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The high velocity symbiotic star AG Draconis after its 1980 outburstHigh and low resolution spectra of AG Dra taken in 1981 are analyzed. The UV spectrum of AG Dra is characterized by prominent high ionization emission lines superimposed on a strong continuum. At high resolution, several intense absorption lines of interstellar origin are seen, in spite of the low interstellar extinction. A similar situation is displayed by the high galactic latitude sd0 stars. The radial velocity difference between the emission lines and the i.s. lines is about -105 Km/sec in agreement with the optical observations. The He II 1640 A line appears much stronger than in other symbiotic stars and suggests the presence of a hot source which is variable according to the activity of the star. The line also exhibits broad emission wings which could be formed in a rotating disk. The NV resonance doublet displays a P Cygni profile and is probably formed in a warm wind. Two components in the UV continuum are identified: a steep component dominating the far UV probably associated with the hot source, and a flatter continuum in the near UV which cannot be accounted for by f-f and f-b emission alone, but which is probably emitted by an optically thick region or disk.
Document ID
19820023361
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Viotti, R.
(Consiglio Nazionale delle Ricerche Frascati, Italy)
Altamore, A.
(Rome Univ. Rome, United States)
Baratta, G. B.
(Osservatorio Astronomico Villafranca, Spain)
Cassatella, A.
(ESA Paris, United States)
Friedjung, M.
(Inst. d'Astrophysique Frascati, Italy)
Giangrande, A.
(Consiglio Nazionale delle Ricerche Munich, United States)
Ponz, D.
(European Southern Observatory Frascati, Italy)
Ricciardi, O.
(Consiglio Nazionale delle Ricerche)
Date Acquired
August 10, 2013
Publication Date
January 1, 1982
Publication Information
Publication: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.
Subject Category
Astronomy
Accession Number
82N31237
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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