相关论文: Discovery of X-ray flaring on the magnetic Bp-star…

We present new UBVRI observations of the magnetic Bp star sigma Ori E. The basic features of the star's lightcurve have not changed since the previous monitoring by Hesser et al. (1977), indicating that the star's magnetosphere has remained…

We present XMM-Newton observations of the young (~2-5 Myr) cluster around the hot (O9.5V) star sigma Orionis AB, aimed at obtaining a high resolution RGS spectrum of the hot star as well as EPIC imaging data for the whole field. We show…

We present the results of a 140 ks XMM-Newton observation of the B2 star $\rho$ Ophiuchi A. The star has exhibited strong X-ray variability: a cusp-shaped increase of rate, similar to that which we partially observed in 2013, and a bright…

The young O9.5 V spectroscopic binary Theta 2 Ori A shows moderately hard X-ray emission and relatively narrow X-ray lines, suggesting that it may be a Magnetically Confined Wind Shock (MCWS) source, similar to its more massive analogue…

The Kepler and TESS space missions significantly expanded our knowledge of what types of stars display flaring activity by recording a vast amount of super-flares from solar-like stars, as well as detecting flares from hotter stars of A-F…

Weak-line T Tauri stars (WTTS) exhibit X-ray flares, likely resulting from magnetic reconnection that heats the stellar plasma to very high temperatures. These flares are difficult to identify through targeted observations. Here, we report…

Sigma Ori E, a massive helium B-type star, shows a high surface rotation and a strong surface magnetic field potentially challenging the process of wind magnetic braking. The Gaia satellite provides an accurate distance to that star and…

We report the serendipitous discovery of a flare star observed with the ROSAT X-ray observatory. From optical spectra, which show strong and variable emission lines of the hydrogen Balmer series and neutral helium, we classify this object…

A mysterious X-ray-emitting object has been detected moving away from the high-mass gamma-ray binary PSR B1259-63, which contains a non-accreting pulsar and a Be star whose winds collide forming a complex interaction structure. Given the…

We present high resolution AO-corrected coronographic near-infrared imaging on the early-type Herbig Be star MWC 297. X-ray flaring has been reported towards this young object, however this has been difficult to reconcile with its early…

The flare/spotted spectroscopic binary star CC Eri was observed with the Position Sensitive Proportional Counter (PSPC) on the X-ray satellite ROSAT on 1990 July 9-11 and 1992 January 26-27. During the observations, the source was variable…

For flares to be generated, stars have to have a sufficiently deep outer convection zone (F5 and later), strong large--scale magnetic fields (Ap/Bp-type stars) or strong, radiatively driven winds (B5 and earlier). Normal A-type stars…

We present a comprehensive study of X-ray emission and wind properties of massive magnetic early B-type stars. Dedicated XMM-Newton observations were obtained for three stars xi1 CMa, V2052 Oph, and zeta Cas. We report the first detection…

Flares from the Sun and other stars are most prominently observed in the soft X-ray band. Most of the radiated energy, however, is released at optical/UV wavelengths. In spite of decades of investigation, the physics of flares is not fully…

Circumstantial evidence suggests that magnetism and enhanced X-ray emission are likely correlated in early B-type stars: similar fractions of them ($\sim$ 10 %) are strong and hard X-ray sources and possess strong magnetic fields. It is…

We report on a large X-ray flare from the Lindroos binary system HD 560 during a pointed ROSAT PSPC observation. Strong magnetic activity is expected for the late-type component (a G dwarf star and post-T Tauri Star candidate). The system…

Observations of nearby star forming clouds with imaging X-ray telescopes have revealed that X-ray emission is elevated $10^1-10^4$ above main sequence levels in low-mass pre-main sequence (PMS) stars. The variability and spectral X-ray…

A common explanation for the observed X-ray emission of A-type stars is the presence of a hidden late-type companion. While this hypothesis can be shown to be correct in some cases, there is also evidence suggesting that low-mass companions…

Magnetic early B-type stars are rare. To identify them, we use the strongest indirect indicator of a magnetic field in B stars, which is periodic variability of UV stellar wind lines occurring symmetric about the approximate rest…

The famous, very young, helium rich, magnetically-active, radio and X-ray emitter, short-period rotationally variable, spectroscopically peculiar star {\sigma} Ori E may have a close late-type stellar companion, which could explain flaring…