相关论文: Birth of a Be star: an APOGEE search for Be stars …

Classical Be (CBe) stars are rapidly rotating B-type stars with Balmer emission lines that originated from the decretion disks surrounding them in their spectra. Accounting for $\sim$20% of all B-type stars, most CBe stars are thought to…

Be stars are rapidly rotating main-sequence (MS) stars that play a crucial role in understanding stellar evolution and binary interactions. In this letter, we propose a new formation scenario for black hole (BH) + Be star binaries…

Be stars are a class of rapidly rotating B stars with circumstellar disks that cause Balmer and other line emission. There are three possible reasons for the rapid rotation of Be stars: they may have been born as rapid rotators, spun up by…

Stripped-envelope supernovae (SNe) are H-poor transients produced at the end of the life of massive stars that previously lost their H-rich envelope. Their progenitors are thought to be donor stars in mass-transferring binary systems, which…

LB-1 was originally suggested to harbour a very massive ($ \sim 70 M_\odot $) black hole, but was recently suggested to be a post-mass transfer binary containing a Be star and a helium (He) star. In this paper, we use the binary population…

Stellar-mass black holes have all been discovered through X-ray emission, which arises from the accretion of gas from their binary companions (this gas is either stripped from low-mass stars or supplied as winds from massive ones). Binary…

There is growing evidence that some Be stars were spun up through mass transfer in a close binary system, leaving the former mass donor star as a hot, stripped-down object. There are five known cases of Be stars with hot subdwarf (sdO)…

APOGEE has amassed the largest ever collection of multi-epoch, high-resolution (R~22,500), H-band spectra for B-type emission line (Be) stars. The 128/238 APOGEE Be stars for which emission had never previously been reported serve to…

Because many classical Be stars may owe their nature to mass and angular-momentum transfer in a close binary, the present masses, temperatures, and radii of their components are of high interest for comparison to stellar evolution models.…

Prompted by peculiar spectroscopic variability observed in SDSS/APOGEE $H$-band spectra, we monitored the Be star HD 55606 using optical spectroscopy and found that it is an exotic double-lined spectroscopic binary (SB2) consisting of a Be…

The evolution of helium stars with masses of 1.5 - 6.7 M_sun in binary systems with a 1.4 M_sun neutron-star companion is presented. Such systems are assumed to be the remnants of Be/X-ray binaries with B-star masses in the range of 8 - 20…

Depending principally on mass, the compact object remnant left behind after a star's life may be a white dwarf (WD), neutron star (NS), or black hole (BH). While we have large samples of each of these remnants, we lack knowledge of the…

The emission-line Be star HD 215227 lies within the positional error circle of the newly identified gamma-ray source AGL J2241+4454. We present new blue spectra of the star, and we point out the morphological and variability similarities to…

Be stars are rapid rotators generally produced by binary interactions. The single Be stars in the observations pose challenges to the Be star formation theory. In this paper, we propose a new pathway for the formation of single Be stars, in…

We report the serendipitous discovery of a nitrogen-rich, mildly metal-poor ([Fe/H]=-1.08) giant star in a single-lined spectroscopic binary system found in the SDSS-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE-2)…

Context. The majority of massive stars are born with a close binary companion. How this affects their evolution and fate is still largely uncertain, especially at low metallicity. Aims. We derive synthetic populations of massive…

The theory of binary evolution predicts that many massive stars should lose their hydrogen-rich envelopes via interaction with a companion -- revealing hot helium stars with masses of $\sim$2--8M$_{\odot}$. However, only one candidate…

Classical Be stars, the "e" standing for the presence of spectroscopic line emission, are main sequence stars of spectral type B that are able to form a gaseous disk in Keplerian motion from star-ejected matter. The main driver of this…

Subdwarf B (sdB) stars (and related sdO/sdOB stars) are believed to be helium core-burning objects with very thin hydrogen-rich envelopes. In recent years it has become increasingly clear from observational surveys that a large fraction of…

The spinning-up of the accreting component in the process of conservative mass exchange is considered in binary systems - progenitors of systems consisting of a main sequence Be-star and an O-subdwarf. During the mass exchange, the…