Search Publications
The Hipparcos-Gaia Catalog of Accelerations: Gaia EDR3 Edition
Brandt, Timothy D.
We present a cross-calibration of Hipparcos and Gaia EDR3 intended to identify astrometrically accelerating stars and to fit orbits to stars with faint, massive companions. The resulting catalog, the EDR3 edition of the Hipparcos-Gaia Catalog of Accelerations (HGCA), provides three proper motions with calibrated uncertainties on the EDR3 reference…
orvara: An Efficient Code to Fit Orbits Using Radial Velocity, Absolute, and/or Relative Astrometry
Dupuy, Trent J.; Bardalez Gagliuffi, Daniella C.; Brandt, Timothy D. +5 more
We present an open-source Python package, Orbits from Radial Velocity, Absolute, and/or Relative Astrometry (orvara), to fit Keplerian orbits to any combination of radial velocity, relative astrometry, and absolute astrometry data from the Hipparcos-Gaia Catalog of Accelerations. By combining these three data types, one can measure precise masses …
Improved Dynamical Masses for Six Brown Dwarf Companions Using Hipparcos and Gaia EDR3
Currie, Thayne; Dupuy, Trent J.; Bowler, Brendan P. +8 more
We present comprehensive orbital analyses and dynamical masses for the substellar companions Gl 229 B, Gl 758 B, HD 13724 B, HD 19467 B, HD 33632 Ab, and HD 72946 B. Our dynamical fits incorporate radial velocities, relative astrometry, and, most importantly, calibrated Hipparcos-Gaia EDR3 accelerations. For HD 33632 A and HD 72946 we perform thre…
Precise Dynamical Masses and Orbital Fits for β Pic b and β Pic c
Dupuy, Trent J.; Brandt, Timothy D.; Li, Yiting +2 more
We present a comprehensive orbital analysis to the exoplanets β Pictoris b and c that resolves previously reported tensions between the dynamical and evolutionary mass constraints on β Pic b. We use the Markov Chain Monte Carlo orbit code orvara to fit 15 years of radial velocities and relative astrometry (including recent GRAVITY measurements), a…
Distances to Galactic X-ray binaries with Gaia DR2
Barmby, P.; Bahramian, A.; Arnason, R. M. +2 more
Precise and accurate measurements of distances to Galactic X-ray binaries (XRBs) reduce uncertainties in the determination of XRB physical parameters. We have cross-matched the XRB catalogues of Liu, van Paradijs & van den Heuvel to the results of Gaia Data Release 2. We identify 86 XRBs with a Gaia candidate counterpart, of which 32 are low-m…
Medium-resolution spectrum of the exoplanet HIP 65426 b
D'Orazi, V.; Boccaletti, A.; Lagrange, A. -M. +18 more
Medium-resolution integral-field spectrographs (IFS) coupled with adaptive-optics such as Keck/OSIRIS, VLT/MUSE, or SINFONI are appearing as a new avenue for enhancing the detection and characterization capabilities of young, gas giant exoplanets at large heliocentric distances (>5 au). We analyzed K-band VLT/SINFONI medium-resolution (Rλ<…
The First Dynamical Mass Measurement in the HR 8799 System
Dupuy, Trent J.; Brandt, Timothy D.; Brandt, G. Mirek +2 more
HR 8799 hosts four directly imaged giant planets, but none has a mass measured from first principles. We present the first dynamical mass measurement in this planetary system, finding that the innermost planet HR 8799 e has a mass of ${9.6}_{-1.8}^{+1.9}\,{M}_{\mathrm{Jup}}$ . This mass results from combining the well-characterized orbits of all f…
Characterizing Undetected Stellar Companions with Combined Data Sets
Kraus, Adam L.; Mann, Andrew W.; Wood, Mackenna L.
Binaries play a critical role in the formation, evolution, and fundamental properties of planets, stars, and stellar associations. Observational studies in these areas often include a mix of observations aimed at detecting or ruling out the presence of stellar companions. Rarely can nondetections rule out all possible binary configurations. Here w…
All-sky visible and near infrared space astrometry
Tanga, Paolo; Ting, Yuan-Sen; Zwitter, Tomaž +27 more
The era of all-sky space astrometry began with the Hipparcos mission in 1989 and provided the first very accurate catalogue of apparent magnitudes, positions, parallaxes and proper motions of 120 000 bright stars at the milliarcsec (or milliarcsec per year) accuracy level. Hipparcos has now been superseded by the results of the Gaia mission. The s…
TIC 168789840: A Sextuply Eclipsing Sextuple Star System
Kostov, Veselin B.; Powell, Brian P.; Rappaport, Saul A. +48 more
We report the discovery of a sextuply eclipsing sextuple star system from TESS data, TIC 168789840, also known as TYC 7037-89-1, the first known sextuple system consisting of three eclipsing binaries. The target was observed in Sectors 4 and 5 during Cycle 1, with lightcurves extracted from TESS Full Frame Image data. It was also previously observ…