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A strong and stable magnetic field covering the whole surface is a landmark of chemically peculiar or CP stars. To explain the origin of mag- netic stars, several hypotheses were proposed, which depending on the mech- anism and time of formation can be grouped into three main. The magnetic field may originate in the protostellar medium (“fossil field”), turbulent layers of a star (“dynamo” mechanism) or in the other environment. In either scenario, binary stars appear as a merit of its reliability. Recent advances in observational astrophysics uncovered a bunch of new binary magnetic stars that were considered as rare before. We outline the results of studies of exotic binary and multiple systems with magnetic CP components: HD 6757, HD 34736, and HD 40759.

We present the overview of an observational program carring out on the 6-m telescope of Special Astrophysical Observatory from 2012. This program aims the searches of new Bp stars with surface magnetic field and the detailed study of known magnetic CP star from the stellar association Ori OB1. HD 34736 is the most interesting star that was found as magnetic within the program recently.

We describe a flexible data reduction package for high resolution cross-dispersed echelle data. This open-source package is developed in Python and includes optional GUIs for most of the steps. It does not require any pre-knowledge about the form or position of the echelle-orders. It has been tested on cross-dispersed echelle spectrographs between 13k and 115k resolution (bifurcated fiber-fed spectrogaph ESO-HARPS and single fiber-fed spectrograph TNT-MRES). HiFLEx can be used to determine radial velocities and is designed to use the TERRA package but can also control the radial velocity packages such as CERES and SERVAL to perform the radial velocity analysis. Tests on HARPS data indicates radial velocities results within ±3 m s−1 of the literature pipelines without any fine tuning of extraction parameters.

We describe a flexible data reduction package for high resolution cross-dispersed echelle data. This open-source package is developed in Python and includes optional GUIs for most of the steps. It does not require any pre-knowledge about the form or position of the echelle-orders. It has been tested on cross-dispersed echelle spectrographs between 13k and 115k resolution (bifurcated fiber-fed spectrogaph ESO-HARPS and single fiber-fed spectrograph TNT-MRES). HiFLEx can be used to determine radial velocities and is designed to use the TERRA package but can also control the radial velocity packages such as CERES and SERVAL to perform the radial velocity analysis. Tests on HARPS data indicates radial velocities results within 3 m s−1 of the literature pipelines without any fine tuning of extraction parameters.

BINA-3 has been the third workshop of this series involving scientists from India and Belgium aimed at fostering future joint research in the view of cutting-edge observatories and advances in theory. BINA-3 was held at the Graphic Era Hill University, 22-24 March 2023 at Bhimtal (near Nainital), Uttarakhand, India. A major event was the inauguration of the International Liquid-Mirror Telescope (ILMT), the first liquid mirror telescope devoted exclusively to astronomy. BINA-3 provided impressive highlights encompassing topics of both general astrophysics and solar physics. Research results and future projects have been featured through invited and contributed talks, and poster presentations.

We summarise the results of a spectropolarimetric survey of 56 chemically peculiar (CP) stars in the association of Orion OB1. We uniformly collected the observational material with the 6-m telescope BTA of the Special Astrophysical Observatory in 2013-2021. We identify 14 new magnetic CP stars with a longitudinal magnetic field exceeding approximately 500 G. The studied sample contains 31 magnetic stars or 55% of the whole CP population in Orion OB1. We show that the percentage of the magnetic CP stars and the field strength drops sharply with age. The mean longitudinal magnetic field in the young subgroup OB1b (\\(\\log t=6.23\\)) is confidently almost three times stronger than in the older subgroups OB1a (\\(\\log t=7.05\\)) and OB1c (\\(\\log t=6.66\\)). In the Orion Nebula, a place with the youngest stellar population (\\(\\log t < 6.0\\)), we detect the magnetic field only in 20% of CP stars. Such occurrence drastically differs from 83% of magnetic CP stars in the nearby subgroup OB1c. We consider this effect an observational bias caused by a significant portion of a very young population with the signatures of Herbig Ae/Be stars. The technique we used for magnetic measurements, and the quality of available data do not allow us to detect weak fields in the case of stars with a limited number of lines and emissions in spectra.

