151 citations · 1.2k across the 43 of their papers we have counts for
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The R-Process Alliance: 2MASS J22132050-5137385, the Star with the Highest-known r-process Enhancement at [Eu/Fe] = +2.45
Ian U. Roederer, Timothy C. Beers, Kohei Hattori +6
We present stellar parameters and chemical abundances of 47 elements detected in the bright (V = 11.63) very metal-poor ([Fe/H] = -2.20 +- 0.12) star 2MASS J22132050-5137385. We ob…
Search for a Black Hole Binary in Gaia DR3 Astrometric Binary Stars with Spectroscopic Data
Ataru Tanikawa, Kohei Hattori, Norita Kawanaka +3
We report the discovery of a candidate binary system consisting of a black hole (BH) and a red giant branch star from the Gaia DR3. This binary system is discovered from 64108 bina…
The R-Process Alliance: A Nearly Complete R-Process Abundance Template Derived from Ultraviolet Spectroscopy of the R-Process-Enhanced Metal-Poor Star HD 222925
Ian U. Roederer, James E. Lawler, Elizabeth A. Den Hartog +9
We present a nearly complete rapid neutron-capture process (r-process) chemical inventory of the metal-poor ([Fe/H] = -1.46 +/- 0.10) r-process-enhanced ([Eu/Fe] = +1.32 +/- 0.08)…
A Very Metal-poor RR Lyrae Star with a Disk Orbit Found in the Solar Neighborhood
Noriyuki Matsunaga, Akinori Itane, Kohei Hattori +28
Metal-deficient stars are important tracers for understanding the early formation of the Galaxy. Recent large-scale surveys with both photometric and spectroscopic data have report…
The Southern Stellar Stream Spectroscopic Survey (S5): Chemical Abundances of Seven Stellar Streams
Alexander P. Ji, Ting S. Li, Terese T. Hansen +16
We present high-resolution Magellan/MIKE spectroscopy of 42 red giant stars in seven stellar streams confirmed by the Southern Stellar Stream Spectroscopic Survey (S5): ATLAS, Aliq…
The R-Process Alliance: J1521-3538, a very metal-poor, extremely r-process-enhanced star with [Eu/Fe]=+2.2, and the class of r-III stars
Madelyn Cain, Anna Frebel, Alexander P. Ji +8
We report the discovery of J1521-3538, a bright (V=12.2), very metal-poor ([Fe/H]=-2.8) strongly r-process enhanced field horizontal branch star, based on a high-resolution, high s…
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…