Multiplicity of chemically peculiar stars
نویسندگان
چکیده
Recently, with the goal to study multiplicity of chemically peculiar stars, we carried out a survey of 40 stars using diffraction limited near infrared (IR) imaging with NAOS-CONICA (NACO) at the VLT. Here, we announce the detection of 27 near IR companion candidates around 25 late B-type chemically peculiar stars exhibiting strong overabundances of the chemical elements Hg and Mn in their atmospheres. A key point for the understanding of the abundance patterns in these stars may be connected with binarity and multiplicity. It is intriguing that more than half of the sample of HgMn stars studied previously by speckle interferometry and recently using the adaptive optics system NACO belong to multiple systems.
منابع مشابه
Multiplicity among chemically peculiar stars II . Cool magnetic Ap stars ⋆
We present new orbits for sixteen Ap spectroscopic binaries, four of which might in fact be Am stars, and give their orbital elements. Rough estimates of the individual masses of the components of HD 65339 (53 Cam) are given, combining our radial velocities with the results of speckle interferometry and with Hipparcos parallaxes. Considering the mass functions of 74 spectroscopic binaries from ...
متن کاملMagnesium abundance in main sequence B-type and magnetic chemically peculiar stars
The abundance of magnesium for a sample of 19 main sequence B-type and 41 magnetic chemically peculiar stars has been derived by spectrum synthesis analysis of the Mgii 448.1 nm line under the LTE assumption. The logarithm of the average Mg abundance for the main sequence stars is log (N(Mgii)/N(Tot)) =−4.28±0.19. Comparing magnetic chemically peculiar (Cp) and main sequence stars with equal ef...
متن کاملOn the co - existence of chemically peculiar Bp stars , slowly pulsating B stars and constant B stars in the same part of the H - R diagram
Aims. In order to better model massive B-type stars, we need to understand the physical processes taking place in slowly pulsating B (SPB) stars, chemically peculiar Bp stars, and non-pulsating normal B stars co-existing in the same part of the H-R diagram. Methods. We carry out a comparative study between samples of confirmed and well-studied SPB stars and a sample of well-studied Bp stars wit...
متن کاملChemically peculiar stars in the field of NGC 2244 ?
Low-resolution long-slit spectra of reference stars, including MKK standard stars and well-known chemically peculiar stars, are used to develop a spectroscopic method for the detection of the 5200 Å flux depression in CP stars. This new method is shown to be as sensitive a detection tool as the photometrical techniques, and provides a higher resolution view of the excess blocking. Application t...
متن کاملCatalogue of averaged stellar effective magnetic fields . I . Chemically peculiar A and B type stars
This paper presents the catalogue and the method of determination of averaged quadratic effective magnetic fields B e for 596 main sequence and giant stars. The catalogue is based on measurements of the stellar effective (or mean longitudinal) magnetic field strengths B e , which were compiled from the existing literature. We analysed the properties of 352 chemically peculiar A and B stars in t...
متن کامل