相关论文: Candidate Ap stars in close binary systems
We investigate the magnetic dichotomy between Ap/Bp and other A-type stars by carrying out a deep spectropolarimetric study of Am and HgMn stars. Using the NARVAL spectropolarimeter at the Telescope Bernard Lyot (Observatoire du Pic du…
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…
Recently, Tiwari, Chaubey, & Pandey (2007) detected the bright component of the visual binary HD151878 to exhibit rapid photometric oscillations through a Johnson B filter with a period of 6 min (2.78 mHz) and a high, modulated amplitude up…
The origin of chemically peculiar stars remains enigmatic, especially regarding their frequency among their "normal" peers. In addition to magnetic fields and rotation, multiplicity may shed light on the question. We mention the main…
Doppler measurements of two G-type main-sequence stars, HD210277 and HD168443, reveal Keplerian variations that imply the presence of companions with masses (M sin i) of 1.28 and 5.04 M_Jup and orbital periods of 437 d and 58 d,…
Stars with radiative envelopes, specifically the upper main sequence chemically peculiar (Ap) stars, were among the first objects outside our solar system for which surface magnetic fields have been detected. Currently magnetic Ap stars…
Binary stars are ubiquitous; the majority of solar-type stars exist in binaries. Exoplanet occurrence rate is suppressed in binaries, but some multiples do still host planets. Binaries cause observational biases in planet parameters, with…
Moderately close binaries are a special class of targets for planet searches. From a theoretical standpoint, their hospitality to giant planets is uncertain and debated. From an observational standpoint, many of these systems present…
We present photometric, astrometric, and spectroscopic observations of USco160611.9-193532 AB, a candidate ultrawide (~1600 AU), low-mass (M_tot~0.4 M_sun) multiple system in the nearby OB association Upper Scorpius. We conclude that both…
High-resolution circular spectropolarimetric observations, obtained with ESPaDOnS in the context of the BinaMIcS Large Program, have revealed a magnetic field in the B3V secondary component of the SB2 binary system $\epsilon$ Lupi (B2/B3).…
The discovery of exotic abundances, chemical inhomogeneities, and weak magnetic fields on the surface of late B-type primaries in spectroscopic binaries has important implications not only for our understanding of the formation mechanisms…
As part of an astrometric program, we have used the Very Long Baseline Array to measure the trigonometric parallax of several young stars in the Taurus and Ophiuchus star-forming regions with great accuracy. Additionally, we have obtained…
HD 62658 (B9p V) is a little-studied chemically peculiar star. Light curves obtained by the Kilodegree Extremely Little Telescope (KELT) and Transiting Exoplanet Survey Satellite (TESS) show clear eclipses with a period of about 4.75 d, as…
We explore the probable chemical signature of planet formation in the remarkable binary system HD 106515. The A star hosts a massive long-period planet with 9 MJup detected by radial velocity. We also refine stellar and planetary parameters…
I present the results of time-resolved photometry of a selection of central stars of planetary nebulae. The study reveals periodic variability in two of the eight central stars observed, those of NGC 6026 and NGC 6337. The variability…
The absence of magnetic white dwarfs with a non-degenerate low-mass stellar companion in a wide binary is still very intriguing and at odds with the hypothesis that magnetic white dwarfs are the progenies of the magnetically peculiar Ap/Bp…
Subluminous B (sdB) stars can result from stable Roche lobe overflow or common envelope ejection in close binary systems. The companions are either low mass main sequence stars or white dwarfs. We discuss mass determinations for sdB stars…
Close binary stars are binary stars where the component stars are close enough such that they can exchange mass and/or energy. They are subdivided into semi-detached, overcontact or ellipsoidal binary stars. A challenging problem in the…
Planet(s) in binaries are unique architectures for testing predictions of planetary formation and evolution theories in very hostile environments. We used the IRDIS dual-band imager of SPHERE at VLT, and the speckle interferometric camera…
The origin of the magnetic fields of the chemically peculiar main sequence Ap/Bp stars is still matter of intense debate. The recent discoveries of magnetic fields in Herbig Ae/Be stars using high resolution data obtained with the…