Abstract. We present a new catalogue of symbiotic stars. In our list we include 188 symbiotic stars as well as 30 objects suspected of being symbiotic. For each star, we present basic observational material: coordinates, V and K magnitudes, ultraviolet (UV), infrared (IR), X-ray and radio observations. We also list the spectral type of the cool component, the maximum ionization potential observed, references to finding charts, spectra, classifications and recent papers discussing the physical parameters and nature of each object. Moreover, we present the orbital photometric ephemerides and orbital elements of known symbiotic binaries, pulsational periods for symbiotic Miras, Hipparcos parallaxes and information about outbursts and flickering.
Aims. The aims of our study are to improve the orbital elements of the giant and to derive the spectroscopic orbit for the white dwarf companion of the symbiotic system RS Oph. Spectral variations related to the 2006 outburst are also studied. Methods. We performed an analysis of about seventy optical and near infrared spectra of RS Oph that were acquired between 1998 and June 2008. The spectroscopic orbits were obtained by measuring the radial velocities of the cool component absorption lines and the broad Hα emission wings, which seem to be associated with the hot component. A set of cF-type absorption lines were also analyzed for a possible connection with the hot component motion. We also confirm the presence of the Li I doublet in RS Oph and its radial velocities fit very well to the M-giant radial velocity curve. Regardless of the mechanism involved to produce lithium, its origin is most likely from within the cool giant rather than material captured by the giant at the time of the nova explosion. The quiescent spectra reveal a correlation of the H I and He I emission line fluxes with the monochromatic magnitudes at 4800 Å, indicating that the hot component activity is responsible for those flux variations. We also discuss the spectral characteristics around 54-55 and 240 days after the 2006 outburst. In April 2006 most of the emission lines present a broad pedestal with a strong and narrow component at about −20 km s −1 and two other extended emission components at −200 and +150 km s −1 . These components could originate in a bipolar gas outflow supporting the model of a bipolar shock-heated shell expanding through the cool component wind perpendicularly to the binary orbital plane. Our observations also indicate that the cF absorption system was disrupted during the outburst, and restored about 240 days after the outburst, which is consistent with the resumption of accretion.
Context. Besides the astrometric mission of the Gaia satellite, its repeated and high-precision measurements also serve as an all-sky photometric transient survey. The sudden brightenings of the sources are published as Gaia Photometric Science Alerts and are made publicly available, allowing the community to photometrically and spectroscopically follow up on the object. Aims. The goal of this paper is to analyze the nature and derive the basic parameters of Gaia18aen, a transient detected at the beginning of 2018. This object coincides with the position of the emission-line star WRAY 15-136. The brightening was classified as a “nova?” on the basis of a subsequent spectroscopic observation. Methods. We analyzed two spectra of Gaia18aen and collected the available photometry of the object covering the brightenings in 2018 and also the preceding and following periods of quiescence. Based on this observational data, we derived the parameters of Gaia18aen and discussed the nature of the object. Results. Gaia18aen is the first symbiotic star discovered by Gaia satellite. The system is an S-type symbiotic star and consists of an M giant of a slightly super-solar metallicity, where Teff ∼ 3500 K, a radius of ∼230 R⊙, and a high luminosity L ∼ 7400 L⊙. The hot component is a hot white dwarf. We tentatively determined the orbital period of the system ∼487 d. The main outburst of Gaia18aen in 2018 was accompanied by a decrease in the temperature of the hot component. The first phase of the outburst was characterized by the high luminosity L ∼ 27 000 L⊙, which remained constant for about three weeks after the optical maximum, later followed by the gradual decline of luminosity and increase of temperature. Several re-brightenings have been detected on the timescales of hundreds of days.
We present and discuss a hundred year history of activity of the hot component of RX Pup based on optical photometry and spectroscopy. The outburst evolution of RX Pup resembles that of other symbiotic novae whereas at quiescence the hot component shows activity (high and low activity states) resembling that of symbiotic recurrent novae T CrB and RS Oph.Comment: To appear in in M. Hernanz, J. Jose, eds, Classical Novae Explosions, AIP; 5 pages, 2 figure
Abstract. Preliminary results of the ongoing search for symbiotic binary stars in the Local Group of Galaxies are presented and discussed.
Aims. Relative and absolute emission line shifts have been previously found for symbiotic binaries, but their cause was not clear. This work aims to better understand the emission line shifts. Methods. Positions of strong emission lines were measured on archival UV spectra of Z And, AG Dra, RW Hya, SY Mus and AX Per and relative shifts between the lines of different ions compared. Profiles of lines of RW Hya and Z And were also examined.Results. The reality of the relative shift between resonance and intercombination lines of several times ionised atoms was clearly shown except for AG Dra. This redshift shows a well defined variation with orbital phase for Z And and RW Hya. In addition the intercombination lines from more ionised atoms and especially O iv are redshifted with respect to those from less ionised atoms.Other effects are seen in the profiles. Conclusions. The resonance-intercombination line shift variation can be explained in quiescence by P Cygni shorter wavelength component absorption, due to the wind of the cool component, which is specially strong in inferior conjunction of this cool giant. The velocity stratification permits absorption of line emission. The relative intercombination line shifts may be connected with varying occultation of line emission near an accretion disk, which is optically thick in the continuum.
We have found on six occasions in 1985 and 1986 strong, resolved, components of [O ill] at velocity displacements of ± 150 to 200 km s -1 from the central component whose velocity is similar to that of many lines of various degrees of ionization. A similar component was probably present in 1982. Extensive velocity data are presented and Ha profiles at five phases of the 964-day cycle are displayed. The data are discussed in terms of a bipolar flow either in the plane of the orbit or perpendicular to the orbital plane of a symbiotic binary system.
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