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相关论文: Rapid Evolution of the White Dwarf Pulsar AR Scorp…

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We report the discovery of rapid periodic signals in the light curves of two cataclysmic variables with prominent white-dwarf components in their spectra, SDSS J1457+51 and BW Sculptoris. These stars therefore appear to be new members of…

Evolution of a coronal loop in response to an impulsive energy release is numerically modelled. It is shown that the loop density evolution curves exhibit quasi-periodic perturbations with the periods given approximately by the ratio of the…

天体物理学 · 物理学 2009-11-10 V. M. Nakariakov , D. Tsiklauri , A. Kelly , T. D. Arber , M. J. Aschwanden

In the past few decades, observations have revealed signatures of metals polluting the atmospheres of white dwarfs. The diffusion timescale for metals to sink from the atmosphere of a white dwarf is of the order of days for a…

地球与行星天体物理 · 物理学 2018-07-10 Jeremy L. Smallwood , Rebecca G. Martin , Mario Livio , Stephen H. Lubow

We describe results derived from thirty years of observations of PSR B1913+16. Together with the Keplerian orbital parameters, measurements of the relativistic periastron advance and a combination of gravitational redshift and time dilation…

天体物理学 · 物理学 2007-05-23 J. M. Weisberg , J. H. Taylor

We analyse the K2 short cadence data of the intermediate polar FO Aqr and provide accurate and updated orbital and spin periodicities. We additionally find small spin period changes as a function of orbital phase of ~0.02 seconds…

太阳与恒星天体物理 · 物理学 2016-08-17 S. Scaringi , C. Knigge , T. J. Maccarone

We analyze optical photometric data of short term variability (flickering) of accreting white dwarfs in cataclysmic variables (KR Aur, MV Lyr, V794 Aql, TT Ari, V425 Cas), recurrent novae (RS Oph and T CrB) and jet-ejecting symbiotic stars…

太阳与恒星天体物理 · 物理学 2016-04-12 R. K. Zamanov , S. Boeva , G. Latev , J. L. Sokoloski , K. A. Stoyanov , V. Genkov , S. V. Tsvetkova , T. Tomov , A. Antov , M. F. Bode

The magnetic cataclysmic variable AE Aquarii hosts a rapidly rotating white dwarf which is thought to expel most of the material streaming onto it. Observations of AE Aqr have been obtained in the wavelength range of 5 - 70 microns with the…

天体物理学 · 物理学 2011-02-11 G. Dubus , R. E. Taam , C. Hull , D. M. Watson , J. C. Mauerhan

We examine the statistics of main-sequence / main-sequence, main-sequence / white-dwarf and white-dwarf / white-dwarf wide binaries at 10^2.5-10^4 AU separations in Gaia data. For binaries containing a white dwarf, we find a complex…

太阳与恒星天体物理 · 物理学 2025-09-09 Hsiang-Chih Hwang , Nadia Zakamska

Magnetic cataclysmic variables provide a natural laboratory for studying how accretion interacts with compact-object magnetospheres and generates stochastic variability. We present an optical variability study of the intermediate-polar…

In this paper we derive a bound on the rate of change of the gravitational constant G coming from the pulsating white dwarf G117-B15A. This star is a ZZ Ceti pulsator extensively studied with astroseismological techniques for last three…

天体物理学 · 物理学 2009-11-07 Marek Biesiada , Beata Malec

We present a study of the observational properties of Millisecond Pulsars (MSPs) by way of their magnetic fields, spin periods and masses. These measurements are derived through the scenario of Accretion Induced Collapse (AIC) of white…

高能天体物理现象 · 物理学 2015-06-11 A. Taani , Y. H. Zhao , A. Moraghan

The detection of the orbital period of 4.36his reported for the new Intermediate Polar 1 WGA 1958.2+3232. The orbital period was derived from time-resolved photometric and spectral observations. We also confirmed the 733 sec spin period of…

天体物理学 · 物理学 2009-10-31 Sergei. V. Zharikov , Gaghik. H. Tovmassian , Juan Echevarria , Aixa Aube Cardenas;

White dwarf masses in cataclysmic variables are difficult to determine accurately, but are fundamental for understanding binary system parameters, as well as binary evolution. We investigate the X-ray spectral properties of a sample of…

星系天体物理 · 物理学 2009-11-13 Jorg Brunschweiger , Jochen Greiner , Marco Ajello , Julian Osborne

We aim both to complement the existing data on the spin history of the peculiar accreting X-ray pulsar GX 1+4 with more past and current data from BeppoSAX, INTEGRAL, and Fermi and to interpret the evolution in the framework of accretion…

高能天体物理现象 · 物理学 2015-06-03 A. González-Galán , E. Kuulkers , P. Kretschmar , S. Larsson , K. Postnov , A. Kochetkova , M. H. Finger

Recently several long-period radio transients have been discovered, with strongly polarised coherent radio pulses appearing on timescales between tens to thousands of seconds [1,2]. In some cases the radio pulses have been interpreted as…

The measurements of pulsar frequency second derivatives have shown that they are $10^2-10^6$ times larger than expected for standard pulsar spin-down law, and are even negative for about half of pulsars. We explain these paradoxical results…

天体物理学 · 物理学 2008-11-26 A. Biryukov , G. Beskin , S. Karpov

The fine structure and the variations of the optical pulse shape and phase of the Crab pulsar are studied on various time scales. The observations have been carried out on 4-m William Hershel and 6-m BTA telescopes with APD photon counter,…

天体物理学 · 物理学 2008-11-26 S. Karpov , G. Beskin , A. Biryukov , V. Debur , V. Plokhotnichenko , M. Redfern , A. Shearer

How pulsars radiate is a long-standing problem. Detailed polarization measurements of individual pulses shed light on currently unknown emission processes. Recently, based on supersensitive observations, dwarf pulses have been recognized as…

高能天体物理现象 · 物理学 2024-03-19 Yi Yan , J. L. Han , D. J. Zhou , L. Xie , F. F. Kou , P. F. Wang , C. Wang , T. Wang

I argue that the rotation of white dwarfs is not a remnant of the angular momentum of their main sequence progenitors but a result of the mass loss process on the AGB. Weak magnetic fields, if present in stellar interiors, are likely to…

天体物理学 · 物理学 2007-05-23 H. C. Spruit

We present a 7 yr timing study of the 2.5 ms X-ray pulsar SAX J1808.4-3658, an X-ray transient with a recurrence time of ~2 yr, using data from the Rossi X-ray Timing Explorer covering 4 transient outbursts (1998-2005). We verify that the…