The 14 Her Planetary System: Companion Masses and Architecture from Radial Velocities and Astrometry

Abstract

We combine Hubble Space Telescope (HST) Fine Guidance Sensor, Hipparcos, and Gaia DR3 astrometric observations of the K0 V star 14 Her with the results of an analysis of extensive ground-based radial velocity data to determine perturbation orbits and masses for two previously known companions, 14 Her b and c. Radial velocities obtained with the Hobby-Eberly Telescope and from the literature now span over twenty five years. With these data we obtain improved RV orbital elements for both the inner companion, 14 Her b and the long-period outer companion, 14 Her c. We also find evidence of an additional RV signal with P $/sim$ 3789d. We then model astrometry from Hipparcos, HST, and Gaia with RV results to obtain system parallax and proper motion, perturbation periods, inclinations, and sizes due to 14 Her b and c. We find P_b = 1767.6 +/- 0.2 d, perturbation semi-major axis α_b = 1.3 +/- 0.1 mas, and inclination i_b = 36 +/- 3 degrees, P_c = 52160 +/- 1028 d, perturbation semi-major axis α_c = 10.3 +/- 0.7 mas, and inclination i_c = 82 +/- 14 degrees. In agreement with a past investigation, the 14 Her b, c orbits exhibit significant mutual inclination. Assuming a primary mass M = 0.98 +/- 0.04Msun, we obtain companion masses M_b = 8.5 +/- 1.0Mjup and M_c = 7.1 +/- 1.0Mjup.

To appear in the Astronomical Journal. arXiv admin note: substantial text overlap with arXiv:2204.13706

References in corpus (17)

• Gaia Data Release 1: Astrometry - one billion positions, two million proper motions and parallaxes
• The Hipparcos-Gaia Catalog of Accelerations: Gaia EDR3 Edition
• Parallax Systematics and Photocenter Motions of Benchmark Eclipsing Binaries in Gaia EDR3
• The Solar Neighborhood XXXVII: The Mass-Luminosity Relation for Main Sequence M Dwarfs
• The Extrasolar Planet epsilon Eridani b - Orbit and Mass
• Four New Exoplanets and Hints of Additional Substellar Companions to Exoplanet Host Stars
• The Mount Wilson Observatory S-index of the Sun
• Solar cyclic activity over the last millennium reconstructed from annual 14C data
• 3-D selection of 167 sub-stellar companions to nearby stars
• The Mass of the Candidate Exoplanet Companion to HD 33636 from Hubble Space Telescope Astrometry and High-Precision Radial Velocities
• Long-Period Objects in the Extrasolar Planetary Systems 47 UMa and 14 Her
• Understanding the Impacts of Stellar Companions on Planet Formation and Evolution: A Survey of Stellar and Planetary Companions within 25 pc
• Astrometry with Hubble Space Telescope Fine Guidance Sensors - A Review
• Long-term stellar activity variations and their effect on radial-velocity measurements
• HD 202206 : A Circumbinary Brown Dwarf System
• The mu Arae planetary system: Radial velocities and astrometry
• The eta Aquilae System: Radial Velocities and Astrometry in Search of eta Aql B

Cited by in corpus (2)

• HD 28185 Revisited: An Outer Planet, Instead of a Brown Dwarf, On a Saturn-like Orbit
• Updated Mutual Inclination Measurement for 14 Her b and c