55 citations · 212 across the 29 of their papers we have counts for
31 papers
Central stars of newly discovered infrared nebulae: eruptive Be stars PY Gem and HD253659
Olga Maryeva, Julieta Sánchez Arias, Sergey Karpov +3
The presence of a nebula around massive hot stars often works as an indicator that the object is either in an advanced evolutionary stage or a rare product of close binary interact…
An Halpha survey of infrared bow-shocks around OB-type stars
Kuljeet Singh Saddal, Michaela Kraus, Dieter H. Nickeler +3
Bow shocks (BSs) around massive stars are commonly identified in mid-infrared (MIR) surveys. In contrast, systematic optical investigations of these structures remain scarce with o…
M dwarfs quasi-periodic pulsations at a time resolution of 1 s
Alexander Panferov, Grigory Beskin, Sergey Karpov +1
Quasi-periodic pulsations (QPPs) of Sun and stars are challenging for stellar flare models. The white light stellar QPPs in the periodicity region of tens of second are unexplored…
Wolf-Rayet stars -- what we know and what we don't
Olga Maryeva
Today, we have a sufficiently complete picture of what the Wolf--Rayet (WR) stars are. Predictions of stellar evolution theory are in a good agreement with their parameters, estima…
An IXPE-Led X-ray Spectro-Polarimetric Campaign on the Soft State of Cygnus X-1: X-ray Polarimetric Evidence for Strong Gravitational Lensing
James F. Steiner, Edward Nathan, Kun Hu +134
We present the first X-ray spectropolarimetric results for Cygnus X-1 in its soft state from a campaign of five IXPE observations conducted during 2023 May-June. Companion multiwav…
LAMOST J040901.83+329355.6 -- a new Galactic star with Wolf--Rayet characteristics on a post-AGB to CSPN transitional stage
Olga Maryeva, Aynur Abdulkarimova, Sergey Karpov +2
The similarity in physical conditions in winds of low-mass post-asymptotic giant branch stars and evolved massive stars leads to the appearance of an interesting phenomenon of spec…
Revealing the Binarity of HD 36030 -- One of the Hottest Flare Stars
Olga Maryeva, Péter Németh, Sergey Karpov
The Kepler and TESS space missions significantly expanded our knowledge of what types of stars display flaring activity by recording a vast amount of super-flares from solar-like s…
Unveiling the nitrogen-rich massive star in the metal-poor galaxy NGC 4068
Anastasiya D. Yarovova, Oleg V. Egorov, Alexei V. Moiseev +1
We report the identification of the unusual emission-line stellar-like object in the nearby low-metallicity (Z ~ 0.1Zsun) dwarf galaxy NGC 4068. Our observations performed with lon…
How long can LBVs sleep? A long-term photometric vaiability and spectral study of the Galactic candidate luminous blue variable MN112
Olga Maryeva, Sergey Karpov, Alexei Kniazev +1
Luminous Blue Variables (LBVs) are massive stars that show strong spectral and photometric variability. The question of what evolutionary stages they represent and what exactly dri…
Revisiting the evolved hypergiants in the Magellanic Clouds
Michalis Kourniotis, Michaela Kraus, Olga Maryeva +2
The massive stars that survive the phase of red supergiants (RSGs) spend the rest of their life in extremity. Their unstable atmospheres facilitate the formation and episodic eject…
Wray 15-906: a candidate luminous blue variable discovered with WISE, Herschel and SALT
O. V. Maryeva, V. V. Gvaramadze, A. Y. Kniazev +1
We present the results of study of the Galactic candidate luminous blue variable Wray 15-906, revealed via detection of its infrared circumstellar shell (of \approx2 pc in diameter…
Asymmetrical nebula of the M33 variable GR290 (WR/LBV)
Olga V. Maryeva, Gloria Koenigsberger, Sergey V. Karpov +5
Context: GR290 (M33 V0532=Romano's star) is a luminous M33 object undergoing photometric variability typical for luminous blue variable (LBV) stars. It lies inside Wolf-Rayet regio…
The History Goes On: Century Long Study of Romano's Star
Olga Maryeva, Roberto F. Viotti, Gloria Koenigsberger +3
GR 290 (M 33 V0532 = Romano's Star) is a unique variable star in the M33 galaxy, which simultaneously displays variability typical for luminous blue variable (LBV) stars and physic…
A massive white-dwarf merger product before final collapse
V. V. Gvaramadze, G. Gräfener, N. Langer +4
Gravitational wave emission can lead to the coalescence of close pairs of compact objects orbiting each other. For the case of neutron stars such mergers may yield masses above the…
CPD-64 2731: a massive spun-up and rejuvenated high-velocity runaway star
V. V. Gvaramadze, O. V. Maryeva, A. Y. Kniazev +4
We report the results of our study of the high-velocity (\approx160 km/s) runaway O star CPD-64 2731 and its associated horseshoe-shaped nebula discovered with the Wide-field Infra…
Wind and nebula of the M33 variable GR290 (WR/LBV)
Olga Maryeva, Gloria Koenigsberger, Oleg Egorov +4
Context: GR290 (M33/V532=Romano's Star) is a suspected post-LBV star located in M33 galaxy that shows a rare Wolf-Rayet spectrum during its minimum light phase. In spite of many st…
Optical spectroscopy of the blue supergiant Sk-69 279 and its circumstellar shell with SALT
V. V. Gvaramadze, A. Y. Kniazev, O. V. Maryeva +1
We report the results of optical spectroscopy of the blue supergiant Sk-69 279 and its circular shell in the Large Magellanic Cloud (LMC) with the Southern African Large Telescope…
On the nature of anomalous reddening of Cygnus OB2 #12 hypergiant
O. V. Maryeva, E. L. Chentsov, V. P. Goranskij +2
To explain the nature of the anomalously high reddening (Av~10 mag) towards one of the most luminous stars in the Galaxy - Cyg OB2 #12 (B5 Ia-0), also known as MT304, we carried ou…
The study of massive stars with 50 Msun initial mass at different evolutionary stages
Olga Maryeva
We will present results of studies of several massive stars at different evolutionary stages, but with similar values of the initial mass: O-supergiants belonging to association Cy…
GR 290 (Romano's Star): 2. Light history and evolutionary state
V. F. Polcaro, O. Maryeva, R. Nesci +11
We have built the historical light curve of the luminous variable GR 290 back to 1901, from old observations of the star found in several archival plates of M 33. These old recordi…
On the nature of high reddening of Cygnus OB2 #12 hypergiant
O. V. Maryeva, E. L. Chentsov, V. P. Goranskij +4
To explain the nature of the high reddening (Av~10 mag) towards one of the most luminous stars in the Galaxy - Cyg OB2 #12 (B5 Ia-0), also known as MT304, we carried out spectro-ph…
Properties of dwarf stars in Cygnus OB2
O. V. Maryeva, S. Yu. Parfenov, M. V. Yushkin +2
We present the results of investigation of five stars, originally classified as dwarfs, belonging to Cyg OB2 association, their stellar and wind properties. Using both TLUSTY and C…
The half-century history of studies of Romano's star
Olga Maryeva
Luminous blue variables (LBVs) are rare objects of very high luminosity and mass loss rates, low wind velocities, exhibiting strong irregular photometric and spectral variability.…
Investigation of CygOB2 #11 (O5 Ifc) by modeling its atmosphere
Olga Maryeva, Roman Zhuchkov, Eugene Malogolovets
We continue the study of O-supergiants belonging to the association Cyg OB2 using moderate-resolution spectra. In this paper we present results of the modeling of the stellar atmos…