Search Publications
U Energy Distribution of AZ Cassiopeiae
Kang, Young-Woon
The IUE low dispersion spectra of AZ Cas have been analyzed for line identifications and energy distribution in ultraviolet region. Highly ionized atoms, Si IV and C IV are identified. We could infer a temperature range of the B star between 15,000K and 20,000K. The energy density distribution shows a hump between IUE short wavelength and long wav…
Determination of Wind Parameters by the Method of Differential Corrections
Kim, You-Kyung; Kang, Young Woon
This paper describes a method for the determination of wind parameters as mass-loss rate, wind velocity, stochastic velocity in Zeta Aurigae type binaries. We have modified the Baade's (1989) computer code to analyze the wind parameters of Zeta Aurigae type binaries according to the least squares criterion. The modified program adjusts the wind pa…
Ultraviolet Spectrophotometry of VV Cephei
Kang, Young Woon
The IUE archival spectra of VV Cephei were collected to investigate the eclipse nature in the ultraviolet. The temperature of the B star has been determined, as approximately 30000K, based on the flux distributions during egress. Light curves of VV Cephei were reduced from the spectrophotometry of the IUE archival spectra. Three light curves at th…
M ¥± Line Variation of 32 Cygni
Kang, Young Woon
The Mg ¥± lines have been extracted from the IUE archival spectra of 32 Cygni to investigate the effect of the atmospheric eclipse. The UV light curve has been reduced from the continuum flux at the center wavelength of 2807.5 Å in the IUE spectra. The equivalent width of the Mg ¥± k absoption line has been measured for each spectra. The results o…
IUE Archival Spectra of 31 Cygni
Kang, Young Woon
UV light curve of 31 Cygni has been made from the IUE high dispersion spectra. The depth of primary minimum of the light curve is 5.2 magnitudes because the B4 star's steep spectral gradient. The light curve has been analyzed by the method of Wilson and Devinney Differential Correction(WD). The radial velocities have been measured using the Mg ¥± …
Ultraviolet Flux Variation of Epsilon Aurigae
Kang, Young Woon
The eighteen ultraviolet light curves of Epsilon Aurigae have been plotted using the integrated fluxes reduced from the 233 IUE low dispersion spectra taken between 1978 and 1986. The times of contacts and depth of eclipse have been determined from the light curves at the wavelength from 2550 Å to 3050 Å. The UV light curves show two brightenings …
Ground-Based and On-Satellite Observations of BE and B Stars
Jeong, Jang-Hae
Gamma Cassiopeae has been observed at Yonsei University Observatory(YUO) for 31 nights in the period 1983-1987 and a total of 312 UBV observations(104 in each colour) was secured. Light curves of ¥ã Cas in V, B-V, and U-B have been constructed with YUO data; among them we present selected light curves of 5 different long nights. Discussed are the …