Search Publications
Astrometric Accelerations as Dynamical Beacons: Discovery and Characterization of HIP 21152 B, the First T-dwarf Companion in the Hyades
Magnier, Eugene A.; Jensen-Clem, Rebecca; Crepp, Justin R. +28 more
Benchmark brown dwarf companions with well-determined ages and model-independent masses are powerful tools to test substellar evolutionary models and probe the formation of giant planets and brown dwarfs. Here, we report the independent discovery of HIP 21152 B, the first imaged brown dwarf companion in the Hyades, and conduct a comprehensive orbi…
The McDonald Accelerating Stars Survey: Architecture of the Ancient Five-planet Host System Kepler-444
Cochran, William D.; Endl, Michael; Isaacson, Howard T. +11 more
We present the latest and most precise characterization of the architecture for the ancient (≈11 Gyr) Kepler-444 system, which is composed of a K0 primary star (Kepler-444 A) hosting five transiting planets and a tight M-type spectroscopic binary (Kepler-444 BC) with an A-BC projected separation of 66 au. We have measured the system's relative ast…
First VLTI/GRAVITY Observations of HIP 65426 b: Evidence for a Low or Moderate Orbital Eccentricity
Lutz, D.; Genzel, R.; Sturm, E. +96 more
Giant exoplanets have been directly imaged over orders of magnitude of orbital separations, prompting theoretical and observational investigations of their formation pathways. In this paper, we present new VLTI/GRAVITY astrometric data of HIP 65426 b, a cold, giant exoplanet which is a particular challenge for most formation theories at a projecte…
Dynamical Mass of the Young Brown Dwarf Companion PZ Tel B
Bowler, Brendan P.; Franson, Kyle
Dynamical masses of giant planets and brown dwarfs are critical tools for empirically validating substellar evolutionary models and their underlying assumptions. We present a measurement of the dynamical mass and an updated orbit of PZ Tel B, a young brown dwarf companion orbiting a late-G member of the β Pic moving group. PZ Tel A exhibits an ast…
Revisiting Orbital Evolution in HAT-P-2 b and Confirmation of HAT-P-2 c
Fulton, Benjamin J.; Howard, Andrew W.; Winn, Joshua N. +5 more
One possible formation mechanism for Hot Jupiters is that high-eccentricity gas giants experience tidal interactions with their host star that cause them to lose orbital energy and migrate inwards. We study these types of tidal interactions in an eccentric Hot Jupiter called HAT-P-2 b, which is a system where a long-period companion has been sugge…
Dynamics of Four Triple Systems
Tokovinin, Andrei
Orbital motions in four hierarchical stellar systems discovered by speckle interferometry are studied. Their inner orbits are relatively well constrained, while the long outer orbits are less certain. The eccentric and misaligned inner orbits in the early-type hierarchies ϵ Cha (B9V, central star of the 5 Myr old association, P = 6.4 yr, e = 0.73)…
A Catalog of Nearby Accelerating Star Candidates in Gaia DR3
Kenyon, Scott J.; Bromley, Benjamin C.; Whiting, Marc L. +1 more
We describe a new catalog of accelerating star candidates with Gaia G ≤ 17.5 mag and distances d ≤ 100 pc. Designated as the Gaia Nearby Accelerating Star Catalog (GNASC), it contains 29,684 members identified using a supervised machine-learning algorithm trained on the Hipparcos-Gaia Catalog of Accelerations (HGCA), Gaia Data Release 2, and Gaia …
The 14 Her Planetary System: Companion Masses and Architecture from Radial Velocities and Astrometry
McArthur, B. E.; Benedict, G. F.; Nelan, E. P. +1 more
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 Ho…
Spectroscopic Orbits of Subsystems in Multiple Stars. IX
Tokovinin, Andrei
New spectroscopic orbits of inner subsystems in 14 hierarchies are determined from long-term monitoring with the optical echelle spectrometer, CHIRON. Their main components are nearby solar-type stars belonging to nine triple systems (HIP 3645, 14307, 36165, 79980, 103735, 103814, 104440, 105879, 109443) and five quadruples of 2 + 2 hierarchy (HIP…
A Study of Eight Visual-spectroscopic Southern Binaries Using Recent SOAR Observations
Docobo, José A.; Campo, Pedro P.; Costa, Edgardo +2 more
Speckle observations performed between 2019 and 2022 with the HRCam attached to the 4.1 m SOAR telescope (Cerro Pachón, Chile) permitted to improve visual orbits of the southern binaries WDS 01243-0655 (BU 1163), WDS 09275-5806 (CHR 240), WDS 12114-1647 (S 643 AaAb), WDS 13317-0219 (HDS 1895), WDS 15282-0921 (BAG 25 AaAb), WDS 17304-0104 (STF 2173…