Related papers: AG Carinae: a Luminous Blue Variable with a high r…
The colliding wind binary (CWB) systems \eta\ Carinae and WR140 provide unique laboratories for X-ray astrophysics. Their wind-wind collisions produce hard X-rays that have been monitored extensively by several X-ray telescopes, including…
Over the five years of high-resolution spectroscopy of the cool star identified with the IR source IRAS20508+2011, the photospheric radial velocity variability Vr=15-30km/s is detected. In the same time, the Halpha profile varied from an…
We present the results of an intensive photometric and spectroscopic monitoring campaign of the WN4 Wolf-Rayet (WR) star WR1=HD4004. Our broadband V photometry covering a timespan of 91 days shows variability with a period of…
FU Orionis systems are young stars undergoing outbursts of disc accretion and where the optical spectrum contains lines associated with both the disc photosphere and a wind component. Previous observations of the prototype FU Orionis have…
We present the first results from a recently concluded study of GRBs at $z\gtrsim5$ with the Karl G. Jansky Very Large Array (VLA). Spanning $1$ to $85.5$ GHz and 7 epochs from 1.5 to 82.3 d, our observations of GRB 140311A are the most…
We present mid-IR observations of the Galactic Luminous Blue Variable (LBV) HR Car and its associated nebula carried out with the Spitzer Space Telescope using both IRAC and IRS, as part of a GTO program aimed to study stellar ejecta from…
We observed Circinus X-1 twice during a newly reached low-flux phase near zero orbital phase using the High-Energy Transmission Grating Spectrometer (HETGS) onboard Chandra. In both observations the source did not show the P Cygni lines we…
We present two new luminous blue variable (LBV) candidate stars discovered in the M33 galaxy. We identified these stars (Valeev et al. 2010) as massive star candidates at the final stages of evolution, presumably with a notable interstellar…
We quantify the rapid variations in X-ray brightness ("flares") from the extremely massive colliding wind binary Eta Carinae seen during the past three orbital cycles by RXTE. The observed flares tend to be shorter in duration and more…
BZ Cam is the first cataclysmic variable star with an accretion disk wind evident in its optical spectrum. The wind was found by Thorstensen, who discovered intermittent P Cygni profiles occurring simultaneously in He I 5876 Angstroms and H…
In this Letter, we report the results of spectroscopic and photometric monitoring of the candidate luminous blue variable (LBV) WS1, which was discovered in 2011 through the detection of a mid-infrared circular shell and follow-up optical…
We investigate the physical properties of large-scale wind structures around massive hot stars with radiatively-driven winds. We observe Discrete Absorption Components (DACs) in optical He I P Cygni lines of the LBV binary MWC 314…
We characterise the variability in the physical properties of the luminous blue variable AFGL2298 between 1989-2008. In conjunction with published data from 1989-2001, we have undertaken a long term (2001-2008) near-IR spectroscopic and…
We present the results of a study of spectral features and the velocity field in the atmosphere and the circumstellar envelope of the hypergiant V1302 Aql, the optical counterpart of the IR source IRC+10420, based on high-resolution…
Optical spectra obtained in 2006-07 of the nova-like cataclysmic variable QU Car are studied for radial velocities, line profiles, and line identifications. We are not able to confirm the reported 10.9 hr orbital period from 1982,partly…
MWC 314 is one of the most luminous stars in the Milky Way. Its fundamental parameters are similar to those of LBVs, although no large photometric variations have been recorded. We analyzed the radial velocity (RV) variations displayed by…
The colliding-wind binary system $\eta$ Carinae has been identified as a source of high-energy (HE, below $\sim$100\,GeV) and very-high-energy (VHE, above $\sim$100\,GeV) gamma rays in the last decade, making it unique among these systems.…
We report the detection of rapid wavelength and intensity variations of narrow components in absorption line profiles of the hot galactic supergiant P Cygni. During most of the time, in one week of observations, there were two such…
We present high sensitivity Very Long Baseline Interferometry (VLBI) observations 806 days after the gamma-ray burst of 2003 March 29 (GRB030329). The angular diameter of the radio afterglow is measured to be 0.347 +- 0.09 mas,…
We present results from observations of H110alpha recombination-line emission at 4.874 GHz and the related 4.8-GHz continuum emission towards the Carina Nebula using the Australia Telescope Compact Array. These data provide information on…