The National Astronomical Research Institute of Thailand (NARIT) has a manifold network of small telescopes installed worldwide. These telescopes serve educational and research purposes and are equipped mainly with CCD detectors for direct imaging and photometry. To extend the possible field of applications, several telescopes were fitted with commercially available medium-resolution spectrographs eShel from Shelyak. With these devices, researchers in NARIT obtained a versatile tool for stellar spectroscopy. Here we describe the current status of available equipment, possible ways of upgrading, and briefly introduce the achieved results of the asteroseismologic study of fast-rotating stars.

We present and discuss medium resolution (R \\(\\sim\\) 13000), high signal-to-noise (\\(\\mathrm{\\frac{S}{N}} \\sim 100\\)), spectroscopic observations in the field of the open clusters NGC\\,6940 and Tombaugh\\,5. Spectra were recorded for seven candidate red giant stars in both clusters. For the latter we present the very first chemical abundance analysis. We derive radial velocities for all the stars in NGC\\,6940, confirming membership to the cluster for all of them, while on the same ground we exclude two stars in To\\,5. We perform a chemical abundance analysis of different atomic species, in particular FeI, SiI, CaI, TiI and NiI. The mean metallicity of NGC\\,6940 is [Fe/H]=+0.09\\(\\pm\\)0.06\\,dex, in good agreement with previous works, while for To\\,5 is [Fe/H]=+0.06\\(\\pm\\)0.11\\,dex. Therefore, both clusters exhibit a chemical composition close to the solar value, and do not deviate from the [Fe/H] Galactic radial abundance gradient. With these new values we estimate the fundamental cluster parameters, after having derived clusters' distances from the \\textit{Gaia} DR2 database. By adopting these distances, we derive updated estimated for the clusters ages: 1.0\\(\\pm\\)0.1\\,Gyr of NGC\\,6940 and 0.25\\(\\pm\\)0.05 Gyr for Tombaugh\\,5.

We present and discuss radial velocity and the very first metallicity measurements for nine evolved stars in the poorly known old open cluster NGC 7762. We isolated eight radial velocity cluster members and one interloper. Radial velocities are in good agreement with previous studies. NGC 7762 turns out to be of solar metallicity within the uncertainties ([Fe/H]=0.04\\(\\pm\\)0.12). For this metallicity, the cluster age is 2.5\\(\\pm\\)0.2 Gyr, and falls in a age range where only a few old open clusters are known. With respect to previous studies, we find a larger distance, implying the cluster to be located at 900\\(^{+70}_{-50}\\) pc from the Sun. For most of the elements we measure solar-scaled abundance ratios. We searched the literature for open clusters of similar age in the solar vicinity and found that NGC 7762 can be considered a twin of Ruprecht 147, a similar age cluster located at only 300 pc from the Sun. In fact, beside age, also metallicity and abundance ratios are very close to Ruprecht 147 values within the observational uncertainties.

We present the results of an asteroseismic study of HD 118660 (TIC 171729860), being a chemically peculiar (mild Am) star exhibiting \\(\\delta\\) Scuti (\\(\\delta\\) Sct) pulsations. It is based on the analysis of two sectors of time-series photometry from the space mission TESS and seismic modelling. It yielded the detection of 15 and 16 frequencies for TESS sectors 23 and 50, respectively. The identified pulsation modes include four radial (\\(\\ell=0\\)) and five dipolar (\\(\\ell=1\\)) ones. The radial modes are overtones with order \\(n\\) ranging from \\(3\\) and \\(6\\). Such high values of \\(n\\) are theoretically not expected for stars with the effective temperature of HD 118660 (\\(\\rm T_{\\rm eff}\\approx 7550 \\rm K\\) ) located near the red edge of the \\(\\delta\\) Sct instability strip. To estimate the asteroseismic parameters, we have generated a grid of stellar models assuming a solar metallicity (\\(Z=0.014\\)) and different values for the convective overshooting parameter (\\(0.1\\leq \\alpha_{\\rm ov}\\leq 0.3\\)). We conclude that the analysis of the radial modes is insufficient to constrain \\(\\alpha_{\\rm ov}\\) and \\(Z\\) for \\(\\delta\\) Sct stars. The value for the equatorial velocity of HD 118660 derived from the seismic radius and the rotational frequency is consistent with values found in the literature.