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A nova is a rapid brightening of a star usually occurring in a period of a few days. The brightening is typically 10 to 12 magnitudes.  It rises to a peak level within a few and then decays to a level usually brighter than its original level over a period of several hundred days.  Most novas occur in close binary systems and are associated with the white dwarf companion.  The mechanism is thought to be the flow of hydrogen from the companion star to the white dwarf.  The hydrogen serves as a new source of fuel for the dwarf.  When a sufficient amount of hydrogen is accumulated it ignites explosively and ejects most of the reacted material into space.  The ejected material is will have elements formed by the thermonuclear reactions as well as residual hydrogen.  The American Association of Variable Star Observers (AAVSO) maintains a web site that publishes information on novas supernovas and other variable stars.  If you wish AAVSO will send you bulletins by e-mail on newly discovered variables.  Another site that will e-mail you alerts is VSNET. 

On December 1, Alfredo Pereira discovered the bright nova Aquilae 99 #2 also known as V1494 Aquilae.  A story of his discovery and background information on the nova can be found at it's reference page on VSNET.  The nova was quite bright reaching a peak magnitude of approximately 4 on December 2 and then slowly decaying.  By December 17 the magnitude had dropped to 6.6.  A detailed light curve is available from the VSNET reference page.  Several spectra were obtained of this nova using the SGS.  Each spectra was taken with an exposure of 600 seconds, processed to remove dark current and calibrated using a neon source.   Spectra were obtained on December 4,7,11,12, and 15.  Graphs of the spectra were produced by Microsoft Excel using the tables from Spectra.  The graphs are presented sequentially below.

A high resolution spectra was obtained on December 4 and processed using Visual Spectra.

The higher resolution shows a secondary peak on the short wavelength side of the H-Alpha peak which is not apparent on the lower resolution spectra.  An enlargement of the central region of the graph shows the details of the H-Alpha region.