A5013739430- Astrophysical Phenomena and Observations
- Stellar, planetary, and galactic studies
- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- High-pressure geophysics and materials
- Astro and Planetary Science
- Astrophysics and Cosmic Phenomena
- Geophysics and Gravity Measurements
- SAS software applications and methods
- Solar and Space Plasma Dynamics
- Mechanics and Biomechanics Studies
- Galaxies: Formation, Evolution, Phenomena
- Particle Accelerators and Free-Electron Lasers
- Calibration and Measurement Techniques
- Geomagnetism and Paleomagnetism Studies
- Atomic and Subatomic Physics Research
- History and Developments in Astronomy
- Metallurgy and Material Forming
- Inertial Sensor and Navigation
- Industrial Engineering and Technologies
- Advanced X-ray and CT Imaging
- Laser-Plasma Interactions and Diagnostics
Universidad Nacional Autónoma de México
2016-2025
Al-Farabi Kazakh National University
2021-2024
Special Astrophysical Observatory
1996-2023
Universidad Autónoma de Baja California
2013-2023
Ensenada Institute of Technology
2000-2020
Institute of Mining
2020
Mining Institute of the Ural Branch of the Russian Academy of Sciences
2019
University of Southampton
2018
Instituto de Geofísica y Astronomía
2001-2010
We report Hubble Space Telescope imaging, obtained 155 and 449 days after the 2006 outburst of recurrent nova RS Ophiuchi, together with ground-based spectroscopic observations, from Observatorio Astron\'omico Nacional en San Pedro M\'artir, Baja California, M\'exico at Astrof\'isico Guillermo Haro, Cananea, Sonora, M\'exico. The observations first epoch were used as inputs to model geometry kinematic structure evolving Oph nebular remnant. find that modeled remnant comprises two distinct...
The black hole (BH) candidate SWIFT J1753.5-0127 has remained active since the onset of its 2005 outburst. Emission lines in optical spectrum were observed at very beginning outburst, but then been featureless making a precise BH mass estimation impossible. Here we present results from our and UV observations taken 2012-2013. Our new show extremely broad, double-peaked emission spectra. data also narrow absorption features with nearly synchronous significant Doppler motions. A radial...
Continuing the project described by Kato et al. (2009, arXiv:0905.1757), we collected times of superhump maxima for 102 SU UMa-type dwarf novae observed mainly during 2014-2015 season and characterized these objects. Our has greatly improved statistics distribution orbital periods, which is a good approximation cataclysmic variables at terminal evolutionary stage, confirmed presence period minimum 0.053 d spike just above this period. The number density monotonically decreased toward longer...
Prompted by peculiar spectroscopic variability observed in SDSS/APOGEE $H$-band spectra, we monitored the Be star HD 55606 using optical spectroscopy and found that it is an exotic double-lined binary (SB2) consisting of a hot, compact companion probably OB subdwarf (sdOB) star. Motion sdOB traced its impact on strong He~I lines, as radial velocity ($V_{r}$) variable, double-peaked emission profiles with narrow central absorption cores. Weak He II 4686 {\AA} associated detected most spectra....
AS 314 (V452 Sct) is a poorly studied early-type emission-line star, which exhibits an infrared excess at wavelengths longer than 10 μm. Its earlier studies have been limited to small amounts of observational data and led controversial conclusions about its fundamental parameters evolutionary status. Comparison high-resolution spectra taken over 20 years ago with those Luminous Blue Variables other high-luminosity objects suggested observed properties can be explained by strong stellar wind...
We report the recent results of a long-term spectroscopic and photometric monitoring IRAS 17449+2320, member least studied group objects with B[e] phenomenon called FS CMa-type objects. The main hypothesis for explaining strong emission-line spectra infrared excesses these assumes an ongoing or past mass transfer between components in binary systems. object is only star gaseous dusty envelope, where variable magnetic field (5.5–7.2 kG) was found through splitting some spectral lines....
In this study, we present refined orbital and fundamental parameters of the Galactic B[e] supergiant binary system HD 327083 using Bayesian Markov Chain Monte Carlo (MCMC) method applied to radial velocities data 327083. We found that is well described by a circular model with mass ratio components q=1.15±0.07. modeled evolutionary history MESA code. Initially, was formed period Porb=108 day, which contained stars 13.00 ±0.05 M⊙ 11.50±0.05 masses. They had relatively slow rotation...
MWC 342 (V1972 Cyg) was discovered nearly 90 years ago as an early-type emission-line star. It among the first hot stars whose strong infrared excess detected in early 1970s. Several mostly short-term photometric and spectroscopic studies resulted contradictory conclusions about nature evolutionary status of 342. has been classified a pre-main-sequence Herbig Be star, evolved suspected binary system, long-period variable Suggestions on secondary component to this B0/B1 primary included cool...
We report extensive 3-yr multiwavelength observations of the WZ Sge-type dwarf nova SSS J122221.7−311525 during its unusual double superoutburst, following decline and in quiescence. The second segment superoutburst had a long duration 33 d very gentle with rate 0.02 mag d−1, it displayed an extended post-outburst lasting at least 500 d. Simultaneously start rapid fading from plateau, system showed appearance strong near-infrared excess resulting red colours, which reached extreme values (B...
