相关论文: BRITEning up the Be Phenomenon

In the regime of strong mode coupling, the modal gains and losses and the modal group delays of a multimode fiber are known to have well-defined statistical properties. In mode-division multiplexing, mode-dependent gains and losses are…

Variability and mass-loss are common phenomena in massive OB-type stars. It is argued that they are caused by violent strange mode instabilities identified in corresponding stellar models. We present a systematic linear stability analysis…

How the event rate of fast radio bursts (FRBs) evolves with redshift is a hot topic to explore their cosmological origin and the circum-burst environment. Particularly, it is urgent to know what the difference of event rates between…

We have observed S4 0954+658 in the BVRI bands in 2001, and in the BI bands in 2002. The observations resulted in almost evenly sampled light curves, 3-8 hours long, with an average sampling interval of ~5-15 min. Because of the dense…

Increased share of renewable sources of energy in a power grid leads to larger deviations in grid frequency from the nominal value resulting in more challenging control and its modelling. In this paper we focus on the grid frequency for the…

The oscillatory magnetoresistance spectrum of the organic metal (BEDO)$_5$Ni(CN)$_4\cdot$3C$_2$H$_4$(OH)$_2$ has been studied up to 50 T, in the temperature range from 1.5 K to 4.2 K. In high magnetic field, its Fermi surface corresponds to…

The accreting millisecond pulsar XTE J1814-338 exhibits oscillations at the known spin frequency during Type I X-ray bursts. The properties of the burst oscillations reflect the nature of the thermal asymmetry on the stellar surface. We…

We have derived beryllium abundances in a wide sample of stars hosting planets, with spectral types in the range F7V-K0V, aimed at studying in detail the effects of the presence of planets on the structure and evolution of the associated…

Photo-luminescence intermittency (blinking) in semiconductor nanocrystals (NCs), a phenomenon ubiquitous to single-emitters, is generally considered to be temporally random intensity fluctuations between bright (On) and dark (Off) states.…

The transmissivity of a one-dimensional random system that is periodic on average is studied. It is shown that the transmission coefficient for frequencies corresponding to a gap in the band structure of the average periodic system…

Among the emission-line stars, the classical Be stars known for their extreme properties are remarkable. The Be stars are B-type main sequence stars that have displayed at least once in their life emission lines in their spectrum. Beyond…

This paper checks on the roles of metallicity and evolutionary age in the appearance of the so-called Be phenomenon. Slitless CCD spectra were obtained covering the bulk of the Small Magellanic Cloud. For Halpha line emission twice as…

The comparative primary cosmic rays (PCR) comparative analysis by E0 and the spectra of variable stars by periods is carried out in order to establish the causes of irregularities in the spectrum of PCR by E0. The relationship between the…

We report evidence for a new class of variable star, which we dub millimagnitude RR Lyrae (mmRR). From K2 observations of the globular cluster M4, we find that out of 24 horizontal branch stars not previously known to be RR Lyrae variables,…

Previous studies have observed significant photometric differences between non-emission B-type and classical Be stars, however the precise mechanism responsible for these differences is unclear. This study combines the Bright Star Catalogue…

Galactic field Be stars were studied by taking into account the effects induced by the fast rotation on their fundamental parameters. Fractional ages $\tau/\tau\_{\rm MS}$ ($\tau\_{\rm MS}$ = time spent in the MS) against stellar mass…

Fourier analysis of the light curve of AC And from the HATNet database reveals the rich frequency structure of this object. Above 30 components are found down to the amplitude of 3 mmag. Several of these frequencies are not the linear…

Drift pairs are an unusual type of fine structure sometimes observed in dynamic spectra of solar radio emission. They appear as two identical short narrowband drifting stripes separated in time; both positive and negative frequency drifts…

From TESS photometry, 493 mid- to late-B stars with high frequencies (Maia variables) have been identified. The distribution of projected rotational velocities shows that the rotation rates of Maia variables are no different from those of…

The jet properties of Mrk 501 and 3C 279 are derived by fitting the broadband spectral energy distributions with the lepton models. The derived gamma_b (the break Lorenz factor of the electron distribution) are 10^4-10^6 for Mrk 501 and…