Е. П. Павленко
A5011444396- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Stellar, planetary, and galactic studies
- Pulsars and Gravitational Waves Research
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astrophysics and Cosmic Phenomena
- High-pressure geophysics and materials
- SAS software applications and methods
- Solar and Space Plasma Dynamics
- Particle Accelerators and Free-Electron Lasers
- Astro and Planetary Science
- Laser-Plasma Interactions and Diagnostics
- Mechanics and Biomechanics Studies
- Geophysics and Gravity Measurements
- X-ray Spectroscopy and Fluorescence Analysis
- History and Developments in Astronomy
- Historical Astronomy and Related Studies
- Calibration and Measurement Techniques
- Superconducting Materials and Applications
- Advanced X-ray Imaging Techniques
- Spacecraft Design and Technology
- Adaptive optics and wavefront sensing
- Spacecraft and Cryogenic Technologies
Crimean Astrophysical Observatory
2015-2024
Special Astrophysical Observatory
1990-2024
University of Cambridge
2022-2023
V.I. Vernadsky Crimean Federal University
2017-2021
Research Institute of Agriculture of Crimea
1978-2018
Turku Centre for Computer Science
2016
University of Oulu
2016
Federal Research Centre of Nutrition and Biotechnology
2016
Kyoto University
2014
Institute of Applied Astronomy
2010
We have gathered optical photometry data from the literature on a large sample of Swift-era gamma-ray burst (GRB) afterglows including GRBs up to September 2009, for total 76 GRBs, and present an additional three pre-Swift not included in earlier sample. Furthermore, we publish 840 new points 42 GRB afterglows, sets 050319, 050408, 050802, 050820A, 050922C, 060418, 080413A 080810. analyzed light curves all derived spectral energy distributions with best quality, allowing us estimate host...
Abstract We systematically surveyed period variations of superhumps in SU UMa-type dwarf novae based on newly obtained data and past publications. In many systems, the evolution superhump is found to be composed three distinct stages: an early evolutionary stage with a longer period, middle varying periods, final shorter, stable period. During stage, systems periods less than 0.08 d show positive derivatives. present observational characteristics these stages give greatly improved...
Aims.We present a study of the optical and near-infrared (NIR) properties Type Ia Supernova (SN Ia) 2003du.
Abstract Molecular vibrations couple to visible light only weakly, have small mutual interactions, and hence are often ignored for non-linear optics. Here we show the extreme confinement provided by plasmonic nano- pico-cavities can sufficiently enhance optomechanical coupling so that intense laser illumination drastically softens molecular bonds. This pumping regime produces strong distortions of Raman vibrational spectrum related giant frequency shifts from an optical spring effect which...
Abstract Continued from Kato et al. (2009, PASJ, 61, S395), we collected the times of superhump maxima for 68 SU UMa-type dwarf novae, mainly observed during 2009–2010 season. The newly obtained data confirmed basic findings reported in (ibid.): presence stages A–C and predominance positive period derivatives stage B systems with periods shorter than 0.07 d. There was a systematic difference longer 0.075 d between this study (ibid.). We suggest that possibly caused by relative lack...
Continuing the project described by Kato et al. (2009, arXiv:0905.1757), we studied 86 SU UMa-type dwarf novae. We confirmed general trends such as relation between period derivatives and orbital periods. There are some systems showing positive despite long observed 2011 outburst of WZ Sge-type nova BW Scl, recorded an O-C diagram similar to those previously known The OT J184228.1+483742 showed unusual pattern double outbursts composed with early superhumps one ordinary superhumps. propose...
We report the results of a worldwide campaign to observe WZ Sagittae during its 2001 superoutburst. After 23 yr slumber at V = 15.5, star rose within 2 days peak brightness 8.2, and showed main eruption lasting 25 days. The return quiescence was punctuated by 12 small eruptions, ∼1 mag amplitude day recurrence time; these "echo outbursts" are uncertain origin, but somewhat resemble normal outbursts dwarf novae. 52 days, began slow decline quiescence.
view Abstract Citations (129) References (13) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Discovery and Observations by WATCH of the X-Ray Transient GRS 1915+105 Castro-Tirado, Alberto J. ; Brandt, Soren Lund, Niels Lapshov, Igor Sunyaev, Rashid A. Shlyapnikov, Aleksei Guziy, Sergei Pavlenko, Elena P. The X-ray transient was discovered on 1992 August 15 all sky monitor GRANAT. source is located in Galactic plane. initial light curve presented, as well...
Abstract Continuing the project described by Kato et al. (2009, PASJ, 61, S395), we collected times of superhump maxima for 51 SU UMa-type dwarf novae, mainly observed during 2010–2011 season. Although most new data systems with short periods basically confirmed findings (ibid.) and (2010, 62, 1525), long-period system GX Cas showed an exceptionally large positive-period derivative. An analysis public Kepler V344 Lyr V1504 Cyg yielded less-striking stage transitions. In Lyr, there was a...
