Othman Benomar, Yasushi Suto, Fei Dai, Kento Masuda, Joshua N. Winn

    Research output: Contribution to journalArticle

    Abstract

    Kepler-408 is one of the 33 planet-hosting Kepler stars for which asteroseismology has been used to investigate the orientation of the stellar rotation axis relative to the planetary orbital plane. The transiting hot Earth, Kepler-408b, has an orbital period of 2.5 days and a radius of 0.86 R , making it much smaller than the planets for which spin-orbit alignment has been studied using the Rossiter-McLaughlin effect. Because conflicting asteroseismic results have been reported in the literature, we undertake a thorough re-appraisal of this system and perform numerous checks for consistency and robustness. We find that the conflicting results are due to the different models for the low-frequency noise in the power spectrum. A careful treatment of the background noise resolves these conflicts, and shows that the stellar inclination is i∗ = 42+5 -4 degrees. Kepler-408b is, by far, the smallest planet known to have a significantly misaligned orbit.

    Original languageEnglish (US)
    Article number137
    JournalAstronomical Journal
    Volume157
    Issue number4
    DOIs
    StatePublished - Apr 1 2019

    Fingerprint

    planets
    planet
    orbits
    asteroseismology
    stellar rotation
    orbitals
    background noise
    inclination
    power spectra
    alignment
    low frequencies
    stars
    radii
    effect
    appraisal
    conflict

    Keywords

    • asteroseismology
    • methods: data analysis
    • planetary systems
    • stars: oscillations
    • stars: rotation
    • techniques: photometric

    ASJC Scopus subject areas

    • Astronomy and Astrophysics
    • Space and Planetary Science

    Cite this

    Kamiaka, S., Benomar, O., Suto, Y., Dai, F., Masuda, K., & Winn, J. N. (2019). The Misaligned Orbit of the Earth-sized Planet Kepler-408b. Astronomical Journal, 157(4), [137]. https://doi.org/10.3847/1538-3881/ab04a9

    The Misaligned Orbit of the Earth-sized Planet Kepler-408b. / Kamiaka, Shoya; Benomar, Othman; Suto, Yasushi; Dai, Fei; Masuda, Kento; Winn, Joshua N.

    In: Astronomical Journal, Vol. 157, No. 4, 137, 01.04.2019.

    Research output: Contribution to journalArticle

    Kamiaka, S, Benomar, O, Suto, Y, Dai, F, Masuda, K & Winn, JN 2019, 'The Misaligned Orbit of the Earth-sized Planet Kepler-408b', Astronomical Journal, vol. 157, no. 4, 137. https://doi.org/10.3847/1538-3881/ab04a9
    Kamiaka S, Benomar O, Suto Y, Dai F, Masuda K, Winn JN. The Misaligned Orbit of the Earth-sized Planet Kepler-408b. Astronomical Journal. 2019 Apr 1;157(4). 137. https://doi.org/10.3847/1538-3881/ab04a9
    Kamiaka, Shoya ; Benomar, Othman ; Suto, Yasushi ; Dai, Fei ; Masuda, Kento ; Winn, Joshua N. / The Misaligned Orbit of the Earth-sized Planet Kepler-408b. In: Astronomical Journal. 2019 ; Vol. 157, No. 4.
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