Search Publications
Global parameters of the W UMa binaries NSVS 3777464, NSVS 5810460 and ASAS J212236+0657.3
Petrov, N.; Kjurkchieva, D.; Popov, V. +1 more
Photometric observations in Sloan filters g', i' of the short-period eclipsing stars NSVS 3777464, NSVS 5810460 and ASAS J212236+0657.3 are presented. Their goal was determination of the targets' parameters by light curve solutions. We found the three targets to be overcontact binaries of W subtype: NSVS 3777464 and NSVS 5810460 undergo partial ec…
On the flux saturation of SOHO/ERNE proton events
Miteva, Rositsa; Dechev, Momchil; Samwel, Susan W. +1 more
This study lists the main procedures completed on the analysis of solar proton events using data from the SOHO/ERNE high energy detector in the period 1996$-$2017. The highest possible temporal resolution of 1 minute is used here. The proton fluxes from the two analyzed energy channels, at $\sim$25 and $\sim$50 MeV, are compared with the respectiv…
Kinematical structure of open clusters within 1 kpc by Gaia
Elsanhoury, W. H.
The work is based on proper motions, radial velocities, and absolute magnitudes of 56 open clusters located within 1 kpc. We classify those as a function of their distances into five groups (Freedman and Diaconis's rule) as well as a double frequency table may be achieved. For these groups, we calculated their velocity ellipsoid parameters VEPs, e…
Gaia DR2 and Serbian-Bulgarian investigations
Damljanović, Goran
On April $25^{th}$ 2018, the second release of the Gaia catalog (DR2) appeared. It is based on 640 days of Gaia satellite observations; GAIA means Global Astrometric Interferometer for Astrophysics. The observing period was August $22^{nd}$ 2014 - May $23^{rd}$ 2016 (1.75 yr or 21 months with some interruptions). The reference epoch is J2015.5 . T…
High-resolution optical spectroscopy of Nova V392 Per
Stoyanov, K. A.; Georgiev, S.; Stateva, I. +1 more
Here we analyze high-resolution spectra of the Nova V392 Per obtained during the 2018 outburst. The Hα and Hβ emission lines show a triple-peak structure with radial velocities of about -2000 km/s, -250 km/s and 1900 km/s respectively. The near infrared spectrum is dominated by the narrow and single-peaked Paschen lines of hydrogen and the O I λ84…
Comparison of photometric results between the Serbian and Bulgarian telescopes and activities in line with Gaia Alerts (Gaia-FUN-TO)
Damljanović, Goran; Cvetković, Zorica; Pavlović, Rade +5 more
We established the cooperation "Serbian-Bulgarian mini-network telescopes" in 2013, as well as two SANU-BAN joint research projects ("Observations of ICRF radio-sources visible in optical domain" during 2014-2016, and "Study of ICRF radio-sources and fast variable astronomical objects" for the period 2017-2019). Here, some main results of that coo…