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A 2-D model for the O'Connell effect in W Ursae Majoris systems /
(1999)
The light curves of W Ursae Majoris stars often show asymmetries which are called the O'Connell Effect. Traditionally, these asymmetries were measured by calculating the magnitude difference of the peak intensity at each ...
The abundance and chemical evolution of nitrogen in spiral galaxies.
(1998)
The character of nitrogen processing in spiral galaxies is studied in this dissertation. Of particular interest are questions of how the (N/O) ratio changes over time as a result of perturbations of environmental parameters, ...
Prospecting for elements: Galactic halo planetary nebulae abundances and Virgo spiral galaxy color profiles.
(1998)
Near-infrared Virgo cluster spiral colors. Near-infrared (NIR) surface photometry in J (1.2$\mu$m), H (1.6$\mu$m) and K (2.2$\mu$m) have been obtained for a sample of Virgo cluster spirals; NGC4321, NGC4303, NGC4571, ...
Non-local thermodynamic equilibrium spectrum synthesis of type Ia supernovae.
(1997)
This thesis is broken down into 4 major sections, each highlighting a different way with which to use spectrum synthesis to analyze SNe Ia. Chapters 2 and 3 look at normal SNe Ia and their potential use as distance indicators ...
Abundances in planetary nebulae: An autopsy of low and intermediate mass stars.
(1997)
In this work we report on the results of synthetic thermally pulsing asymptotic giant branch models (TP-AGB) and compare the results to the abundance ratios in a sample of planetary nebulae. We use updated the input ...
Heavenly metal: A study of neutron-capture element abundances in metal-poor galactic halo stars.
(1998)
New abundances for neutron-capture elements in a large sample of metal-poor giants from the Bond survey in addition to 3 well known individual cases, are presented. The spectra for the Bond Giants were acquired with the ...
"'Tis something, nothing", a search for radio supernovae.
(1998)
We report VLA radio observations of 29 SNe with ages ranging from 10 days to about 90 years past explosion. Included are detections of known radio SNe 1950B, 1957D, 1970G, 1983N, the suspected radio SN 1923A, and the ...