Related papers: 'Slow' and Fast Rotators among Hypervelocity Stars

We performed numerical simulations of dynamical encounters between hard massive binaries and a very massive star (VMS; formed through runaway mergers of ordinary stars in the dense core of a young massive star cluster), in order to explore…

The spectroscopic orbit of a circumpolar high-proper-motion visual binary BD +82 565 A component is determined from 57 CORAVEL radial velocity measurements. A short period P = 12.69 d and a moderate eccentricity e = 0.30 are obtained. The…

We have measured the projected rotational velocities (v sin i) of the mass donors for 29 S-type symbiotic stars using high resolution spectroscopic observations and the cross-correlation function (CCF) method. The results of the CCF have…

The discovery of hypervelocity binary stars (HVBs) in the Galactic halo would provide definite evidence of the existence of a massive black hole companion to Sgr A*. Here we use an hybrid approach to compute the rate of ejection and the…

We study three processes that eject hypervelocity (>10^3 km/s) stars from the Galactic center: (i) close encounters of two single stars; (ii) tidal breakup of binary stars by the central black hole, as originally proposed by Hills; and…

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 have measured the projected rotational velocities (vsini) in a number of symbiotic stars and M giants using high resolution spectroscopic observations. On the basis of our measurements and data from the literature, we compare the…

[Abridged] We present the apparent stellar angular momentum of 300 galaxies across the Hubble sequence, using integral-field spectroscopic data from the CALIFA survey. Adopting the same $\lambda_\mathrm{R}$ parameter previously used to…

We report on the results of high dispersion spectroscopy of two `superflare stars', KIC 9766237, and KIC 9944137 with Subaru/HDS. Superflare stars are G-type main sequence stars, but show gigantic flares compared to the Sun, which have been…

We present deep HI 21-cm and optical observations of the face-on spiral galaxy M 83 obtained as part of a project to search for high-velocity clouds (HVCs) in nearby galaxies. Anomalous-velocity neutral gas is detected toward M 83, with…

The empirical distribution of projected rotational velocities (vsini) in massive O-type stars is characterized by a dominant slow velocity component and a tail of fast rotators. Binary interaction has been proposed to play a dominant role…

Recent studies on hypervelocity stars (HVSs) have generated a need to understand the high velocity limits of binary systems. If runaway binary systems with high movement speeds well in excess of 200km/s were to exist, it would have…

The disruption of a binary star system by the massive black hole at the Galactic Centre, SgrA*, can lead to the capture of one star around SgrA* and the ejection of its companion as a hypervelocity star (HVS). We consider the possibility…

High resolution optical spectra of 57 Galactic B-type supergiant stars have been analyzed to determine their rotational and macroturbulent velocities. In addition, their atmospheric parameters (effective temperature, surface gravity and…

Runaway stars are characterized by higher space velocities than typical field stars. They are presumed to have been ejected from their birth places by one or more energetic mechanisms, including supernova explosions. Accurate radial…

Spectroscopic radial velocities for several nearby open clusters suggest that spectra of (especially earlier-type) rapidly rotating stars are systematically blueshifted by 3 km/s or more, relative to the spectra of slowly rotating ones.…

We present radial velocities of the M8V-type, very low-mass star vB 10 that have been obtained at four different epochs of observations between 2001 and 2008. We use high-resolution (R ~ 20,000) near-infrared (J-band) spectra taken with the…

With the help of Gaia DR2, we are able to obtain the full 6-D phase space information for stars from LAMOST DR5. With high precision of position, velocity, and metallicity, the rotation of the local stellar halo is presented using the K…

We observed stars with variable radial velocities to determine their spectroscopic orbits. Velocities of 132 targets taken over a time span reaching 30 years are presented. They were measured with the correlation radial velocity…

We present spectroscopic observations acquired with FLAMES and XSHOOTER at the Very Large Telescope for a sample of 15 Blue Straggler Stars (BSSs) in the globular cluster (GC) M30. The targets have been selected to sample the two BSS…