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V. Vujcic

Publications and source records attributed to V. Vujcic.

3 recordsLinked to original sources

Alertissimo -- a tool for orchestration of LSST broker streams

The Vera C. Rubin Observatory, through its Legacy Survey of Space and Time, will soon start producing 10 million alerts on transient astronomical objects per night. Due to logistics and bandwidth, alerts will not be dispatched directly to the public but to 'brokers' i.e. tools selected by LSST to handle alert streams. Brokers offer both common, specific and micro-specific functionalities related to alert handling, analysis, representation and dissemination. In this ecosystem, potentially augmented by data streams from other astronomical sources, there is a - need demonstrated by the community - for use cases which combine features of individual brokers. In this paper we present initial efforts and a prototype of such a tool, along with a language that would allow users to define use cases / workflows in a manner tailored for the domain.

astro-ph.IM

Luminosity class of the symbiotic stars 4U1954+319 and ZZ CMi

We performed optical photometry and spectral observations of the symbiotic stars 4U1954+319 and ZZ CMi. For 4U1954+319 using high-resolution spectra we measure the equivalent widths of diffuse interstellar bands and estimate the interstellar reddening E(B-V)=0.83 +/- 0.09. Using GAIA distances and our photometry, we find (1) absolute V band magnitude of 4U1954+319 M_V=-5.23 +/- 0.08 and that the mass donor is a supergiant of luminosity class Ib, and (2) for ZZ CMi M_V=-0.27 +/- 0.2 and that the mass donor is a giant of luminosity class III.

astro-ph.SR

Astrophysical and laboratory plasmas: HF properties under extreme conditions

The values of electrical conductivity of plasma of stars with a magnetic field or moving in the magnetic field of the other component in a binary system could be of significant interest, since they are useful for the study of thermal evolution of such objects, cooling, nuclear burning of accreted matter, and the investigation of their magnetic fields. So, on the basis of numerically calculated values for the dense plasma conductivity in an external HF electric field, we determine the HF characteristics of astrophysical plasmas under extreme conditions. The examined range of frequencies covers the IR, visible and near UV regions and consider electronic number density and temperature are in the ranges of $10^{21} \textrm{cm}^{-3} \le Ne$ and 20 000 $\le T$, respectively. The method developed here represents a powerful tool for research into white dwarfs with different atmospheric compositions (DA, DC etc.), and for investigation of some other stars (M-type red dwarfs, Sun etc.).

physics.plasm-ph