相关论文: Kinematic Insights Into Luminous Blue Variables an…

We analyze the late time evolution of 12 supernovae (SNe) occurring over the last ${\sim}$41 years, including nine Type IIP/L, two IIb, and one Ib/c, using UBVR optical data from the Large Binocular Telescope (LBT) and difference imaging.…

Subluminous B stars (sdBs) form the extremely hot end of the horizontal branch and are therefore related to the blue horizontal branch (BHB) stars. While the rotational properties of BHB stars have been investigated extensively, studies of…

We have monitored over a ten-year interval the light variations of five evolved stars with very large mid-infrared excesses. All five objects appear to have oxygen-rich or mixed oxygen-rich and carbon-rich chemistries. They all vary in…

A longstanding problem in the study of supernovae (SNe) has been the relationship between the Type IIP and Type IIL subclasses. Whether they come from distinct progenitors or they are from similar stars with some property that smoothly…

Among the most spectacular variable stars are the Luminous Blue Variables (LBVs), which can show three types of variability. The LBV phase of evolution is poorly understood, and the driving mechanisms for the variability are not known. The…

We present new spectroscopic observations of the He I $\lambda$10830 line in R Coronae Borealis (RCB) stars which provide the first strong evidence that most, if not all, RCB stars have winds. It has long been suggested that when dust forms…

A possible subclass of gamma-ray bursts -- those with few, wide pulses, spectral lags of order one to several seconds, and soft spectra -- has been identified. Their Log[N]-Log[Fp] distribution approximates a -3/2 power-law, suggesting…

While bright, blue, compact galaxies are common at $\rm z \sim 1$, they are relatively rare in the local universe, and their evolutionary paths are uncertain. We have obtained resolved H I observations of nine $\rm z \sim 0$ luminous…

Binary neutron star mergers are believed to eject significant masses with a diverse range of velocities. Once these ejected materials begin to be decelerated by a homogeneous medium, relativistic electrons are mainly cooled down by…

The blue supergiant (BSG) domain contains a large variety of stars whose past and future evolutionary paths are still highly uncertain. Since binary interaction plays a crucial role in the fate of massive stars, investigating the…

We study the spectroscopic evolution of superluminous supernovae (SLSNe) later than 100 days after maximum light. We present new data for Gaia16apd and SN2017egm, and analyse these with a larger sample comprising 41 spectra of 12 events.…

(Abridged) Stars more massive than $20-30M_{\odot}$ are so luminous that the radiation force on the cooler, more opaque outer layers can balance or exceed the force of gravity. These near or super-Eddington outer envelopes represent a long…

Motivated by the historical identification of runaway main-sequence (MS) stars of early spectral type at high Galactic latitudes, we test the capability of Gaia at identifying new such stars. We have selected ~2300 sources with Gaia…

We measure the local rates of ``low-luminosity'' (LL-GRBs, i.e. L<10^{48--49}erg/sec) and ``high-luminosity'' Gamma-ray Bursts (HL-GRBs). The values are in the range n0=100--1800 Gpc^(-3)yr^(-1) and n0=100--550 Gpc^(-3) yr^(-1),…

Supergiant High Mass X-ray Binary systems (sgHMXBs) consist of a massive, late type, star and a neutron star. The massive stars exhibits strong, radiatively driven, stellar winds. Wind accretion onto compact object triggers X-ray emission,…

With the exception of a few well-known and studied systems, the binary population of red supergiants (RSGs) remains relatively uncharacterized. Famous systems such as VV Cep, 31 Cyg and zeta Aur contain RSG + B star binaries and here we…

High resolution spectroscopy with FUSE and STIS of atomic and molecular velocity stratification in the nebular outflow of M27 challenge models for the abundance kinematics in planetary nebulae. The simple picture of a very high speed (~…

VLBI observations of supernovae and gamma-ray bursts provide almost the only way of obtaining spatially resolved information about the sources. In particular, a determination of the expansion velocity of the forward shock, as well as the…

We use numerical simulations to analyze the evolution and properties of superbubbles (SBs), driven by multiple supernovae (SNe), that propagate into the two-phase (warm/cold), cloudy interstellar medium (ISM). We consider a range of mean…

The evolutionary relationships and mechanisms governing the behavior of the wide variety of luminous stars populating the upper H-R diagram are not well established. Luminous blue variables (LBVs) are particularly rare, with only a few…