A5053994888- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Astrophysics and Star Formation Studies
- Pulsars and Gravitational Waves Research
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- SAS software applications and methods
- Laser-Plasma Interactions and Diagnostics
- High-pressure geophysics and materials
- Astrophysics and Cosmic Phenomena
- Solar and Space Plasma Dynamics
- X-ray Spectroscopy and Fluorescence Analysis
- Radio Astronomy Observations and Technology
- Planetary Science and Exploration
- Geophysics and Gravity Measurements
- Mechanics and Biomechanics Studies
- Advanced X-ray Imaging Techniques
- Spectroscopy and Chemometric Analyses
- Calibration and Measurement Techniques
- Astronomical and nuclear sciences
- Control and Dynamics of Mobile Robots
- Civil and Structural Engineering Research
- Spectroscopy and Laser Applications
Crimean Astrophysical Observatory
2014-2024
Special Astrophysical Observatory
2015-2024
Russian Academy of Sciences
2024
Turku Centre for Computer Science
2016
University of Oulu
2016
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...
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...
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...
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...
ABSTRACT We present results of polarimetric, photometric, and spectral observations the near-Earth asteroid (3200) Phaethon carried out at 6-m BTA telescope Special Astrophysical Observatory 2.6-m 1.25-m telescopes Crimean over a wide range phase angles during its close approach to Earth end 2017 (α = 19°–135°) in 2020 α 52.2°. Using our other available literature data, we found that maximum degree linear polarization V band is Pmax (45 ± 1) per cent angle αmax 124.0° 0.4°, whereas inversion...
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 report on a superoutburst of the AM CVn-type object SDSS J090221.35+381941.9 [J0902; orbital period 0.03355(6) d] in 2014 March-April. The entire outburst consisted precursor and main superoutburst, followed by short rebrightening. During rising branch we detected growing superhumps (stage A superhumps) with 0.03409(1) d. plateau phase shorter B were observed. Using stage superhumps, able to measure dynamical precession rate accretion disk at 3:1 resonance, obtained mass ratio (q)...
Abstract We observed RZ LMi, which is renowned for its extremely short (∼19 d) supercycle and a member of small, unusual class cataclysmic variables called ER UMa-type dwarf novae, in 2013 2016. In 2016, the supercycles this object substantially lengthened comparison to previous measurements 35, 32, 60 d three consecutive superoutbursts. consider that virtually experienced transition nova-like state (permanent superhumper). This behavior reproduced prediction thermal-tidal instability model...
Abstract An analysis of photometric observations the star V647 Her (M3.5V) obtained at 1.25-m telescope Crimean Astrophysical Observatory in 2022 is presented. The presence a low-amplitude variability brightness with period 20.69 d, found from 2019 was confirmed. It shown that as decreases, becomes redder. observed kind due to cool spots on surface and rotational modulation full amplitude no more than 0 $$^{{\text{m}}}_{.}$$ 05. We perform comparison results 2019, 2022, 2004. locations...
We present results of a multi-site photometric campaign on the high-amplitude $δ$\,Scuti star KIC\,6382916 in {\it Kepler} field. The was observed over 85-d interval at five different sites North America and Europe during 2011. photometry ground-based multicolour light curves are used to investigate pulsational content identify principal modes. High-dispersion spectroscopy also obtained order derive stellar parameters projected rotational velocity. From an analysis time series, three...
Abstract We present a photometric study of NY Ser, an in-the-gap SU UMa-type nova, in 2002 and 2013. determined the duration its superoutburst mean period superhump are 18 d 0.10458 d, respectively. detected 2013 that Ser showed two distinct states separated by superoutburst. A state rather infrequent normal outbursts lasted at least 44 before superoutburst, frequent started immediately after 34 d. Unlike typical UMa star with bimodal distribution outburst duration, displayed diversity...
Continuing the project described by Kato et al. (2009, arXiv:0905.1757), we collected times of superhump maxima for 127 SU UMa-type dwarf novae observed mainly during 2016--2017 season and characterized these objects. We provide updated statistics relation between orbital period variation superhumps, variations rebrightening type in WZ Sge-type obtained minimum 0.05290(2)d confirmed presence gap above ~0.09d. note that four objects (NY Her, 1RXS J161659.5+620014, CRTS J033349.8-282244 SDSS...
The bright Nova Cygni 1975 is a rare nova on magnetic white dwarf (WD). Later it was found to be an asynchronous polar, now called V1500 Cyg. Our multisite photometric campaign occurring 40 years post eruption covered 26-nights (2015-2017). reflection effect from the heated donor has decreased, but still dominates op- tical radiation with amplitude ~1^m.5. 0^m.3 residual reveals cyclotron emission and ellipsoidal variations. Mean brightness modulation night-to-night used measure 9.6-d...
Abstract We report on two superoutbursts of the AM CVn-type object CR Boo in 2014 April–March and 2015 May–June. A precursor outburst accompanied both these superoutbursts. During rising branch main superoutburst 2014, we detected growing superhumps (stage superhumps) whose period was 0.017669(24) d. Assuming that this reflects dynamical precession rate at radius 3:1 resonance, could estimate mass ratio (q = M2/M1) 0.101(4) by using stage superhump orbital 0.0170290(6) This is consistent...
Continuing the project described by Kato et al. (2009, PASJ, 61, S395, arXiv/0905.1757), we collected times of superhump maxima for 102 SU UMa-type dwarf novae observed mainly during 2017 season and characterized these objects. WZ Sge-type stars identified in this study are PT And, ASASSN-17ei, ASASSN-17el, ASASSN-17es, ASASSN-17fn, ASASSN-17fz, ASASSN-17hw, ASASSN-17kd, ASASSN-17la, PNV J20205397+2508145 TCP J00332502-3518565. We obtained new mass ratios 7 objects using growing superhumps...