Related papers: On the lambda Bootis spectroscopic binary hypothes…
12 Bootis is a double-lined spectroscopic binary whose orbit has been resolved by interferometry. We present a detailed modelling of the system and show that the available observational constraints can be reproduced by models at different…
The hydrogen-line spectrum of eight lambda Boo type stars is studied. The observed H_delta and H_gamma profiles are compared with Kurucz's theoretical profiles. The existence of weak emission-like details in the cores of five lambda Boo…
We analyse TESS light curves for 70 southern $\lambda$ Boo stars to identify binaries and to determine which of them pulsate as $\delta$ Scuti stars. We find two heartbeat stars and two eclipsing binaries among the sample. We calculate that…
The assertion that there is an intrinsic excess of binaries with mass ratios q \simeq 1 - the twin hypothesis - is investigated. A strong version of this hypothesis (H_s), due to Lucy & Ricco (1979) and Tokovinin (2000), refers to a narrow…
Wide binaries are tracers of the gravity field of the Galaxy, but their study requires some caution. A large list of common proper motion stars selected from the AGK3 were monitored with the CORAVEL spectrovelocimeter, in order to prepare a…
We demonstrate that HD 174005, a star recently classified as belonging to the lambda Boo group, is in reality a double lined spectroscopic binary; at some phases, the observed composite spectrum may be similar to that of a single star with…
The alpha Centauri binary system, owing to its duplicity, proximity and brightness, and its components' likeness to the Sun, is a fundamental calibrating object for the theory of stellar structure and evolution and the determination of…
Spectra of late-type stars are usually analyzed with static model atmospheres in local thermodynamic equilibrium (LTE) and a homogeneous plane-parallel or spherically symmetric geometry. The energy balance requires particular attention, as…
We have been analyzing a large sample of solar-like stars with and without planets in order to homogeneously measure their photospheric parameters and Carbon abundances. Our sample contains around 200 stars in the solar neighborhood…
Multiple radial velocity observations have been obtained for a large sample of local field subdwarf B (sdB) stars over a period of two years. SdB stars appear to fall into three distinct groups based on their kinematic and spectroscopic…
Binarity is often invoked to explain peculiarities that can not be explained by the standard theory of stellar evolution. Detecting orbital motion via the Doppler effect is the best method to test binarity when direct imaging is not…
The literature on the $\lambda$ Boo stars has grown to become somewhat heterogenous, as different authors have applied different criteria across the UV, optical and infrared regions to determine the membership status of $\lambda$ Boo…
In an effort to better understand the details of the stellar structure and evolution of metal poor stars, the Gemini North telescope was used on two occasions to take speckle imaging data of a sample of known spectroscopic binary stars and…
Binary stars constitute a large percentage of the stellar population, yet relatively little is known about the planetary systems orbiting them. Most constraints on circumbinary planets (CBPs) so far come from transit observations with the…
We develop a data-driven spectral model for identifying and characterizing spatially unresolved multiple-star systems and apply it to APOGEE DR13 spectra of main-sequence stars. Binaries and triples are identified as targets whose spectra…
Integrated spectrophotometric properties of stellar systems are intrinsically dispersed due to the stochastic nature of the small numbers of bright stars they contain. Among clusters, only the most massive ones can be used individually for…
A method is developed for fitting theoretically predicted astronomical spectra to an observed spectrum. Using a hierarchical Bayesian principle, the method takes both systematic and statistical measurement errors into account, which has not…
[ABRIDGED] AIMS: The MONOS project is collecting information and studying O-type spectroscopic binaries with delta > -20 deg. In this 2nd paper, we tackle the study of the 35 single-line spectroscopic binary (SB1) systems identified in the…
Aims. To search for these rare objects, we study 32 Galactic O-type stars that were reported as SB1s in the literature. In our sample we include Cyg X-1, which is known to host an accreting stellar-mass BH, and HD 74194, a supergiant fast…
The majority of planetary nebulae (PNe) are not spherical, and current single-star models cannot adequately explain all the morphologies we observe. This has led to the Binary Hypothesis, which states that PNe are preferentially formed by…