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Journal of Physical Studies 16(3), Article 3903 [7 pages] (2012)
DOI: https://doi.org/10.30970/jps.16.3903 SPECTRUM OF YELLOW HYPERGIANT ρ CAS DURING 2007-2011V. G. Klochkova1, I. A. Usenko2
1Special Astronomical Observatory Russian Academy
of Sciences, |
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Multiple observations carried out during 2007-2011 using high-resolution spectroscopy with 6\,m telescope BTA SAO RAS allowed to search for the peculiar properties of optical and UV spectra and field of velocities in the yellow hypergiant's $ρ $\,Cas atmosphere. Radial velocity determined by symmetrical absorptions of metals varies in time relatively to the system's velocity $V_{\rm sys}=-47\pm1$\,\kms, and this fact is a sequence of small amplitude pulsations of the near-photospherical atmosphere layers. In the single moments the velocity gradient in the deep layers of stellar atmosphere have been observed. Radial velocity determined using by short-wave components of Ba\,{\rm II}, Sr\,{\rm II}, Ti\,{\rm II} and other strong lines with low level excitational potential takes place in the narrow limit of $V_{\rm blue}\sim -60\div-70$\,\kms. We suppose that short-wave components form in the circumstellar shell as well as one of the components of sodium doublet lines D Na\,{\rm I}.
PACS number(s): 95.75.Fg, 95.85.Kr, 97.10.Ex, 97.30.Gj