11 citations · 22 across the 7 of their papers we have counts for
7 papers
A Catalog of Homogeneously Derived Stellar Parameters for Spectroscopic Survey Stars
Stefan Y. Stefanov, Evelina Zaharieva, Djemma Ruseva +9
Uniformly derived stellar parameters are vital for exoplanet demographic studies because they directly influence the inferred planetary masses, radii, and bulk densities. This stud…
Dynamical analysis of the 5:1 mean-motion resonance of the HD 202206 system
Yingyi Cao, Man Hoi Lee, Sabine Reffert +2
The HD 202206 system, which features two substellar companions with a 5:1 period ratio around a solar-type star, offers a rare opportunity to study high-order mean-motion resonance…
A distant brown dwarf coplanar to a warm Jupiter and a hot super-Earth
Matías I. Jones, Luca Naponiello, Trifon Trifonov +21
In transiting planetary systems, in which planetary sizes are accurately determined from transit observations, the presence of transit-timing variations (TTVs), especially when com…
Long-period magnetic activity in the K dwarf GJ 1137 and a new super-Earth on a 9-day orbit
Denitza Stoeva, Atanas K. Stefanov, Stefan Y. Stefanov +12
Aims: We investigate long-term radial velocity (RV) variability in the K-dwarf star GJ 1137 (HD 93083, HIP52521), a known Saturn-mass exoplanet host, and assess the role of stellar…
Optical spectroscopy of Be stars: peak separation of Balmer emission lines
R. K. Zamanov, K. A. Stoyanov, S. Y. Stefanov +2
The Be stars display variable optical emission lines originating in the circumstellar disc. Here we analyse high resolution spectroscopic observations of Be stars and the distance…
Tilted discs in six poorly studied cataclysmic variables
Stefan Y. Stefanov, Atanas K. Stefanov
In this work, we search for negative superhumps (nSHs) in poorly studied cataclysmic variables using TESS data. We find three eclipsing binaries with nSH signatures: HBHA 4204-09,…
Optical spectroscopy of the Be/black hole binary MWC656 -- interaction of a black hole with a circumstellar disc
R. K. Zamanov, K. A. Stoyanov, D. Marchev +7
We present new spectroscopic observations of the Be/black hole binary MWC 656 obtained during the period 2015 - 2021. We measure the equivalent width of H (EW), H (…