Related papers: PG 1610$+$062: a runaway B star challenging classi…
[Context.] The hot subdwarf B star HS0702+6043 is known as a large-amplitude, short-period p-mode pulsator of the EC14026 type. Its atmospheric parameters place it at the common boundary between the empirical instability regions of the…
A relevant fraction of massive stars are runaways, moving with a significant peculiar velocity with respect to their environment. Kicks from supernova explosions or the dynamical ejection of stars from clusters can account for the runaway…
We present an analysis of high-speed spectroscopy of the pulsating subdwarf B star PG 1605+072. Periodic radial motions are detected at frequencies similar to those reported for photometric variations in the star, with amplitudes of up to 6…
Very few examples are known of red supergiant runaways, all of them descending from the more massive O-type precursors, but none from the lower mass B-type precursors, although runaway statistics among B-type stars suggest that K-type…
This paper continues the analysis of faint high latitude B stars from Martin (2004). Here we analyze the kinematics of the stars and combine them with the abundance information from the first paper to classify each one. The sample contains…
In this paper, we report the discovery of a new late-B type unbound hyper-runaway star (LAMOST-HVS4) from the LAMOST spectroscopic surveys. According to its atmospheric parameters, it is either a B-type main sequence (MS) star or a blue…
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…
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…
The hypervelocity stars recently found in the Galactic halo are expelled from the Galactic center through interactions between binary stars and the central massive black hole or between single stars and a hypothetical massive binary black…
We report the discovery of 30 stars with extreme space velocities ($>$ 480 km/s) in the Gaia-DR2 archive. These stars are a subset of 1743 stars with high-precision parallax, large tangential velocity ($v_{tan}>$ 300 km/s), and measured…
We present the latest results from our analysis of time resolved spectroscopy of PG 1605+072, a high amplitude pulsating sdB star. The star is believed to have evolved off the extreme horizontal branch, and it is uncertain whether it…
Runaway stars ejected from the Galactic disk populate the halo of the Milky Way. To predict the spatial and kinematic properties of runaways, we inject stars into a Galactic potential, compute their trajectories through the Galaxy, and…
The star EPIC 210894022 has been identified from a light curve acquired through the K2 space mission as possibly orbited by a transiting planet. Our aim is to confirm the planetary nature of the object and derive its fundamental parameters.…
PG 1605+072 has unique pulsational properties amongst the members of the new class of pulsating sdB (EC 14026) stars. It has the longest periods and the richest, most puzzling frequency spectrum (55 periods). We present a quantitative…
We present an investigation of the known sample of runaway stars. The orbits of these stars are traced back to their origin in the Galactic disc. The velocity distribution of these stars is compared to theoretical predictions. We conclude…
HP~Tau/G2 is a luminous, short-period, fast-rotating G-type weak-line T Tauri star with a large radius, an oblate shape with gravity-darkening, little circumstellar material, and centered in a slowly expanding cloud cavity. It is an X-ray…
Stars ejected from the Galactic centre can be used to place important constraints on the Milky Way potential. Since existing hypervelocity stars are too distant to accurately determine orbits, we have conducted a search for nearby…
Over the past decade, runaway stars have been identified, believed to originate either as surviving donors of Type Ia supernovae or as partially deflagrated accretors producing Type Iax supernovae. While the former have been extensively…
Gaia DR3 data have revealed new massive runaway stars, while spectroscopic surveys enable detailed characterization. The relative contributions of binary supernova (BSS) and dynamical ejection (DES) scenarios to explain their runaway origin…
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…