Symbiotic stars and atmospheric eclipsing binaries
Main researcher
: KOTNIK-KARUZA, DUBRAVKA (48086) Assistants
JURDANA-ŠEPIĆ, RAJKA (170374)
Type of research: basic Duration from: 01/01/91. to 12/31/93. Papers on project (total): 23
Papers on project quoted in Current Contents: 2
Institution name: Pedagoški fakultet, Rijeka (9) Department/Institute: Physics department, Faculty of education, University of Rijeka Address: Omladinska 14, 51000 Rijeka City: 51000 - Rijeka, Croatia
Communication
Phone: 385 (0) 51 516322
Fax: 385 (0) 51 515142
E-mail: kotnik@mapef.pefri.hr
Phone: 385 (0) 51 227474
Phone: 385 (0) 51 516322,227474
Summary: Systematic observation and spectral analysis of symbiotic
stars for long periods of time in the optical and ultraviolet spectral
region help in understanding the reason of their variability and
outbursts at irregular time intervals.The results of the measurements of
radial velocities,line profiles and line intensities can be used to
construct theoretical models in order to explain the physical phenomena
which are the origin of the observed variability. The symbiotic star CH
Cygni has been taken as a representative in such investigations. We have
analysed the high resolution spectra taken at the French National
Observatory in Haute Provence and reduced using the programs avaliable
at the ASTRONET pole of Trieste. The observations which extend over
the last quiescent period of the star are of great interest since they
are unique and unrepeatable and therefore important to understand the
behaviour of such unpredictable objects. Besides, this quiescent phase
appears to be short and the previous interoutburst periods have not been
investigated. Our spectroscopic studies lead to a more complete radial
velocity curve and confirm the binary model of this symbiotic variable.
The monitoring of the time development of some physical parameters, line
profiles and molecular bands in the quiescent phase lead to the
explanation of the atmospheric structure and processes during this
period as well as to the discovery of the signs of a new outburst.
Research goals: The aim of this research was to continue the
observations of the symbiotic star CH Cygni in order to understand the
reasons of its variability and outbursts as well as to derive reliable
orbital data and theoretical model. This star has been observed
systematically since 1965. in the optical and since 1978. also in the
ultraviolet spectral region. Three outbursts have been recorded at
irregular time intervals with a pronounced symbiotic character of the
spectrum, while the interoutburst intervals have not been investigated.
This work deals with one of the quiescent phases of the star in the period
1987-1989 which follows the longest spectroscopically observed activity
phase. The optical spectra have been analysed in order to establish the
structure and processes in the stellar atmosphere and to reveal the signs
and possible reason of outbursts. Besides, extending the observations over
a larger period provides more data for building a suitable model of the
star and to derive reliable orbital parameters.
COOPERATION - INSTITUTIONS
Name of institution
: Universita degli Studi di Trieste
Dipartimento di Astronomia Trieste Italia Type of institution: University/Faculty Type of cooperation: Systematic exchange of information City: 34131 - Trst (I), Italija
Name of institution
: Opservatorij Hvar Geodetskog fakulteta u
Zagrebu Type of institution: University/Faculty Type of cooperation: Occasional exchange of information City: 10000 - Zagreb, Croatia Other information about the project.