相关论文: Periodicities in the K2 lightcurve of HP Librae

We use a relativistic ray-tracing code to calculate the light curves observed from a global general relativistic magneto-hydrodynamic simulation of an accretion flow onto a Schwarzschild black hole. We apply three basic emission models to…

We analyse high-time-resolution spectroscopy of the AM CVn stars HP Librae and V803 Centauri, taken with the New Technology Telescope (NTT) and the Very Large Telescope (VLT) of the European Southern Observatory, Chile. We present evidence…

We present the discovery of SDSS J135154.46-064309.0, a short-period variable observed using 30-minute cadence photometry in K2 Campaign 6. Follow-up spectroscopy and high-speed photometry support a classification as a new member of the…

A dense series of long and high time resolution light curves of the old nova V603 Aql, covering 22 nights (19 of which are consecutive), are analyzed in order to identify and characterize variations on the time scale of hours and days. The…

Here we present the results of visible range light curve observations of ten Centaurs using the Kepler Space Telescope in the framework of the K2 mission. Well defined periodic light curves are obtained in six cases allowing us to derive…

We analyze two sectors of TESS photometry of the nova-like cataclysmic variable star V533 Her. We detect a periodicity consistent with the binary orbital period and estimate a revised value of 3.53709(2) hr. We also detect a strong signal…

{\it Kepler} satellite photometry and phase-resolved spectroscopy of the ultracompact AM CVn type binary SDSS J190817.07+394036.4 are presented. The average spectra reveal a variety of weak metal lines of different species, including…

Low and intermediate frequency quasi-periodic oscillations (QPOs) in black hole candidates are believed to be due to oscillations of the Comptonizing regions in an accretion flow. Assuming that the general structure of an accretion disk is…

We present the results of a two and a half year optical photometric monitoring programme covering 16 AM CVn binaries using the Liverpool Telescope on La Palma. We detected outbursts in seven systems, one of which (SDSS J0129) was seen in…

Phase-resolved spectroscopy of four AM CVn systems obtained with the William Herschel Telescope and the Gran Telescopio de Canarias (GTC) is presented. SDSS\,J120841.96+355025.2 was found to have an orbital period of 52.96$\pm$0.40\,min and…

Periodic outbursts are observed in many AGNs and usually explained with a supermassive black hole binary (SMBHB) scenario. However, multiple periods are observed in some AGNs and cannot be explained with it. Here we analyze the periodicity…

Two similar periodicities (3001 and 3028 s) are known from the X-ray and optical light curves of V1405 Aql, a low mass X-ray Binary (LMXRB). Two competing models have been offered for this system. According to the first, V1405 Aql is a…

In an effort to characterize variations on the time scale of hours and smaller during the high and low states of the novalike variable TT Ari, light curves taken over the course of more than 40 yr are analyzed. It is found that the well…

We present an 80-d long uninterrupted high-cadence K2 light curve of the B1Iab supergiant rho Leo (HD 91316), deduced with the method of halo photometry. This light curve reveals a dominant frequency of $f_{\rmrot}=0.0373$d$^{-1}$ and its…

Recently, brightness variations occurring on twice the accretion disk precession period in the old nova and permanent superhump system V603 Aql have been observed by Bruch & Cook (2018). In an attempt to detect a similar effect in other…

Accreting stellar mass black holes (BHs) routinely exhibit Type-C quasi-periodic oscillations (QPOs). These are often interpreted as Lense-Thirring precession of the inner accretion flow, a relativistic effect whereby the spin of the BH…

We have obtained observations of the ultraviolet spectrum of AM CVn, an ultra-short-period helium cataclysmic variable, using the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope (HST). We obtained data in…

We report evidence for a quasi-periodic oscillation (QPO) in the optical light curve of KIC 9650712, a narrow-line Seyfert 1 galaxy in the original Kepler field. After the development and application of a pipeline for Kepler data specific…

We present Keck II spectroscopy of an optical mHz quasi-periodic oscillations (QPOs) in the lightcurve of the X-ray pulsar binary Her X-1. In the power spectrum it appears as `peaked noise', with a coherency $\sim$2, a central frequency of…

Observations of the ultraviolet continuum of the X-ray binary system Her X-1/HZ Herculis with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope show quasiperiodic oscillations (QPOs) at frequencies of 8+/-2 and 43+/-2…