Related papers: Hypervelocity Stars II. The Bound Population
We predict the distinctive three dimensional space motions of hypervelocity stars (HVSs) and runaway stars moving in a realistic Galactic potential. For nearby stars with distances less than 10~kpc, unbound stars are rare; proper motions…
The dense cores of Milky Way globular clusters (GCs) play host to a variety of dynamical encounters between stellar objects, which can accelerate stars to velocities high enough to escape the GC. The most extreme examples of these…
A supermassive black hole ejected from the center of a galaxy by gravitational wave recoil carries a retinue of bound stars - a "hypercompact stellar system" (HCSS). The numbers and properties of HCSSs contain information about the merger…
We report the detection of five high-velocity stars in the core of the globular cluster NGC 2808. The stars lie on the the red giant branch and show total velocities between 40 and 45 km/s. For a core velocity dispersion sigma_c = 13.4…
We measure the projected rotational velocities of the late B-type hypervelocity stars HVS7 and HVS8 from high resolution spectroscopy to be 60 +/- 17 km/s and 260 +/- 70 km/s. The 'slow' rotation of HVS7 is in principle consistent with…
We explore the hypothesis that some high-velocity runaway stars attain their peculiar velocities in the course of exchange encounters between hard massive binaries and a very massive star (either an ordinary 50-100 Msun star or a more…
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…
High-velocity clouds (HVCs) are clouds of HI seen around the Milky Way with velocities inconsistent with Galactic rotation, have unknown distances and masses and controversial origins. One possibility is that HVCs are associated with the…
Based on the second Gaia data (Gaia DR2) and spectroscopy from the LAMOST Data Release 5, we defined the high-velocity (HiVel) stars sample as those stars with $v_{\mathrm{gc}} > 0.85 v_{\mathrm{esc}}$, and derived the final sample of 24…
Hypervelocity stars (HVSs) ejected from the Galactic Center (GC) at speeds faster than the Galactic escape velocity are useful tools to provide insight into the Milky Way's dark matter halo. However, most characterizations of HVS orbits…
Motivated by detections of hypervelocity stars that may originate from the Galactic Center, we revist the problem of a binary disruption by a passage near a much more massive point mass. The six order of magnitude mass ratio between the…
High Velocity Clouds (HVCs) have recently attracted renewed attention as being long lived, massive dark matter dominated clouds of primordial composition distributed throughout the Local Group. In this picture the HVCs would contain a few…
Hyper-velocity stars (HVS) are enigmatic objects because they are travelling so fast that they escape from the Galaxy. Among hot subdwarfs, only one such star is known, the He-sdO US 708. The Hyper-MUCHFUSS collaboration provided additional…
Context: Hyper-velocity stars move so fast that only a supermassive black hole (SMBH) seems to be capable to accelerate them. Hence the Galactic centre (GC) is their only suggested place of origin. Edelmann et al. (2005) found the early…
We estimate the distribution of ejection velocities for the known population of high galactic latitude runaway stars. The initial sample is a collection of 174 early-type stars selected from the literature. The stars are first classified…
We present an analysis of the chemical abundances and kinematics of six low-mass dwarf stars, previously claimed to be candidate hypervelocity stars (HVSs). We obtained moderate-resolution ($R\sim$ 6000) spectra of these stars to estimate…
High-velocity clouds (HVC), fast-moving ionized and neutral gas clouds found at high galactic latitudes, may play an important role in the evolution of the Milky Way. The extent of this role depends sensitively on their distances and total…
Since the discovery of hypervelocity stars in 2005, it has been widely believed that only the disruption of a binary system by a supermassive black hole at the Galactic center (GC), that is, the so-called Hills mechanism, is capable of…
We report the discovery of DESI-HVS1, a hypervelocity star (HVS) candidate identified from DESI DR1 spectroscopy and Gaia DR3 astrometry. DESI-HVS1 is an old, low-mass, metal-poor F-type star with a mass of $0.8\,M_\odot$, an age of…
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…