Spectrophotometry of the variable emission object HM Sagittae
Spectroscopic observations of HM Sge were carried out in September--December 1976 in the 3600--8000 A range at dispersions of 230 A/mm (slit spectrograms) and 160 A/mm (objective-prism spectra) at H..gamma... The emission lines identified are listed, with their central intensity; for some lines the equivalent width and absolute flux density (erg sec/sup -1/ cm/sup -2/) are given. No significant variations in line intensity occurred during the period of observation. The absolute continuum energy distribution, corrected for interstellar extinction in the direction of HM Sge, is interpreted by a model of a hot star embedded in a dense gaseous nebula. For the best fit to the continuum at lambda=3600--6400 A, the model parameters are T/sub */=50 000 /sup 0/K, T/sub e/=10 000 /sup 0/K (for the envelope), and n/sub e/> or approx. =10/sup 6/ cm/sup -3/. However, at lambda>6400 A the model diverges from the observations, the disparity increasing with lambda, probably because of the infrared excess known to be present in HM Sge. It is an open question whether the system contains a cool component.
- Research Organization:
- Shternberg Astronomical Institute, Moscow
- OSTI ID:
- 5965534
- Journal Information:
- Sov. Astron. AJ (Engl. Transl.); (United States), Journal Name: Sov. Astron. AJ (Engl. Transl.); (United States) Vol. 23:2; ISSN SAAJA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
BALMER LINES
EMISSION SPECTRA
FLUX DENSITY
INTERSTELLAR GRAINS
MATHEMATICAL MODELS
NEBULAE
PARTICLES
SPECTRA
SPECTROPHOTOMETRY
SPECTROSCOPY
STAR EVOLUTION
STAR MODELS
STARS
STELLAR ATMOSPHERES
VARIABLE STARS