151 citations · 1.2k across the 43 of their papers we have counts for
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Origin of a massive hyper-runaway subgiant star LAMOST-HVS1 -- implication from Gaia and follow-up spectroscopy
Kohei Hattori, Monica Valluri, Norberto Castro +3
We report that LAMOST-HVS1 is a massive hyper-runaway subgiant star with mass of 8.3 Msun and super-Solar metallicity, ejected from the inner stellar disk of the Milky Way 3…
Kinematics of Highly R-Process-Enhanced Field Stars: Evidence for an Accretion Origin and Detection of Several Groups from Disrupted Satellites
Ian U. Roederer, Kohei Hattori, Monica Valluri
We present kinematics of 35 highly r-process-enhanced ([Eu/Fe] >= +0.7) metal-poor (-3.8 < [Fe/H] < -1.4) field stars. We calculate six-dimensional positions and velocities, evalua…
Old, Metal-Poor Extreme Velocity Stars in the Solar Neighborhood
Kohei Hattori, Monica Valluri, Eric F. Bell +1
We report the discovery of 30 stars with extreme space velocities ( 480 km/s) in the Gaia-DR2 archive. These stars are a subset of 1743 stars with high-precision parallax, large…
Constraining Solar position and velocity with a Nearby Hypervelocity Star
Kohei Hattori, Monica Valluri, Norberto Castro
Gravitational 3-body interaction among binary stars and the supermassive black hole (SMBH) at the center of the Milky Way occasionally ejects a hypervelocity star (HVS) with a velo…
Metallicity dependence of the Hercules stream in Gaia/RAVE data -- explanation by non-closed orbits
Kohei Hattori, Naoteru Gouda, Taihei Yano +4
The origin of the Hercules stream, the most prominent velocity substructure in the Solar neighbour disc stars, is still under debate. Recent accurate measurements of position, velo…