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In this contribution, we present the results from proper motion measurements across the Large Magellanic Cloud (LMC) using data from the VISTA survey of the Magellanic Cloud system (VMC). Using the derived proper motions, we modelled the structure of the LMC and analysed its internal kinematics. Within the central parts of the LMC, we found observational evidence for elongated orbits parallel to the bar’s major axis, which are considered to provide the main contribution for the support of a bar structure. A peculiar kinematic structure in the outer regions of the LMC hints toward stripped material from the Small Magellanic Cloud. We further introduce an observational campaign utilising the Hubble Space Telescope to precisely measure the proper motions of star clusters within the LMC. These motions, combined with radial velocities and 3D positions will be used to trace the gravitational potential of the LMC.

Detailed analysis of kinematics of the Milky Way disk in the solar neighborhood based on the GAIA DR3 catalog reveals the existence of peculiarities in the stellar velocity distribution perpendicular to the galactic plane. We study the influence of resonances—the outer Lindblad resonance and the outer vertical Lindblad resonance—of a rotating bar with stellar oscillations perpendicular to the plane of the disk, and their role in shaping the spatial and the velocity distributions of stars. We find that the Z and VZ distributions of stars with respect to LZ are affected by the outer Lindblad resonance. The existence of bar resonance with stellar oscillations perpendicular to the plane of the disk is demonstrated for a long (large semi-axis 5 kpc) and fast rotating bar with Ωb=60.0kms−1kpc−1. We show also that, in the model with the long and fast rotating bar, some stars in the 2:1 OLR region deviate far from their original places, entering the bar region. A combination of resonance excitation of stellar motions at the 2:1 OLR region together with strong interaction of the stars with the bar potential leads to the formation of the group of ‘escapees’, i.e., stars that deviate in R and Z—directions at large distances from the resonance region. Simulations, however, do not demonstrate any noticeable effect on VZ-distribution of stars in the solar neighborhood.

There are many intrinsic properties for the stars and some of them can be investigated by an astronomical way. Through an investigation on one Luyten’s star (LHS33), this paper presents one basic astronomical analysis method and result about its high proper motion, and brightness for four different filters (R C , V, Blue, I c ). It is an essential element when exploring the target star and obtaining its properties. The method used in this study is a measurement of astrometric position and photometry. All of the measurements require the original CCD (Charge-coupled Device) images obtained from the telescope and a series of software processing. The results obtained mainly are about the value of proper motion, apparent magnitude in these 4 filters above. For instance, the proper motion calculated for right ascension (RA) is 0.59 ± 0.10 arcsecs per year and for declination (Dec) is -3.70 ± 0.11 arcsecs per year. The valued calculations suggest an agreement with current published data. It verifies the correction for both operation procedure and data analysis. It gives a specific interpretation on why such the observation happened based on the quantitative analysis.

VERA has been regularly conducting astrometry of Galactic maser sources for ∼ 20 years, producing more than 100 measurements of parallaxes and proper motions of star-forming regions as well as AGB stars. By combining the observational results obtained by VLBA BeSSeL, EVN, and LBA, maser astrometry provides a unique opportunity to explore the fundamental structure of the Galaxy. Here we present the view of the Galaxy revealed by the maser astrometry, and also discuss the importance of maser astrometry in the era of GAIA by comparing the results obtained by VLBI and GAIA. We also present our view of “proper motions toward the future” of the relevant field, expected in the next decade based on global collaborations.

Actively accreting young stellar objects show H α emission line in their spectra. We present the results of survey for H α emission-line stars in the star-forming region IC 5070 taken with 2-m Himalyan Chandra Telescope. Based on the H α slitless spectroscopy data, we identified 131 emission-line stars in ∼ 0.29 square degrees area of the IC 5070 region. Using Gaia early data release 3, we estimated the mean proper motion and parallax of the emission-line stars. We also estimated the mean distance and reddening toward the region using the emission-line stars, which are ∼ 833 pc and ∼ 2 mag, respectively. By examining the locations of these stars in the color–magnitude diagrams constructed using Gaia and PanSTARRS1 data, we found that a majority of the H α emitters are young low-mass ( < 1.5 M ⊙ ) stars. We also compared our catalog of emission-line stars with the available young stellar catalogs and found that most of them are class  ii /flat spectrum sources with the spectral type ranging from K to M. Based on the proper motion/parallax values and locations on the color–magnitude diagrams, about 20 emission-line stars are flagged as non-members. The relative proper motion of the emission-line stars with respect to the ionizing source suggest the possibility of the ‘rocket effect’ scenario in the remnant cloud (BRC 31).

With the third data release of the Gaia mission, Gaia DR3 with its precise photometry and astrometry, it is now possible to study the behavior of stars at a scale never seen before. In this paper, we developed new criteria to identify T-Tauri stars (TTS) candidates using UV and optical color-magnitude diagrams (CMDs) by combining the GALEX and Gaia surveys. We found 19 TTS candidates and five of them are newly identified TTS in the Taurus molecular cloud (TMC), not cataloged before as TMC members. For some of the TTS candidates, we also obtained optical spectra from several Indian telescopes. We also present the analysis of distance and proper motion of young stars in the Taurus using data from Gaia DR3. We found that the stars in Taurus show a bimodal distribution with distance, having peaks at 130 . 17 - 1.24 1.31 pc and 156 . 25 - 5.00 1.86 pc. The reason for this bimodality, we think, is due to the fact that different clouds in the TMC region are at different distances. We further showed that the two populations have similar ages and proper motion distribution. Using the Gaia DR3 CMD, we showed that the age of Taurus is consistent with 1 Myr.

