Hopkins Ultraviolet Telescope Observations of Nova Circini 1995 and Nova Aquilae 1995
Abstract
We observed Nova Cir 1995 and Nova Aql 1995 with the Hopkins Ultraviolet Telescope during the Astro-2 space shuttle mission in 1995 March. The spectra cover the wavelength range from 820 to 1840 A with a spectral resolution of about 3 A, extending the ultraviolet wavelength coverage of novae to the region between Ly alpha and the Lyman limit for the first time. The Nova Cir spectrum contains many broad carbon, nitrogen, and oxygen emission lines thoughout the HUT wavelength range. We approximate its extinction, and fit absorption by the Lyman and Werner bands of molecular hydrogen to find an H2 column density of log N(H2) = 20.7 cm-2. We calculate electron temperatures and abundances in the nova shell. The abundances are substantially nonsolar. The broad asymmetric line profiles in the Nova Aql spectrum show that this nova has not evolved as quickly as Nova Cir. The Nova Aql spectrum is significantly reddened, with little flux detected below Ly alpha . A series of three spectra taken over 10 days shows dramatic changes in the ultraviolet line strengths and profiles as the shell evolves.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 1995
- DOI:
- 10.1086/309767
- Bibcode:
- 1995ApJ...454L..43G
- Keywords:
-
- STARS: NOVAE;
- STARS: INDIVIDUAL CONSTELLATION NAME: NOVA CIRCINI 1995;
- STARS: INDIVIDUAL CONSTELLATION NAME: NOVA AQUILAE 1995