Related papers: The most rapidly rotating He-strong emission line …
We present new long-baseline spectro-interferometric observations of the HerbigAe star HD163296 obtained in the H and K bands with the AMBER instrument at VLTI. The observations cover a range of spatial resolutions between 3 and 12…
Recent papers published in the last years contributed to resolve the enigma on the hypothetical Be nature of the hot pulsating star $\beta$ Cep. This star shows variable emission in the H$\alpha$ line, typical for Be stars, but its…
Through photometric monitoring of the extended transit window of HD 97658b with the MOST space telescope, we have found that this exoplanet transits with an ephemeris consistent with that predicted from radial velocity measurements. The…
We report high-precision transit photometry for the recently detected planet HD 17156b. Using these new data with previously published transit photometry and radial velocity measurements, we perform a combined analysis based on a Markov…
The hot subdwarf HD 49798 has an X-ray emitting compact companion with a spin-period of 13.2 s and a dynamically measured mass of 1.28+/-0.05 M_sun, consistent with either a neutron star or a white dwarf. Using all the available XMM-Newton…
High-resolution optical spectra of eighteen blue horizontal-branch (BHB) stars in the globular cluster M15 indicate that their stellar rotation rates and photospheric compositions vary strongly as a function of effective temperature. Among…
We present a semi-analytical approach for modeling circumstellar emission from rotating hot stars with a strong dipole magnetic field tilted at an arbitrary angle to the rotation axis. By assuming the rigid-field limit in which material…
Stellar rotation is a key in our understanding of both mass-loss and evolution of intermediate and massive stars. It can lead to anisotropic mass-loss in the form of radiative wind or an excretion disk. We wished to spatially resolve the…
The gamma-ray binary 1FGL J1018.6-5856 consists of an O6V((f)) type star and an unknown compact object, and shows orbitally modulated emission from radio to very high energy gamma rays. The X-ray light curve shows a maximum around the same…
In this paper we report the results of high-resolution circular spectropolarimetric monitoring of the Herbig Ae star V380 Ori, in which we discovered a magnetic field in 2005. A careful study of the intensity spectrum reveals the presence…
We present high spatial resolution ($52$ au) observations of the high-mass young stellar object (HMYSO) G345.4938+01.4677 made using the Atacama Large Millimeter/sub-millimeter Array (ALMA). This O-type HMYSO is located at 2.38 kpc and it…
As part of an ongoing search for hypervelocity stars (HVS) I found seventeen two micron all sky survey (2MASS) sources with Gaia G magnitudes less than 16.0 and radial velocities less than -600 km/sec. All these stars are brighter in the K…
The recently discovered soft gamma-ray emission from the anomalous X-ray pulsar 1E 1841-045 has a luminosity L_g ~ 10^{36} ergs/s. This luminosity exceeds the spindown power by three orders of magnitude and must be fed by an alternative…
This paper presents the detection of a periodic dimming event in the lightcurve of the G1.5IV-V type star KIC 1718360. This is based on visible-light observations conducted by both the TESS and Kepler space telescopes. Analysis of the data…
Our long-term photometric monitoring of southern nova-like cataclysmic variables with the 1.3-m SMARTS telescope found BB Doradus fading from V ~ 14.3 towards a deep low state at V ~ 19.3 in April 2008. Here we present time-resolved optical…
We present the first observations of hydrogen line emission detected around the B-type star HD 46487, a well-studied star in the CoRoT field of view. The emission is only evident in the H$\alpha$ line, for which the observed violet-red peak…
We have used the Hubble Space Telescope to acquire new broad-band and narrow-band images of the optical line emission and red continuum associated with the HH 7-11 stellar jet in the NGC 1333 star formation region. Combining the new…
Only 3-4 per cent of galactic O stars are observed to display the emission features representative of the OBe phenomenon, compared to galactic B stars, which display these characteristics in 25-35 per cent of B0 and B1 stars. We present new…
The ON stars are a rare subtype of O stars, of uncertain origin. We report two new, rapidly-rotating ON stars found in data acquired with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope, LAMOST. LS I +61 28 is an ON8.5 Vn…
We present the analysis of the spectroscopic observations of a newly discovered cataclysmic variable HS0551+7241. In 1995 the star's brightness dropped by Delta(B)~2.5 mag and HS0551+7241 entered a low state lasting for ~2 yr. The H-alpha,…