199 citations · 1.8k across the 86 of their papers we have counts for
87 papers
The Outbursting YSOs Catalogue (OYCAT)
C. Contreras Peña, J. -E. Lee, G. Herczeg +39
YSOs can display unpredictable and high-amplitude rises in brightness that can last from a few months to possibly over 100 years. These types of outbursts are explained by large ch…
Photometry with the new 1.5-meter telescope of the Rozhen Observatory
E. Semkov, N. Petrov, M. Minev +6
The new 1.5~m telescope (AZ1500) is operating at the National Astronomical Observatory Rozhen, Bulgaria. This paper gives an overview of the telescope and presents a snapshot of th…
Photometric monitoring of PMS stars with the telescopes at Rozhen Observatory
Evgeni Semkov, Sunay Ibryamov, Stoyanka Peneva +1
For several decades we have been performing photometric monitoring of some of the star formation regions. Significant place in our program take observations of objects of the type…
Pre-main sequence stars
Evgeni Semkov
The dissertation presents result from study of Pre-main sequence (PMS) stars that are in the earliest stages of stellar evolution. These young stellar objects are still in the proc…
Study of the long-term photometric variability of eight PMS stars in the young open cluster Trumpler 37
Sunay Ibryamov, Gabriela Zidarova, Evgeni Semkov +1
This paper reports results from our long-term photometric CCD observations of eight pre-main-sequence stars collected from June 2008 to October 2022. These stars are l…
Intra-night optical flux and polarization variability of BL~Lacertae during its 2020 2021 high state
Rumen Bachev, Tushar Tripathi, Alok C. Gupta +15
In this work, we report the presence of rapid intra-night optical variations in both -- flux and polarization of the blazar BL Lacertae during its unprecedented 2020--2021 high sta…