There is a new approach for the estimation of the position accuracy and proper motions of the stars in astrometric catalogues by comparison of the stars' positions in the researched and Hipparcos catalogues in different periods, but under a standard equinox. To verify this method was carried out the analysis of the star positions and proper motions UCAC2, PPM, ACRS, Tycho-2, ACT, TRC, FON and Tycho catalogues. As a result of this study was obtained that the accuracy of positions and proper motions of the stars in Tycho-2 and UCAC2 catalogues are approximately equal. The results of the comparison are represented graphically.

We use the RIOTS4 sample of SMC field OB stars to determine the origin of massive runaways in this low-metallicity galaxy using Gaia proper motions, together with stellar masses obtained from RIOTS4 data. These data allow us to estimate the relative contributions of stars accelerated by the dynamical ejection vs binary supernova mechanisms, since dynamical ejection favors faster, more massive runaways, while SN ejection favors the opposite trend. In addition, we use the frequencies of classical OBe stars, high-mass X-ray binaries, and non-compact binaries to discriminate between the mechanisms. Our results show that the dynamical mechanism dominates by a factor of 2 – 3. This also implies a significant contribution from two-step acceleration that occurs when dynamically ejected binaries are followed by SN kicks. We update our published quantitative results from Gaia DR2 proper motions with new data from DR3.

Based on the measurements performed in the first 14 months of Gaia operation, we have solved the problem of obtaining the systematic differences between the stellar positions and proper motions of the TGAS (Tycho–Gaia Astrometric Solution) and Tycho-2 catalogues. By dividing the common stars from the TGAS and Tycho-2 catalogues into three G -magnitude groups for mean values of 10 m ˙ 5 , 11 m ˙ 5 , a n d 13 m ˙ 0 , we have obtained the systematic differences between the stellar equatorial coordinates and proper motions of both catalogues in the form of a decomposition into vector spherical harmonics by taking into account the magnitude equation. The systematic components have been extracted from the individual differences with a probability of 0.977–0.999. The constructed model of systematic differences allows any position measurements performed using Tycho-2 as a reference catalogue to be transformed to the TGAS frame. An important fact is the existence of a magnitude equation in the systematic differences: when passing from bright ( G = 10 m ) to faint ( G = 13 m ) stars, the systematic position differences change within the range from approximately −40 to 15 mas, while the systematic proper motion differences change from −3 to 3 mas yr −1 . The orientation and mutual rotation parameters of the Tycho-2 and TGAS frames have also been found to be different for stars of different magnitudes: when passing from bright to faint stars, the rotation angle of the Tycho-2 frame relative to TGAS changes from 3.51 to 5.63 mas, while the angular velocity of rotation changes from 0.35 to 1.22 mas yr −1 . Based on the developed method that allows the extent to which the systematic errors in the equatorial propermotions of stars affect the results of a kinematic analysis of the Galactic proper motions to be estimated within the Ogorodnikov–Milne model, we have shown that the slope of the Galactic rotation curve and the Oort parameter C are most sensitive to the transition from the Tycho-2 frame to the TGAS one. Their relative changes after the transformation to the TGAS frame reach 56 and 100%, respectively. At the same time, the changes in the estimates of the Oort parameters A and B as well as the linear velocity of the Sun relative to the Galactic center, the Galactic rotation period, the ratio of the epicyclic frequency to the angular velocity of Galactic rotation, and the mass of the Galaxy within the Galactocentric distance of the Sun are not so large, being 2−10%.

The catalogue of protoplanetary nebulae by Vickers et al. has been supplemented with the line-of-sight velocities and proper motions of their central stars from the literature. Based on an exponential density distribution, we have estimated the vertical scale height from objects with an age less than 3 Gyr belonging to the Galactic thin disk (luminosities higher than 5000 L ⊙ ) to be h = 146 ± 15 pc, while from a sample of older objects (luminosities lower than 5000 L ⊙ ) it is h = 568 ± 42 pc. We have produced a list of 147 nebulae in which there are only the line-of-sight velocities for 55 nebulae, only the proper motions for 25 nebulae, and both line-of-sight velocities and proper motions for 67 nebulae. Based on this kinematic sample, we have estimated the Galactic rotation parameters and the residual velocity dispersions of protoplanetary nebulae as a function of their age. We have established that there is a good correlation between the kinematic properties of nebulae and their separation in luminosity proposed by Vickers. Most of the nebulae are shown to be involved in the Galactic rotation, with the circular rotation velocity at the solar distance being V 0 = 227 ± 23 km s −1 . The following principal semiaxes of the residual velocity dispersion ellipsoid have been found: (σ 1 , σ 2 , σ 3 ) = (47, 41, 29) km s −1 from a sample of young protoplanetary nebulae (with luminosities higher than 5000 L ⊙ ), (σ 1 , σ 2 , σ 3 ) = (50, 38, 28) km s −1 from a sample of older protoplanetary nebulae (with luminosities of 4000 L ⊙ or 3500 L ⊙ ), and (σ 1 , σ 2 , σ 3 ) = (91, 49, 36) km s −1 from a sample of halo nebulae (with luminosities of 1700 L ⊙ ).