相关论文: Line-profile variability from tidal flows in Alpha…

Spiral wave patterns observed in models of cardiac arrhythmias and chemical oscillations develop alternans and stationary line defects, which can both be thought of as period-doubling instabilities. These instabilities are observed on…

The vertical shear instability (VSI) is a promising mechanism to drive turbulence in protoplanetary disks. Numerical simulations in the literature demonstrate that the VSI non-linear saturation is predominated by the linear corrugation…

We study in this work the 2D dynamics of an experimental system of disk-shaped rotors, fluidized by turbulent upflow. Contrary to previous knowledge, our experiments show the same particle chiral geometry can produce flows with different…

We have observed variations in the optical emission lines from the X-ray binary Circinus X-1. These variations may be attributed both to orbital variations and to long term secular changes in line strength. We have detected double-peaked…

The eccentric short-period O-star binary BD+60 497 is an interesting laboratory in which to study tidal interactions in massive binary systems, notably via the detection and characterisation of apsidal motion. The rate of apsidal motion in…

We obtained R- and I-band CCD photometry of the soft X-ray transient/neutron- star binary Aql X-1 in 1998 June while it was at quiescence. We find that its light curve is dominated by ellipsoidal variations, although the ellipsoidal…

The VIIRS Day Night Band sensor on the Suomi NPP satellite provides almost a decade of observations of night light. The daily frequency of sampling, without the temporal averaging of annual composites, requires the distinction between…

We have carried out the first survey of the pulsational line profile variability in rapidly oscillating Ap (roAp) stars. We analysed high signal-to-noise time-series observations of ten sharp-lined roAp stars obtained with the…

The polarized and total flux of the BL Lac object PKS 2155-304 were monitored intensively and simultaneously in the optical UBVRI bands with the Turin photopolarimeter at the CASLEO 2.15 m telescope during 4 campaigns in June, August,…

Sagittarius A* exhibits daily energetic flares characterized by non-thermal emission in the infrared and X-ray bands. While the underlying accretion flow is a Radiatively Inefficient Accretion Flow (RIAF) peaking at radio frequencies, the…

Volatile species in protoplanetary discs can undergo a phase change from vapour to solid. These "snow-lines" can play vital roles in planet formation at all scales, from dust coagulation to planetary migration. In the outer regions of…

Measuring surface differential rotation (DR) on different types of stars is important when characterizing the underlying stellar dynamo. It has been suggested that anti-solar DR laws can occur when strong meridional flows exist. We aim to…

We study the two dimensional (2D) line-of-sight velocity ($V_{\rm los}$) field of the low-inclination, late-type galaxy VV304a. The resulting 2D kinematic map reveals a global, coherent and extended perturbation that is likely associated…

We present optical spectropolarimetry of the tidal disruption event (TDE) AT 2019qiz on days $+0$ and $+29$ relative to maximum brightness. Continuum polarization, which informs the shape of the electron-scattering surface, was found to be…

We report observations and analysis of flux monitoring of Sagittarius A* at 3-mm wavelength using the OVRO millimeter interferometer over a period of eight days (2002 May 23-30). Frequent phase and flux referencing (every 5 minutes) with…

The non-axisymmetric features observed in the discs of dwarf novae in outburst are usually considered to be spiral shocks, which are the non-linear relatives of tidally excited waves. This interpretation suffers from a number of problems.…

We calculate the dynamical tides raised on a non-rotating solar-type star by a close stellar or planetary companion. Dissipation arising from a turbulent viscosity operating in the convection zone and radiative damping in the radiative core…

We monitored the BL Lac object S5 0716+714 in the optical band during October 2008, December 2008 and February 2009 with a best temporal resolution of about 5 minutes in the BVRI bands. Four fast flares were observed with amplitudes ranging…

Repeated observations with high spectral resolution acquired in 1998-2008 are used to study the temporal behavior of the spectral line profiles and velocity field in the atmosphere and circumstellar envelope of the post-AGB star V448Lac.…

A radial velocity (RV) survey to detect central stars in binary systems was carried out between 2002 and 2004. De Marco et al. (2004) reported that 10 out of 11 monitored stars exhibited strong RV variability, but periods were not detected.…