Related papers: HD 69686: A Mysterious High Velocity B Star
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…
We search for periodic variations in the radial velocity of the young Herbig star HD 135344B with the aim to determine a rotation period. We analyzed 44 high-resolution optical spectra taken over a time range of 151 days. The spectra were…
A number of blue stars which appear to be similar to Population I B-stars in the star forming regions of the galactic disk are found more than 1 kpc from the galactic plane. Uncertainties about the true distances and masses of these high…
We first present the multicolor photometry results of the rapidly rotating magnetic star HD 345439 using the Nanshan One-meter Wide-field Telescope. From the photometric observations, we derive a rotational period of 0.7699\pm0.0014 day.…
Runaway stars depart their birthplaces with high peculiar velocities. Two mechanisms are commonly invoked to explain their origin, the binary supernova scenario (BSS) and the dynamical ejection scenario (DES). Investigating the kinematic…
We aim to reveal the nature of the reddest known substellar companion HD 206893 B by studying its near-infrared colors and spectral morphology and by investigating its orbital motion. We fit atmospheric models for giant planets and brown…
We investigate the stellar environment of the Beta Pictoris-like star HD 141569 with optical spectroscopy and near infrared imaging. The B9.5Ve primary, and an M2 and an M4 type star both located in projection less than nine arseconds away…
High-resolution spectroscopy and speckle interferometry reveal the young star HD 86588 as a quadruple system with a 3-tier hierarchy. The 0.3" resolved binary A,B with an estimated period around 300 years contains the 8-year pair Aa,Abc…
The atmosphere of the extremely high-velocity (530-920 km/s) early B-type star HD271791 is enriched in $\alpha$-process elements, which suggests that this star is a former secondary component of a massive tight binary system and that its…
Base on about 4,500 large tangential velocity ($V_\mathrm{tan}>0.75V_\mathrm{esc}$) with high-precision proper motions and $5\sigma$ parallaxes in Gaia DR2 5D information derived from parallax and proper motion, we identify more than 600…
We report the discovery of a unique $z=6.027$ galaxy, multiply imaged by the cluster Abell 383 and detected in new Hubble Space Telescope ACS and WFC3 imaging, as well as in Warm Spitzer observations. This galaxy was selected as a pair of…
We explore the origins of the young B-type stars found by Casetti-Dinescu et al.(2014) at the outskirts of the Milky-Way disk in the sky region of Leading Arm of the Magellanic Stream. High-resolution spectroscopic observations made with…
Most (or possibly all) massive stars reside in multiple systems. From stellar evolution models, numerous systems with an OB star coupled to a black hole would be expected to exist. There have been several claimed detections of such pairs in…
The unusual variable star V838 Monocerotis underwent an eruption in 2002. It continues to illuminate a spectacular series of light echoes, as the outburst light is scattered from circumstellar dust. V838 Mon has an unresolved B3 V companion…
The nearby face-on star forming spiral galaxy NGC 6946 is known as the Fireworks Galaxy due to its hosting an unusually large number of supernova. We analyze its resolved near-ultraviolet (NUV) stellar photometry measured from images taken…
Regular star formation is thought to be inhibited close to the massive black hole (MBH) in the Galactic center. Nevertheless, tens of young main sequence B stars have been observed in an isotropic distribution close to it. Various models…
The distance to the fireworks galaxy NGC 6946 is highly uncertain. Recent distance estimates using the tip of the red giant branch of 7.7 to 7.8 Mpc are larger than the distance commonly assumed for studying supernovae in this galaxy of 5.9…
We report the discovery of a square axisymmetric circumstellar nebula around the emission-line star HD 93795 in archival Spitzer Space Telescope 24 micron data. We classify HD 93795 as an B9 Ia star using optical spectra obtained with the…
Using new HST imaging, we identify a large, evolved system of super star clusters in a disk region just outside the starburst core in the prototypical starburst galaxy M82, ``M82 B.'' This region has been suspected to be a fossil starburst…
We present deep Hubble Space Telescope/Wide Field and Planetary Camera 2 photometry of the young HD 97950 star cluster in the giant H {\sc ii} region NGC 3603. The data were obtained in 1997 and 2007 permitting us to derive membership based…