相关论文: The dwarf nova SS Cygni: what is wrong?

Quasar microlensing effects make it possible to measure the accretion disc sizes around distant supermassive black holes that are still well beyond the spatial resolution of contemporary instrumentation. The sizes measured with this…

In this study, a new Galactic novae catalogue is introduced collecting important parameters of these sources such as their light curve parameters, classifications, full width half maximum (FWHM) of H$_\alpha$ line, distances and…

We have used HST/COS to obtain a series of 4 FUV (915-2148A) spectroscopic observations of the prototypical dwarf nova U Geminorum during its cooling following a two-week outburst. Our FUV spectral analysis of the data indicates that the…

Gas velocity dispersion measures the amount of disordered motions of a rotating disk. Accurate estimates of this parameter are of the utmost importance because it is directly linked to disk stability and star formation. A global measure of…

Powered by supermassive black holes at their centers, quasars are among the most luminous objects in the Universe, serving as important probes of cosmic history and galaxy evolution. The size of the accretion disc surrounding the black hole…

We consider donor evolution and mass transfer in the microquasar V404 Cyg/GS 2023+338. Based on X-ray observations of its two outbursts, its average mass accretion rate is substantially lower than our model mass-loss rate from its low-mass…

The spiral galaxy NGC 6503 exhibits a regular kinematical structure except for a remarkable drop of the stellar velocity dispersion values in the central region. To investigate the dynamics of the disc a theoretical framework has been…

Trigonometric parallax observations made with the Hubble Space Telescope's Fine Guidance Sensor #3 (HST FGS) of seven Hyades Cluster members in six fields of view have been analyzed along with their proper motions to determine the distance…

We report time-resolved spectroscopic observations of the SU Ursae Majoris dwarf nova, YZ Cnc, for 2 nights over 11 hrs during its 2002 January superoutburst. The spectra only show absorption-line profiles in the first day. But the lines…

We present the last HST/STIS E140M FUV spectrum (1150-1725A) of the dwarf nova (DN) WZ Sge, obtained in July 2004, 3 years following the early superoutburst of July 2001. Single white dwarf (WD) synthetic spectral fits (log{g}=8.5) to the…

Multicolor (BVRI) light curves of the eclipsing novalike variable TT Tri are presented and analyzed with a parameter-fitting eclipse model. The mass ratio of TT Tri is poorly constrained, but must lie roughly in the range…

Novalike cataclysmic variables have persistently high mass transfer rates and prominent steady state accretion disks. We present an analysis of infrared observations of twelve novalikes obtained from the Two Micron All Sky Survey, the…

Determination of the composition and size distribution of dust grains in debris discs is strongly dependent on constraining the underlying spatial distribution of that dust through multi-wavelength, spatially resolved imaging spanning…

Characterization of the properties of young brown dwarfs are important to constraining the formation of objects at the extreme low-mass end of the IMF. While young brown dwarfs share many properties with solar-mass T Tauri stars,…

An accurate model of the point spread function is required in order to estimate positions and brightnesses of stars in digitized images. The PSF of the Gaia space telescope is unusual due to the use of drift-scan mode and time-delayed…

New eclipse timings of the Z Cam-type dwarf nova AY Psc were measured and the orbital ephemeris was revised. Based on the long-term AAVSO data, moreover, the outburst behaviors were also explored. Our analysis suggests that the normal…

Quasi-coherent oscillations have been detected in the extreme ultraviolet flux of the dwarf nova SS Cygni during observations with the Extreme Ultraviolet Explorer satellite of the rise and plateau phases of an anomalous outburst in 1993…

We develop and disseminate effective point-spread functions and geometric-distortion solutions for high-precision astrometry and photometry with the JWST NIRISS instrument. We correct field dependencies and detector effects, and assess the…

We re-analyze data from the gravitational-wave event GW170817 and its host galaxy NGC4993 to demonstrate the importance of accurate total and peculiar velocities when measuring the Hubble constant using this nearby Standard Siren. We show…

A succession of near-IR spectroscopic observations, taken nightly throughout an entire cycle of SS433's orbit, reveal (i) the persistent signature of SS433's accretion disc, having a rotation speed of ~500 km/s, (ii) the presence of the…