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相关论文: On X-ray Variability in Active Binary Stars

200 篇论文

A comprehensive review of aperiodic rapid X-ray variability (QPO and noise) in X-ray binaries with neutron stars and black holes.

天体物理学 · 物理学 2007-05-23 M. van der Klis

We present a $\approx 11.5$ year adaptive optics (AO) study of stellar variability and search for eclipsing binaries in the central $\sim 0.4$ pc ($\sim 10''$) of the Milky Way nuclear star cluster. We measure the photometry of 563 stars…

The number of binary asteroids in the near-Earth region might be significantly higher than expected. While Bottke and Melosh (1996) suggested that about 15% of the NEAs are binaries, as indicated from the frequency of double craters, and…

天体物理学 · 物理学 2007-05-23 David Polishook , Noah Brosch

Irradiance variability has been monitored from space for more than two decades. Even if data are coming from different sources, it is well established that a temporal variability exists which can be set to as approximately 0.1%, in phase…

天体物理学 · 物理学 2009-11-11 J. P. Rozelot , S. Lefebvre , S. Pireaux , A. Ajabshirizadeh

Solar quasi-biennial oscillations with period range 0.6 to 4 years, are prominent in records of solar activity. Here we show that the 1.6 year quasi-biennial oscillation in solar activity has the exceptional feature of phase inversion…

太阳与恒星天体物理 · 物理学 2021-10-27 Ian R. Edmonds

Variability is a general property of active galactic nuclei (AGN). At X-rays, the way in which these changes occur is not yet clear. In the particular case of low ionisation nuclear emission line region (LINER) nuclei, variations on…

高能天体物理现象 · 物理学 2014-09-17 L. Hernández-García , O. González-Martín , J. Masegosa , I. Márquez

We present X-ray light curves of Cygnus X-3 as measured by the recently launched AstroSat satellite. The light curve folded over the binary period of 4.8 hours shows a remarkable stability over the past 45 years and we find that we can use…

Gravitational waves at suitable frequencies can resonantly interact with a binary system, inducing changes to its orbit. A stochastic gravitational-wave background causes the orbital elements of the binary to execute a classic random walk,…

广义相对论与量子宇宙学 · 物理学 2013-05-27 Lam Hui , Sean T. McWilliams , I-Sheng Yang

We apply probabilistic generative modelling of colour-magnitude diagrams to six young Galactic open star clusters and determine their mass functions, binary mass-ratio distributions, and the frequencies of binary stars. We find that younger…

星系天体物理 · 物理学 2024-11-26 Jason Alexander , Michael Albrow

We present results of a photometric CCD study of the incidence of microvariability in the optical emission of a sample of 20 blazars detected at gamma-ray energies by the EGRET instrument of the Compton Gamma-Ray Observatory. We have…

天体物理学 · 物理学 2009-11-07 G. E. Romero , S. A. Cellone , J. A. Combi , I. Andruchow

By combining ground-based spectrographic observations of variability in the chromospheric emission from Sun-like stars with the variability seen in their eigenmode frequencies, it is possible to relate the changes observed at the surfaces…

太阳与恒星天体物理 · 物理学 2019-03-27 C. Karoff , T. S. Metcalfe , B. T. Montet , N. E. Jannsen , A. R. G. Santos , M. B. Nielsen , W. J. Chaplin

We present optical lightcurves of 428 periodic variable stars coincident with ROSAT X-ray sources, detected using the first run of the SuperWASP photometric survey. Only 68 of these were previously recognised as periodic variables. A…

The Wilson approximate dynamics and the Einstein dynamics are compared for binary systems. At the second post-Newtonian approximation, genuine two-body aspects are found to differ by up to 114\%. In the regime of a formal innermost stable…

广义相对论与量子宇宙学 · 物理学 2019-08-15 R. Rieth , G. Schäfer

To confirm faint Be/X-ray binary candidates from the XMM-Newton survey of the Small Magellanic Cloud, we searched for X-ray outbursts in archival ROSAT observations. We found that RXJ0123.4-7321 was much brighter when detected with ROSAT…

高能天体物理现象 · 物理学 2016-08-31 R. Sturm , F. Haberl , W. Pietsch , A. Udalski

The reflection of X-ray radiation produced near a compact object from its stellar companion contributes to the orbital variability of polarization in X-ray binaries. The X-rays are reflected mainly via Thomson scattering resulting in a high…

高能天体物理现象 · 物理学 2024-08-28 Varpu Ahlberg , Vadim Kravtsov , Juri Poutanen

A sample of spectroscopic binaries and a sample of single planetary systems, both having main-sequence solar-type primary components, are selected in order to compare their eccentricities. The positions of the objects in the…

天体物理学 · 物理学 2009-11-10 J. L. Halbwachs , M. Mayor , S. Udry

The bulk of available stellar activity observations is frequently checked for the manifestation of signs in comparison with the known characteristic of solar magnetic modulation. The problem is that stellar activity records are usually an…

太阳与恒星天体物理 · 物理学 2020-06-03 R. Stepanov , N. I. Bondar' , M. M. Katsova , D. Sokoloff , P. Frick

X-ray binaries are binary star systems in which a compact object (a neutron star or a black hole) and a relatively normal star orbit a common centre of mass. Since the discovery of X-ray binaries with the first X-ray telescopes in the…

天体物理学 · 物理学 2008-02-07 David Russell

We analyze X-ray light curves of the blazars Mrk 421, PKS 2155-304, and 3C 273 using observations by the Soft X-ray Telescope on board AstroSat and archival XMM-Newton data. We use light curves of length 30-90 ks each from 3-4 epochs for…

高能天体物理现象 · 物理学 2023-10-27 Joy Bhattacharyya , Ritesh Ghosh , Ritaban Chatterjee , Nabanita Das

We present higher-order multiplicity results for 60 solar-type spectroscopic binaries based on 0.75 micron imaging data taken by the Robotic Adaptive Optics system (Robo-AO) at the Kitt Peak 2.1m telescope. Our contrast curves show…

太阳与恒星天体物理 · 物理学 2024-10-29 Emily Laos , Keivan G. Stassun , Robert D. Mathieu