108 citations · 320 across the 9 of their papers we have counts for
9 papers
Independent Emission and Absorption Abundances for Planetary Nebulae
Robert Williams, Edward B. Jenkins, Jack A. Baldwin +4
Emission-line abundances have been uncertain for more than a decade due to unexplained discrepancies in the relative intensities of the forbidden lines and weak permitted recombina…
s-Process Abundances in Planetary Nebulae
Brian Sharpee, Yong Zhang, Robert Williams +5
The s-process should occur in all but the lower mass progenitor stars of planetary nebulae, and this should be reflected in the chemical composition of the gas which is expelled to…
Abundances of s-process elements in planetary nebulae: Br, Kr & Xe
Y. Zhang, R. Williams, E. Pellegrini +5
We identify emission lines of post-iron peak elements in very high signal-to-noise spectra of a sample of planetary nebulae. Analysis of lines from ions of Kr and Xe reveals enhanc…
Identification and Characterization of Faint Emission Lines in the Spectrum of the Planetary Nebula IC 418
Brian Sharpee, Jack A. Baldwin, Robert Williams
We present high signal-to-noise echelle spectra of the compact high surface brightness, low ionization planetary nebula IC 418. These reveal 807 emission lines down to intensities…
The Changing Blazhko Effect of XZ Cygni
Aaron LaCluyze, Horace A. Smith, E. -M. Gill +9
New CCD photometry has been obtained for the RR Lyrae variable star XZ Cygni. An analysis of old and new photometry confirms earlier results that XZ Cygni exhibits the Blazhko Effe…
Measurements of the Singly Ionized Oxygen Auroral Doublet Lines 7320,7330ÅUsing High Resolution Sky Spectra
Brian D. Sharpee, Tom G. Slanger, David L. Huestis +1
The wavelengths of the individual [O II] 2s22p3 2Do(5/2) - 2s22p3 2Po(1/2,3/2) 7320Åand [O II] 2s22p3 2Do(3/2) - 2s22p3 2Po(1/2,3/2) 7330Åauroral doublet component lines have been…