Analysis of Co-spatial UV-optical STIS Spectra of Planetary Nebula NGC
  3242
  This project sought to consider two important aspects of the planetary nebula
NGC 3242 using new long-slit HST/STIS spectra. First, we investigated whether
this object is chemically homogeneous by dividing the slit into different
regions spatially and calculating the abundances of each region. The major
result is that the elements of He, C, O, and Ne are chemically homogeneous
within uncertainties across the regions probed, implying that the stellar
outflow was well-mixed. Second, we constrained the stellar properties using
photoionization models computed by CLOUDY and tested the effects of three
different density profiles on these parameters. The three profiles tested were
a constant density profile, a Gaussian density profile, and a Gaussian with a
power law density profile. The temperature and luminosity were not affected
significantly by the choice of density structure. The values for the stellar
temperature and luminosity from our best fit model are 89.7$^{+7.3}_{-4.7}$kK
and log(L/Lsol)=3.36$^{+0.28}_{-0.22}$, respectively. Comparing to evolutionary
models on an HR diagram, this corresponds to an initial and final mass of
0.95$^{+0.35}_{-0.09}$ Msol and 0.56$^{+0.01}_{-0.01}$ Msol, respectively.
