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The Two Metallicity Groups Of The Globular Cluster M22: A Chemical Perspective
(2011-08)
We present a detailed chemical composition analysis of 35 red giant stars in the globular cluster M22. High resolution spectra for this study were obtained at five observatories, and analyzed in a uniform manner. We have ...
Chemical Abundances For Evolved Stars In M5: Lithium Through Thorium
(2011-02)
We present analysis of high-resolution spectra of a sample of stars in the globular cluster M5 (NGC 5904). The sample includes stars from the red giant branch (RGB; seven stars), the red horizontal branch (two stars), and ...
Improved Ni I Log(gf) Values and Abundance Determinations in the Photospheres of the Sun and Metal-Poor Star HD 84937
(2014-04)
Atomic transition probability measurements for 371 Ni I lines in the UV through near-IR are reported. Branching fractions from data recorded using a Fourier transform spectrometer and a new echelle spectrograph are combined ...
Characterizing The Heavy Elements In Globular Cluster M22 And An Empirical S-Process Abundance Distribution Derived From The Two Stellar Groups
(2011-11)
We present an empirical s-process abundance distribution derived with explicit knowledge of the r-process component in the low-metallicity globular cluster M22. We have obtained high-resolution, high signal-to-noise spectra ...
Searching For Chemical Signatures Of Multiple Stellar Populations In The Old, Massive Open Cluster NGC 6791
(2014-11)
Galactic open and globular clusters (OCs, GCs) appear to inhabit separate regions of the age-mass plane. However, the transition between them is not easily defined because there is some overlap between high-mass, old OCs ...
Improved V I Log(gf) Values and Abundance Determinations in the Photospheres of the Sun and Metal-Poor Star HD 84937
(2014-12)
New emission branching fraction measurements for 836 lines of the first spectrum of vanadium (V I) are determined from hollow cathode lamp spectra recorded with the National Solar Observatory 1 m Fourier transform spectrometer ...
Improved Log(gf) Values for Lines of Ti I and Abundance Determinations in the Photospheres of the Sun and Metal-Poor Star HD 84937 (Accurate Transition Probabilities for Ti I)
(2013-04)
New atomic transition probability measurements for 948 lines of Ti I are reported. Branching fractions from Fourier transform spectra and from spectra recorded using a 3 m echelle spectrometer are combined with published ...
New Detections Of Arsenic, Selenium, And Other Heavy Elements In Two Metal-Poor Stars
(2014-08)
We use the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope to obtain new high-quality spectra covering the 1900 <= lambda <= 2360 angstrom wavelength range for two metal-poor stars, HD 108317 and ...
The Two Metallicity Groups Of The Globular Cluster M22: A Chemical Perspective
(2011-08)
We present a detailed chemical composition analysis of 35 red giant stars in the globular cluster M22. High resolution spectra for this study were obtained at five observatories, and analyzed in a uniform manner. We have ...
Silicon And Oxygen Abundances In Planet-Host Stars
(2011-09)
The positive correlation between planet detection rate and host star iron abundance lends strong support to the core accretion theory of planet formation. However, iron is not the most significant mass contributor to the ...