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14 Her: A Likely Case of Planet–Planet Scattering

Bardalez Gagliuffi, Daniella C. and Faherty, Jacqueline K. and Li, Yiting and Brandt, Timothy D. and Williams, Lauryn and Brandt, G. Mirek and Gelino, Christopher R. (2021) 14 Her: A Likely Case of Planet–Planet Scattering. Astrophysical Journal Letters, 922 (2). Art. No. L43. ISSN 2041-8205. doi:10.3847/2041-8213/ac382c.

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In this Letter, we measure the full orbital architecture of the two-planet system around the nearby K0 dwarf 14 Herculis. 14 Her (HD 145675, HIP 79248) is a middle-aged (4.6_(-1.3)^(+3.8) Gyr) K0 star with two eccentric giant planets identified in the literature from radial velocity (RV) variability and long-term trends. Using archival RV data from Keck/HIRES in concert with Gaia-Hipparcos acceleration in the proper motion vector for the star, we have disentangled the mass and inclination of the b planet to 9.1_(-1.1)^(+1.0) M_(Jup) and 32.7)_(-3.2)^(+5.3) degrees. Despite only partial phase coverage for the c planet's orbit, we are able to constrain its mass and orbital parameters as well to 6.9_(-1.0)^(+1.7) M_(Jup) and 101_(-33)^(+31) degrees. We find that coplanarity of the b and c orbits is strongly disfavored. Combined with the age of the system and the comparable masses of its planets, this suggests that planet–planet scattering may be responsible for the current configuration of the system.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Bardalez Gagliuffi, Daniella C.0000-0001-8170-7072
Faherty, Jacqueline K.0000-0001-6251-0573
Li, Yiting0000-0002-6845-9702
Brandt, Timothy D.0000-0003-2630-8073
Williams, Lauryn0000-0002-0604-5440
Brandt, G. Mirek0000-0003-0168-3010
Additional Information:© 2021. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2021 October 13; revised 2021 November 9; accepted 2021 November 10; published 2021 December 3. We thank the referee and editor for their helpful comments. We thank Sean Raymond for fruitful dynamical discussion about planet–planet scattering. This work has made use of data from the European Space Agency (ESA) mission Gaia (, processed by the Gaia Data Processing and Analysis Consortium (DPAC, Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Facilities: Keck(HIRES) - , Hipparcos - , Gaia - , Exoplanet Archive - . Software: astropy (Astropy Collaboration et al. 2013), orvara (Brandt et al. 2021b), SPLAT (Burgasser & Splat Development Team 2017).
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Gaia Multilateral AgreementUNSPECIFIED
Subject Keywords:Exoplanet dynamics; Exoplanet formation; Exoplanet evolution; Exoplanet detection methods; Astrometric exoplanet detection; Radial velocity; Y dwarfs
Issue or Number:2
Classification Code:Unified Astronomy Thesaurus concepts: Exoplanet dynamics (490); Exoplanet formation (492); Exoplanet evolution (491); Exoplanet detection methods (489); Astrometric exoplanet detection (2130); Radial velocity (1332); Y dwarfs (1827)
Record Number:CaltechAUTHORS:20211207-393936000
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Official Citation:Daniella C. Bardalez Gagliuffi et al 2021 ApJL 922 L43
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:112257
Deposited By: George Porter
Deposited On:07 Dec 2021 20:34
Last Modified:01 Feb 2022 22:58

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