QPOS of by CAM in Low and High States

Павленко, Е. П.; Shugarov, S. Yu.; Antipin, S.; Sokolov, D. A.; Borisov, G.; Budzinovskaya, I. A.

doi:10.1007/978-94-009-0325-8_64

Cataclysmic Variables and Related Objects

1996

DOI: 10.1007/978-94-009-0325-8_64

|View full text |Cite

QPOS of by CAM in Low and High States

Е. П. Павленко

S. Yu. Shugarov

S. Antipin

et al.

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...

Citation Types

Supporting

Mentioning

Contrasting

Year Published

2006

2008

Publication Types

Select...

Article3

Relationship

Self Cite2

Independent1

Authors

Journals

Cited by 3 publications

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such long-term and high-amplitude QPOs are not typical for polars. However, earlier, during the high-brightness state of BY Cam, QPOs with a similar typical time (but smaller amplitude) have been observed in the optical and X-ray band by Pavlenko et al [4] and Silber et al [5].…”

mentioning

confidence: 78%

Asynchronous polar BY Cam: periods, quasiperiods, accretion modes and magnetic field structure

Павленко

Babina

Андреев

2007

Astronomical & Astrophysical Transactions

Self Cite

View full text Add to dashboard Cite

The asynchronous polar BY Cam in the low-brightness state displays observational evidence of the quadrupole component magnetic field of a magnetic white dwarf.BY Cam belongs to the subgroup of asynchronous polars. Comprehensive charge-coupled device photometric investigations of this magnetic binary have been carried out in 2004-2005 with a Cassegrain 38 cm telescope (Crimean Astrophysical Observatory) and 60 cm telescope (Terskol). All this time BY Cam was in a low-accretion state.We detected the simultaneous existences of an orbital period (0.1398 day), a spin period (0.1384 day), a side-band period (0.1371 day) and a 14.56 day synodic period [1]. The shape of the spin light curve could have two peaks (mostly) or three peaks (rarer), one peak indicating the accretion that unequally occurs on to two or three magnetic poles. These peaks are located at approximately 0.25 spin phase from each other. The synodic light curve has four peaks and its shape survives over at least 43 synodic cycles [2]. The O − C values of the maxima for the major and secondary accretion spots display a behaviour which strongly depends on the synodic phase: Twice the synodic cycle at phases 0.3 and 0.8, the O − C value for the main peak show jumps for half the spin period. Between these events the O − C value slightly increases and again jumps for a quarter of the spin period at synodic phase 0.55. All these results are observational evidence for the following:(i) a strong variation in the accretion rate which depends on the synodic phase; (ii) a complex structure of the magnetic field of the magnetic white dwarf in the BY Cam binary, thus confirming our earlier suggestion of a dipole+quadrupole-type magnetic field [3];

show abstract

mentioning

confidence: 78%

Asynchronous polar BY Cam: periods, quasiperiods, accretion modes and magnetic field structure

Павленко

Babina

Андреев

2007

Astronomical & Astrophysical Transactions

Self Cite

View full text Add to dashboard Cite

show abstract

Magnetic field structure and accretion regimes of the asynchronous polar by Cam

Павленко

2006

Astrophysics

Self Cite

View full text Add to dashboard Cite

Series of photometric CCD observations of the asynchronous polar BY Cam in a low accretion state (R = 14 m -16 m ) were made on the K-380 telescope at the Crimean Astrophysical Observatory (CrAO) over 100 hours in the course of 31 nights during [2004][2005]. A period of P 1 = 0.137120 ± 0.000002 days was found for the variations in the brightness, along with less significant periods of P 2 = 0.139759 ± 0.000003 and P 3 = 0.138428 ± 0.000002 days, where P 2 and P 3 are obviously the orbital and rotation periods, while the dominant period P 1 is the sideband period. A modulation in the brightness and an amplitude of 0.137 days in the oscillations at the orbital-rotational beat period (synodic cycle) of 14.568 ± 0.003 day are found for the first time. The profile of the modulation period is four humped. This indicates that the magnetic field has a quadrupole component, which shows up well during the low brightness state. Accretion takes place simultaneously into two or three accretion zones, but at different rates. The times of the times of maxima for the main accretion zone vary with the phase of the beat period. Three types of variation of this sort are distinguished: linear, discontinuous, and chaotic, which indicate changes in the accretion regimes. At synodic phases 0.25 and 0.78 the bulk of the stream switches by 180°, and at phase 0.55, by ~75°. At phases of 0.25-0.55 and 0.55-0.78, the O-C shift with a period of 0.1384 days, which can be explained by a retrograde shift of the main accretion zone relative to the magnetic pole and/or a change in the angle between the field lines and the surface of the white dwarf owing to the asynchronous rotation. For phases of 0.78-1.25 the motion of the accretion zone is quite chaotic. It is found that synchronization of the components occurs at a rate of less than dP rot /P rot~1 0 -9 day/day.

show abstract

Idling magnetic white dwarf in the synchronizing polar BY Cam. The Noah-2 project

et al. 2008

View full text Add to dashboard Cite

Abstract:A multi-color study of the variability of the magnetic cataclysmic variable BY Cam is presented. The observations were obtained at the Korean 1.8 m and Ukrainian 2.6 m, 1.2 m and 38 cm telescopes in [2003][2004][2005] 56 observational runs cover 189 hours. The variations of the mean brightness in different colors are correlated with a slope R/ V = 1 29(4), where the number in brackets denotes the error estimates in the last digits. For individual runs, this slope is much smaller ranging from 0.98(3) to 1.24(3), with a mean value of 1.11(1). Near the maximum, the slope becomes smaller for some nights, indicating more "blue" spectral energy distribution, whereas the night-to-night variability has an "infrared" character. For the simultaneous UBVRI photometry, the slopes increase with wavelength from U/ R = 0 23(1) to I/ R = 1 18(1). Such wavelength dependence is the opposite of that observed in non-magnetic cataclysmic variables, in agreement with the model of cyclotron emission. The principal component analysis shows two components of variablitity with different spectral energy distributions (with a third at the limit of detection), which possibly correspond to different regions of emission. The highest peak in the scalegram analysis corresponds to the 200 min spin variability, its quarter and to the 30 min and 8 min QPOs. The amplitudes of these components are dependent on wavelength and luminosity state. The light curves were fitted by a statistically optimal trigonometrical polynomial (up to 4th order) to take into account a 4-hump structure. The dependences of these parameters on the phase of the beat period and on mean brightness are discussed.

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

hi@scite.ai

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

QPOS of by CAM in Low and High States

Cited by 3 publications

References 0 publications

Asynchronous polar BY Cam: periods, quasiperiods, accretion modes and magnetic field structure

Asynchronous polar BY Cam: periods, quasiperiods, accretion modes and magnetic field structure

Magnetic field structure and accretion regimes of the asynchronous polar by Cam

Idling magnetic white dwarf in the synchronizing polar BY Cam. The Noah-2 project

Contact Info

Product

Resources

About