相关论文: Very peculiar wind from BD+53 2790, the optical co…
The number of magnetic stars detected among massive stars is small; nevertheless, the role played by the magnetic field in stellar evolution cannot be disregarded. Links between line profile variability, enhancements/depletions of surface…
The southern magnetic Bp star HD 137509 exhibits complex rotational modulation of the longitudinal field and other magnetic observables. Interpretation of this magnetic variability in the framework of the low-order multipolar field models…
Be objects are stars of B spectral type showing lines of the Balmer series in emission. The presence of these lines is attributed to the existence of an extended envelope, disk type, around them. Some stars are observed in both the Be and…
A study is presented regarding the nature of several variable stars sampled during a campaign of photometric monitoring from the Abbey Ridge Observatory: 3 eclipsing binaries, 2 semiregulars, a luminous Be star, and a star of uncertain…
PSR B1259-63/LS 2883 is a binary system where a 48 ms pulsar orbits a massive Be star with a highly eccentric orbit (e=0.87) with a period of 3.4 years. The system exhibits variable, non-thermal radiation visible from radio to very high…
The 5.9 M_sun star HD 125823 is a striking helium variable with a period of 8.82 d, ranging in helium spectral type from He-strong B2 to He-weak B8. For the first time we present here observational evidence for the appearance of emission…
BD+20 1790 is a young active, metal-rich, late-type K5Ve star. We have undertaken a study of stellar activity and kinematics for this star over the past few years. Previous results show a high level of stellar activity, with the presence of…
The O9.7 V star HD 54879 is currently the only massive magnetic star whose magnetic field geometry and rotation period are not constrained. Over the last three years, we gathered additional observations of this star, obtained using various…
HD 142990 (V 913 Sco; B5 V) is a He-weak star with a strong surface magnetic field and a short rotation period ($P_{\rm rot} \sim 1$ d). While it is clearly a rapid rotator, recent determinations of $P_{\rm rot}$ are in formal disagreement.…
We present the results of a long-term monitoring campaign of the H\alpha line in a sample of bright OB-supergiants (O7.5-B9) that aims at detecting rotationally modulated changes potentially related to the existence of large-scale wind…
PSR B1259-63 is a 48 ms radio pulsar in a highly eccentric 3.4 year orbit with a Be star SS 2883. Unpulsed gamma-ray, X-ray and radio emission components are observed from the binary system. It is likely that the collision of the pulsar…
Using observations from Chandra, Swift and XMM-Newton, we investigate the high-energy properties of all known (18) Be+sdO systems as well as 7 additional Be binaries suspected to harbour stripped stars. The observed X-ray properties are…
We present new radial velocities of the high-mass X-ray binary star 4U 2206+54 based on optical spectra obtained with the Coude spectrograph at the 2m RCC telescope at the Rozhen National Astronomical Observatory, Bulgaria in the period…
We observed PSR B1259-63, a young non-accreting pulsar orbiting around a Be star SS 2883, eight times with the Suzaku satellite in 2007, to characterize the X-ray emission arising from the interaction between a pulsar relativistic wind and…
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.…
Context: Nonthermal radio emission in massive stars is expected to arise in wind-wind collisions occurring inside a binary system. One such case, the O-type star Cyg OB2 #9, was proven to be a binary only four years ago, but the orbital…
The light variability of hot magnetic chemically peculiar stars is typically caused by the flux redistribution in spots with peculiar abundance. This raises the question why some stars with surface abundance spots show significant…
An exceptionally bright new X-ray source in the Large Magellanic Cloud was discovered by the Swift/BAT telescope on MJD 54923 (2 April 2009), and shown to have a pulse period of 27s using follow-up observations by RXTE/PCA. We report here…
We present an analysis of long-term optical monitoring observations and optical spectroscopic observations of the counterpart to CXOU J205847.5+414637 (high mass X-ray binary system). We search for a variability in the light curve of Be…
Spectroscopic and photometric variability is widespread among O-type supergiants. It is linked to various phenomena affecting the star and its circumstellar environment, thereby providing direct information concerning them. To investigate…