Symbiotic variables are strongly interacting systems, in which physical mechanisms related to transfer and accretion of matter cause observable activity. Usually, these systems consist of a cool giant of spectral type K-M and a hot compact star, mostly a white dwarf. The mass transfer most likely takes place from the stellar wind of a cool giant, which is also the source of a dense circumbinary envelope. Both the light curves and the spectra of these objects are complex because several sources and mechanisms contribute to them. The investigation of these systems requires long-term monitoring as symbiotic systems are detached binaries with orbital periods of hundreds to thousands of days. These systems are also interesting from the evolutionary point of view as they may be one of the progenitors of type Ia supernovae.
The New Online Database of Symbiotic Variables is not only a catalog of data for all known symbiotic systems with consistent references but also a web-portal for easy access to this information. The database is available online, allowing the addition of new objects as soon as they are discovered, and add or update data when available. In this way, up-to-date lists of symbiotic variables and information about particular objects can be available to the community at any time.
The database contains data about the position of the objects, their brightness in different spectral regions and bands and other observational properties (e. g. presence of outbursts, flickering, detectable X-ray or radio emission, symbiotic type), orbital properties (orbital period, orbital ephemeris, presence of eclipses, etc.) and parameters of the binary components (their spectral types, effective temperatures, masses, radii, luminosities, presence of pulsations, etc.).
The data of symbiotic variables are presented in the form of tables, which can be explored directly through the web-portal or can be downloaded and used offline in different formats (csv, xlsx, txt, and pdf). Moreover, for all symbiotic binaries included in the database, we have prepared their object pages covering all available information, references, and notes. The object pages contain also links to the portals of SIMBAD, CDS, and VSX. In the near future, we plan to add direct links to the measurements of individual symbiotic variables obtained from sky surveys such as OGLE, MACHO and ASAS-SN.
The aim of the web-portal is not only to provide the researchers information about a specific symbiotic binary or a group of objects but also to serve observers, professional or amateur, who are looking for the information they need to plan their observation programs.
The database is divided into two main parts according to the location of symbiotic variables. The first part consists of extragalactic symbiotic systems which are located in 14 galaxies (LMC, SMC, Draco Dwarf, IC 10, M31, M33, M81, M87, NGC 55, NGC 185, NGC 205, NGC 300, NGC 6822, Willman 1). The second part of the database, consisting of more than 400 galactic objects will be fully released later this year.