Abstract:
Using observed and published spectra in the optical region, we have studied a handful of
novae and symbiotic stars that show novae-like variability in the quiescence phase. We present
results for the novae T Coronae Borealis, GK Persei, RS Ophiuchi, V3890 Sagittarii and V745
Scorpii, and for a symbiotic star BX Monocerotis. Observations were carried out at the 2-m
Himalayan Chandra Telescope (HCT). Generally, the spectra show prominent low-ionization
emission features of hydrogen, helium, iron and oxygen and TiO absorption features resulting
from the cool secondary component; T Coronae Borealis and GK Persei show higher ionization
lines. We used the photoionization code
CLOUDY
to model these spectra. From the best-fitting
models, we have estimated the physical parameters (e.g. temperature, luminosity and hydrogen
density), the elemental abundances and other parameters related to the system. By matching
the spectra of various giants with the absorption features and using the best fit, we have
determined the types of secondaries and also their contribution to the spectra