Cataclysmic variables (CVs) are close binary systems in which the primary, more massive star, is a white dwarf. CVs usually exhibit number of periodicities, most now understood. However, recently new phenomenon was discovered that does not fit standard picture. Two objects have been found to show periods much longer than orbital and no relation it, either light curves or radial velocity variations measured from spectroscopy. Here we precession fast-rotating magnetically accreting dwarf can...
This study of SDSS0804 is primarily concerned with the double-hump shape in light curve and its connection accretion disk this bounce-back system. Time-resolved photometric spectroscopic observations were obtained to analyze behavior system between superoutbursts. A geometric model a binary containing two outer annuli spiral density waves was applied explain Doppler tomography. Observations carried out during 2008-2009, after object's magnitude decreased V~17.7(0.1) from March 2006 eruption....
We present the results of broad-band photometry nearby middle-aged radio pulsar PSR B0656+14 and its neighborhood obtained with 6-meter telescope SAO RAS Hubble Space Telescope. The spectral flux decreases increasing frequency in near-IR range increases near-UV range. increase towards UV can be naturally interpreted as Rayleigh-Jeans tail soft thermal component X-ray spectrum emitted from surface cooling neutron star. Continuation power-law component, which dominates high-energy spectrum, to...
FS CMa stars form a group of objects with the B[e] phenomenon that were previously known as unclassified or warm dust (B[e]WD) until recently. They exhibit strong emission-line spectra and IR excesses, most likely due to recently formed circumstellar dust. These properties have been suggested be ongoing recent rapid mass exchange in binary systems hot primaries various types secondaries. The first paper this series reported an analysis available information about Galactic phenomenon, initial...
We present infrared JHK photometry of the cataclysmic variable (CV) SDSS J123813.73 − 033933.0 and analyze it along with optical spectroscopy, demonstrating that binary system is most probably comprised a massive white dwarf Teff = 12000 ± 1000 K brown spectral type L4. The inferred parameters suggest this may have evolved beyond orbital period minimum bounce-back system. stands out among CVs by exhibiting cyclical variability Zharikov et al. called brightenings. These are not related to...
Aims. The work is aimed at studying the circumstellar disk of bright classical binary Be star π Aqr.
New time-resolved optical spectroscopic echelle observations of the nova-like cataclysmic variable RW Sextantis were obtained, with aim studying properties emission features in system. The profile H α line can be clearly divided into two ('narrow' and 'wide') components. Similar profiles are observed another system, 1RXS J064434.5+33445, for which we also reanalysed spectral data redetermined system parameters. source 'narrow', low-velocity component is irradiated face secondary star. We...
Based on XMM--Newton X-ray observations IGR J19552+0044 appears to be either a pre-polar or an asynchronous polar. We conducted follow-up optical identify the sources and periods of variability precisely classify this source correctly. Extensive multicolor photometric medium- high-resolution spectroscopy were performed period search codes applied sort out complex object. found firm evidence discording spectroscopic (81.29+/-0.01m) (83.599+/-0.002m) that we ascribe white dwarf (WD)\ spin...
High-dispersion time-resolved spectroscopy of the unique magnetic cataclysmic variable AE Aqr is presented. A radial velocity analysis absorption lines yields K2= 168.7 ± 1 km s−1. Substantial deviations curve from a sinusoid are interpreted in terms intensity variations over secondary star's surface. complex rotational as function orbital phase detected which has modulation frequency twice frequency, leading to an estimate binary inclination angle that close 70°. The minimum and maximum...
Abstract We report the results of spectroscopic and photometric observations emission-line object AS 386. For first time we found that it exhibits B[e] phenomenon fits definition an FS CMa type object. The optical spectrum shows presence a B-type star with following properties: T eff = 11,000 ± 500 K, log L / ⊙ 3.7 0.3, mass 7 1 M , distance D 2.4 0.3 kpc from Sun. detected regular radial velocity variations both absorption emission lines orbital parameters: P orb =131.27 0.09 days,...
We report the results of a long-term spectroscopic monitoring FS CMa type object MWC 728. found that it is binary system with B5 ve ( = 14,000 ± 1000 K) primary and G8 iii 5000 secondary. Absorption line positions secondary vary, semi-amplitude ∼20 km s−1 period 27.5 days. The system's mass function 2.3 × 10−2 , its orbital plane ∼13°–15° tilted from sky. primary's s−1, combined this tilt, implies rotates at nearly breakup velocity. detected strong variations Balmer He i emission-line...
ABSTRACT We obtained photometric observations of the nova-like (NL) cataclysmic variable RW Tri and gathered all available AAVSO other data from literature. determined system parameters found their uncertainties using code developed by us to model light curves binary systems. New time-resolved optical spectroscopic were also study properties emission features produced system. The usual interpretation single-peaked lines in NL systems is related bi-conical wind accretion disc’s inner part....