相关论文: Rapid multiperiodic variability in a high-mass X-r…

On MJD 56590-1 (2013 Oct 25-26) observations of the Magellanic Clouds by the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) observatory discovered a previously-unreported bright, flaring X-ray source. This source was initially…

Long period variables, among them Miras, are thought to be pulsating. Under this approach the whole star inflates and deflates along a period that can vary from 100 to 900 days; that pulsation is assumed to produce shock waves on the outer…

We find that the emission line object OGLEJ005039.05-725751.4, a member of the cluster OGLE-CL SMC 64, exhibits a peculiar light curve pattern repeating with a recurrence time of 141.45 days. The light curve resembles periodic outbursts…

We have analysed the photometry of 924 type II Cepheids from the Galactic bulge observed by the Optical Gravitational Lensing Experiment. Our goal was to detect and analyse various dynamical phenomena, including, e.g. multi-mode pulsation,…

The final aim of this paper is to expand the sparse group of X-ray binaries with gamma-ray counterparts as laboratories to study high-energy processes under physical conditions that periodically repeat. A follow-up of a candidate system has…

X-rays trace accretion onto compact objects in binaries with low mass companions at rates ranging up to near Eddington. Accretion at high rates onto neutron stars goes through cycles with time-scales of days to months. At lower average…

The bifurcation period in low-mass X-ray binaries is the initial orbital pe- riod which separates the formation of converging systems (which evolve with decreasing orbital periods until the donor becomes degenerate) from the diverging…

Be stars possess gaseous circumstellar disks that modify in many ways the spectrum of the central B star. Furthermore, they exhibit variability at several timescales and for a large number of observables. Putting the pieces together of this…

This paper describes a practical model for the polarization of Be stars which can be used to estimate roughly the physical parameters for optically thin circumstellar envelopes from broadband UBVRI photopolarimetry data. Analysis of…

Graham et al. found a sample of active galactic nuclei (AGNs) and quasars from the Catalina Real-time Transient Survey (CRTS) that have long-term periodic variations in optical continuum, the nature of the periodicity remains uncertain. We…

The high-mass X-ray binary RX J0146.9+6121, with optical counterpart LS I+61 235 (V831 Cas), is an intriguing system on the outskirts of the open cluster NGC 663. It contains the slowest X-ray pulsar known with a pulse period of around…

Aims: We present accurate photometric time series of two Be stars: NW Ser and V1446 Aql. Both stars were observed at the Observatorio de Sierra Nevada (Granada) in July 2003 with an automatic four-channel Str\"omgren photometer. We also…

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…

Using simultaneous observations in X-rays and optical, we have performed a homogeneous analysis of the cross-correlation behaviours of four X-ray binaries: SWIFT J1753.5-0127, GX 339-4, Sco X-1, and Cyg X-2. With high time-resolution…

We analyze multicolor light curves and high resolution optical spectroscopy of the eclipsing binary and Double Periodic Variable OGLE 05155332-6925581. According to Mennickent et al., this system shows a significant change in the long…

We review X-ray flux modulation from X-ray binaries on time scales corresponding to the orbital period and those at longer time scales (so called superorbital). Those modulations provide a powerful tool to constrain geometry of the…

Context. The post-main-sequence evolution of massive stars remains poorly understood, particularly for blue supergiants. These objects play a crucial role in the dynamical and chemical evolution of galaxies and exhibit pronounced…

Pulsating subdwarf B stars oscillate in short-period $p$-modes or long-period $g$-modes. HS 0702 + 6043 is one of currently three objects known to show characteristics of both types and hence is classified as hybrid pulsator. We briefly…

Aims: Study the high-mass X-ray binary X-7 in M33 using broad-band optical data. Methods: We used recently published CFHT r' and i' data for variable stars in M33 to extract the light curve of the optical counterpart of X-7. We combined…

We present the results of an expanded, long-term radial velocity search (25 yrs) for evidence of binarity in a sample of seven bright proto-planetary nebulae (PPNe). The goal is to investigate the widely-held view that the bipolar or…