منابع مشابه
Ultraviolet Observations of Supernovae
The motivations to make ultraviolet (UV) studies of supernovae (SNe) are reviewed and discussed in the light of the results obtained so far by means of IUE and HST observations. It appears that UV studies of SNe can, and do lead to fundamental results not only for our understanding of the SN phenomenon, such as the kinematics and the metallicity of the ejecta, but also for exciting new findings...
متن کاملUltraviolet Observations of NGC 3516 using the Hopkins Ultraviolet Telescope
We observed the Seyfert 1 galaxy NGC 3516 twice during the flight of Astro-2 using the Hopkins Ultraviolet Telescope aboard the space shuttle Endeavour in March 1995. Simultaneous X-ray observations were performed with ASCA. Our far-ultraviolet spectra cover the spectral range 820–1840 Å with a resolution of 2–4 Å. No significant variations were found between the two observations. The total spe...
متن کاملX - ray observations of 4 Draconis : symbiotic binary or cataclysmic triple ?
We present the first X-ray observations of the 4 Draconis system, consisting of an M3 III giant with a hot ultraviolet companion. It has been claimed that the companion is itself an AM Her-type binary system, an identification that places strong constraints on the evolution of cataclysmic variables. We find that the X-ray properties of 4 Draconis are consistent with the presence of an accreting...
متن کاملSpectral observations of AG Draconis during quiescence and outburst ( 1993 – 1995 )
High and intermediate resolution observations of the blue and the Hα spectral regions of the symbiotic star AG Dra at quiescence and during an active phase in 1994 and 1995 were performed. Variations of profiles, fluxes and radial velocity data of a number of emission lines are investigated. The width (FWHM) of all of these lines was very large at times close to the 1994 light maximum. The emis...
متن کاملThe metallicity of CM Draconis
We compare observations of the eclipsing binary system CM Draconis (hereafter CM Dra) with synthetic spectra computed using the stellar atmosphere code PHOENIX. High-resolution infrared spectroscopic observations of six 0.05-mm-wide regions between 1.51 and 2.45mm, combined with previous work, particularly CM Dra’s accurately known surface gravity, enable us to estimate its metallicity using de...
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ژورنال
عنوان ژورنال: International Astronomical Union Colloquium
سال: 1987
ISSN: 0252-9211
DOI: 10.1017/s0252921100116574