Related papers: Orbit Determination of Close Binary Systems using …

We report the results from a pilot study to search for black holes and other dark companions in binary systems using direct imaging with SHARK-VIS and the iLocater pathfinder "Lili" on the Large Binocular Telescope. Starting from known…

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…

Radial velocity measurements and simple sine-curve fits to the orbital velocity variations are presented for the third set of ten contact binary systems: CN And, HV Aqr, AO Cam, YY CrB, FU Dra, RZ Dra, UX Eri, RT LMi, V753 Mon, OU Ser. All…

We present higher-order multiplicity results for 60 solar-type spectroscopic binaries based on 0.75 micron imaging data taken by the Robotic Adaptive Optics system (Robo-AO) at the Kitt Peak 2.1m telescope. Our contrast curves show…

Spectra of composite systems (e.g., spectroscopic binaries) contain spatial information that can be retrieved by measuring the radial velocities (i.e., Doppler shifts) of the components in four observations with the slit rotated by 90…

In 2002, 2004, and 2017 we conducted high precision CCD photometry observations of the eclipsing binary system AS~Cam. By the analysis of the light curves from 1967 to 2017 (our data + data from the literature) we obtained photometric…

Using Monte Carlo simulations and published radial velocity surveys we have constrained the frequency and separation (a) distribution of very low mass star (VLM) and brown dwarf (BD) binary systems. We find that simple Gaussian extensions…

\rm Observations of close binary system (CBS) V1357 Cyg=Cyg X-1 in the $WBVR$ bands are reported. Photometry was carried out at the telescopes located in Kazakhstan, Uzbekistan and Crimea equipped with single-channel $WBVR$-photometer with…

We conducted a deep survey of resolved sub-systems among wide binaries with solar-type components within 67 pc from the Sun. Images of 61 stars in the K and H bands were obtained with the NICI adaptive-optics instrument on the 8-m…

M-dwarfs in extremely wide binary systems are very rare, and may thus have different formation processes from those found as single stars or close binaries in the field. In this paper we search for close companions to a new sample of 36…

We explored the regions within a radius of 25 arcsec around 473 nearby, low-metallicity G- to M-type stars using (VR)I optical filters and small-aperture telescopes. About 10% of the sample was searched up to angular separations of 90…

A large number of direct imaging surveys for exoplanets have been performed in recent years, yielding the first directly imaged planets and providing constraints on the prevalence and distribution of wide planetary systems. However, like…

Results of speckle interferometry observations at the 4.1 m SOuthern Astrophysical Research (SOAR) telescope obtained during 2024-2025 are presented. We present 5316 measurements of relative positions and magnitude differences in 3532 pairs…

We present 36 observations of 17 visual binaries of moderate separation (range from 0.15'' to 0.79'') made with the 50 cm Cassegrain telescope of the Jagiellonian University in Cracow. The speckle interferometry technique was combined with…

The speckle interferometry program at the the 4.1 m Southern Astrophysical Research Telescope (SOAR), started in 2008, now accumulated over 30,300 individual observations of 12,700 distinct targets. Its main goal is to monitor orbital…

We report the discovery of 14 low-mass binary systems containing mid-M to mid-L dwarf companions with separations larger than 250 AU. We also report the independent discovery of 9 other systems with similar characteristics that were…

We present results of the CFHT adaptive optics search for companions of a homogeneous group of contact binary stars, as a contribution to our attempts to prove a hypothesis that these binaries require a third star to become so close as…

Binary stars are prevalent yet challenging to detect. We present a novel approach using convolutional neural networks (CNNs) to identify binary stars from low-resolution spectra obtained by the LAMOST survey. The CNN is trained on a dataset…

We present the results of an adaptive optics survey for faint companions among Galactic O-type star systems (V < 8) using the Advanced Electro-Optical System (AEOS) 3.6-meter telescope on Haleakala. We surveyed these O star systems in…

Here we present an ensemble study of spin-orbit alignment in 51 close double star systems. We determine spin-orbit angles, obliquities, in 39 of these systems making use of recently improved apsidal motion rate measurements and apsidal…