Correlation Between Nitrogen and Oxygen Content in Planetary Nebulae Morphology

Abstract

Planetary nebulae are the result of stars’ deaths and are beautiful cosmic spectacles. All planetary nebulae form in the same manner and from similar stars. Despite these facts, planetary nebulae form into many different shapes (morphologies) as the clouds of gas expand into space. The purpose of this experiment was to determine what may be one cause of the many different morphologies. Possible causes relate to the composition of the nebulae or possibly the temperature or size of the progenitor star that created it. Our hypothesis was that if the visible light spectra (3500-7000Å) of a sample of planetary nebulae of two different morphologies (polar and spherical) are taken and analyzed, then the spherical nebulae would contain more Oxygen, and the polar nebulae would contain more Nitrogen. This hypothesis is based off the behavior of these two gases when exposed to a magnetic field, which is produced by planetary nebulae. The spectral data was acquired using the B&C Visible Light Spectrometer, and this data was reduced and analyzed by Imaging Reduction and Analysis Facility software. After the data was reduced, the wavelength of each spectral line was measured, and the percent composition of the light emitted from each nebula was determined. When the %composition of the two gases, Oxygen and Nitrogen, were compared between the two groups of planetary nebulae, the results appeared to support the hypothesis. The polar group averaged 16.6% more nitrogen than the spherical group, and averaged 17.8% less oxygen. Based on this, it appears as if the amount of these two gases in a planetary nebula may affect the shape it takes as it forms and interacts with magnetic fields.