The spectral and photometric studies of the cataclysmic variable Gaia 19cwm (or ZTF19aamkwxk) have been performed. Based on analysis long-term variability, it is concluded that object belongs to WZ Sge type stars. light curves show eclipses recurring with an orbital period $86.32048 \pm 0.00005$ min, as well out-of-eclipse variability a $\approx 6.45$ min. latter stable for $\sim 4$ years appears correspond rotation magnetic white dwarf, i.e., intermediate polar. spectra photospheric lines...
We present new results from the analysis of 55 high-resolution spectra V404 Cyg (the optical counterpart X-ray transient GS 2023 + 338) taken in 1991 July–August which, added to our 1990 July Hα spectra, establish most complete spectroscopic data base quiescence this black hole candidate. In addition, we multicolour (optical and infrared) white-light photometry, latter being partially simultaneous with spectroscopy.
Continuing the project described by Kato et al. (2009a, arXiv:0905.1757), we collected times of superhump maxima for SU UMa-type dwarf novae mainly observed during 2012-2013 season. We found three objects (V444 Peg, CSS J203937 and MASTER J212624) having strongly positive period derivatives despite long orbital (Porb). By using growing stage (stage A) superhumps, obtained mass ratios six objects. characterized nine new WZ Sge-type novae. made a pilot survey decline rate slowly fading part...
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...
Abstract Continuing the project described by Kato et al. (2009, PASJ, 61, S395), we collected times of superhump maxima for 128 SU UMa-type dwarf novae observed mainly during 2015–2016 season and characterized these objects. The data have improved distribution orbital periods, relation between period variation superhumps, variations rebrightening type in WZ Sge-type Coupled with new measurements mass ratios using growing stages now a clearer statistically greatly evolutionary path near...
We report precise measures of the orbital and superhump period in twenty more dwarf novae. For ten stars, we new confirmed spectroscopic periods - signifying P_o as well P_sh. These are GX Cas, HO Del, HS Vir, BC UMa, RZ Leo, KV Dra, KS TU Crt, QW Ser, Sge. remaining ten, a medley P_sh measurements from photometry; most new, with some confirmations previous values. And, LL WX Cet, MM Hya, AO Oct, V2051 Oph, NY KK Tel, HV RX J1155.4-5641. Periods, usual, can be measured to high accuracy,...
We report on a discovery of "negative" superhumps during the 2011 January superoutburst ER UMa. During which started 16, we detected negative having period 0.062242(9) d, shorter than orbital by 2.2%. No evidence positive was this observation. This finding indicates that disk exhibited retrograde precession superoutburst, contrary to all other known cases superoutbursts. The duration those ordinary superoutbursts and intervals normal outbursts were longer ones. suggest possibility such...
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...
We carried out the photometric observations of SU UMa-type dwarf nova ER UMa during 2011 and 2012, which showed existence persistent negative superhumps even superoutburst. performed two-dimensional period analysis its light curves by using a method called "least absolute shrinkage selection operator" (Lasso) "phase dispersion minimization" (PDM) analysis, we found that systematically changed between superoutburst next The trend change can beinterpreted as reflecting disk radius. This radius...
Optical spectroscopy of the X-ray transient, GS2000 + 25, during its 1988 outburst shows that this system is similar to A0620 – 00, but at a greater distance ( > 2 kpc). We present photometry from La Palma and Russia reveal ~ 0.1-mag modulation period 8.33 hr which we associated with orbital period. propose modulation, in form ‘hump’ light curve, analogous mechanism an eccentric, precessing accretion disc used by Whitehurst (1988) account for superhumps SU UMa systems. If confirmed, would...
Abstract Continuing the project undertaken by Kato et al. (2009), we collected times of superhump maxima for 56 SU UMa-type dwarf novae mainly observed during 2013–2014 season and characterized these objects. We detected negative superhumps in VW Hyi indicated that low number normal outbursts some supercycles can be interpreted as a result disk tilt. This finding, combined with Kepler observation V1504 Cyg V344 Lyr, suggests tilt is responsible modulating outburst pattern novae. also studied...
We observed the 2015 July-August long outburst of V1006 Cyg and established this object to be an SU UMa-type dwarf nova in period gap. Our observations have confirmed that is second showing three types outbursts (normal, normal superoutbursts) after TU Men. succeeded recording growing stage superhumps (stage A superhumps) obtained a mass ratio 0.26-0.33, which close stability limit tidal instability. This identification demonstrated indeed slowly grow systems near limit, idea first...