Spectra from classical novae form under highly diverse conditions, i.e., from extremely high to low densities and optical depths, and from violent outflows to more quiescent gas. In addition, novae spectra often show molecular emission and lines from unusual atomic species. Hence observations of classical novae are not only relevant to the study of novae themselves, but provide useful constraints on such diverse topics as line formation in active galaxies and emission line stars. The program here is unique in its ability to measure novae spectra. The novel aspect is the use of a combined optical-IR spectrophotometer that simultaneously measures the entire 0.4-4.8 micron spectrum through the same slit, obviating the need for coordinated observations at separate facilities and eliminating the uncertainties inherent in comparing separate wavelength regions observed at different epochs under different conditions. This provides a unified set of line ratios for those chemical species, whose emission lines appear, over a wide wavelength range. Follow-up measurements of current novae by other observers are spurred by making preliminary results available immediately through IAU circulars and posting quick-look spectra on a website. The spectrometer development and detailed data analysis are provided free to this program. This effort expands on a successful program at Lick Observatory that has provided a significant fraction of the near-infrared nova spectra reported in the refereed astronomical literature during the past decade.
Broader Impact: The investigations of emission line formation processes in novae will benefit studies of other astronomical sources with emission lines. In addition, classical novae are the prime source of certain isotopes in the interstellar medium and are probably very similar in nature to the precursors of type Ia supernovae. Results are published in a timely manner in the astronomical literature. This work fosters collaborations between industrial (Aerospace Corporation) and academic scientists (Universities of California and Minnesota) and involves support of a student in the study of these important objects.
