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Improved Ni I Log(gf) Values and Abundance Determinations in the Photospheres of the Sun and Metal-Poor Star HD 84937

Wood, M. P.; Lawler, James E.; Sneden, Christopher; Cowan, John J. (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 ...

The Abundances Of Neutron-Capture Species In The Very Metal-Poor Globular Cluster M15: A Uniform Analysis Of Red Giant Branch And Red Horizontal Branch Stars

Sobeck, Jennifer S.; Kraft, Robert P.; Sneden, Christopher; Preston, George W.; Cowan, John J.; Smith, Graeme H.; Thompson, Ian B.; Shectman, Stephen A.; Burley, Gregory S. (2011-06)

The globular cluster M15 is unique in its display of star-to-star variations in the neutron-capture elements. Comprehensive abundance surveys have been previously conducted for handfuls of M15 red giant branch (RGB) and ...

Improved V I Log(gf) Values and Abundance Determinations in the Photospheres of the Sun and Metal-Poor Star HD 84937

Lawler, James E.; Wood, M. P.; Den Hartog, E. A.; Feigenson, T.; Sneden, Christopher; Cowan, John J. (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 ...

New Hubble Space Telescope Observations of Heavy Elements in Four Metal-Poor Stars

Roederer, Ian U.; Lawler, James E.; Sobeck, Jennifer S.; Beers, Timothy C.; Cowan, John J.; Frebel, Anna; Ivans,, Inese I.; Schatz, Hendrik; Sneden, Christopher; Thompson, Ian B. (2012-12)

Elements heavier than the iron group are found in nearly all halo stars. A substantial number of these elements, key to understanding neutron-capture nucleosynthesis mechanisms, can only be detected in the near-ultraviolet. ...

First Stars XVI. HST/STIS Abundances Of Heavy Elements In The Uranium-Rich Metal-Poor Star CS 31082-001

Mello, C. Siqueira; Spite, M.; Barbuy, B.; Spite, F.; Caffau, E.; Hill, V.; Wanajo, S.; Primas, F.; Plez, B.; Cayrel, R.; Andersen, J.; Nordstrom, B.; Sneden, Christopher; Beers, T. C.; Bonifacio, P.; Francois, P.; Molaro, P. (2013-02)

Context. The origin and site(s) of the r-process nucleosynthesis is(are) still not known with certainty, but complete, detailed r-element abundances off er our best clues. The few extremely metal-poor (EMP) stars with large ...

A Search For Stars Of Very Low Metal Abundance. VI. Detailed Abundances Of 313 Metal-Poor Stars

Roederer, Ian U.; Preston, George W.; Thompson, Ian B.; Shectman, Stephen A.; Sneden, Christopher; Burley, Gregory S.; Kelson, Daniel D. (2014-06)

We present radial velocities, equivalent widths, model atmosphere parameters, and abundances or upper limits for 53 species of 48 elements derived from high resolution optical spectroscopy of 313 metal-poor stars. A majority ...