Young stars in the UX Ori family (UXORs) demonstrate irregular brightness variability with varying degrees of depth and duration due to the specific orientation of their nearly edge-on discs with respect to the line of sight. It is supposed that a dusty screen located near the sublimation zone hides the star from the observer by rising above the plane of the disc. During such eclipses the spectrum of the star changes significantly, something that permits us to study both the nearest surroundings of the young star and the nature of the screening objects. The properties and features in the spectrum of UX Ori (a Herbig Ae star of spectral type A3III) have been considered in detail in our previous papers. Thanks to long-term observations with the Nordic Optical Telescope (NOT) we found evidence of a substantial change in the Hα line profile of UX Ori: from double-peaked when the star is in its bright state to single-peaked when in deep minimum. Using the spectra obtained during different brightness states we calculated models of the star's eclipses that can explain the behaviour of the Hα line. To solve the problem we calculated models of the emission regions in the nearest vicinity of the star, taking into consideration the zones of magnetospheric accretion and magneto-centrifugal disc wind, the radiation scattered on the circumstellar dust, and the extended disc wind beyond the dust sublimation radius. Line profiles were calculated for the star in its normal (bright) state, as well as during dust eclipses by introducing obscuring gas and dust screens at different positions. Our modelling reproduces well the observed Hα line profiles, and indicates that the transformation of the Hα line during eclipses is due to the action of two factors: a) by obscuring the emission of the magnetosphere of the star and that of the inner region of the disc wind with the dusty screen, and b) by increasing the contribution of the emission from the periphery zone beyond the screen into the total emission. The possibility of applying this model to other UXORs is discussed.

This study presents results of high-resolution spectroscopic observations of the star MWC 645, a representative of the poorly studied FS CMa-type objects. These stars are characterized by strong emission lines and significant infrared excess caused by circumstellar dust. For the first time, a cool secondary component has been detected in this system. Fundamental parameters were determined for both components: for the hot (B-type) star, an effective temperature of 18,000 ± 2000 K and luminosity log(L/L☉ ) = 3.9 ± 0.4; and for the cool (K-type) star, Teff = 4250 ± 250 K and log(L/L☉ ) = 3.1 ± 0.4. The system is located at a distance of 6.5 ± 0.9 kpc and shows clear signs of active interaction, including ongoing mass transfer indicated by the complex profiles of many emission lines. The results confirm the binary nature of MWC 645 and its classification as an FS CMa-type object. This work highlights the need for further observations to refine the system’s parameters and improve our understanding of the structure and origin of its circumstellar environment.

Abstract We present a comparative study of carbon-rich asymptotic giant branch (CAGB) stars in the Large Magellanic Cloud (LMC; 7347 stars) and the Milky Way (7163 stars) using infrared color–magnitude diagrams, spectral energy distributions (SEDs), two-color diagrams, and variability data. Observed SEDs are compared with theoretical models to characterize the central stars and their circumstellar dust envelopes and to estimate distances. For the LMC, a set of best-fitting CAGB models is derived by fitting observed SEDs with radiative transfer models, utilizing the galaxy’s well-established distance. For Galactic CAGB stars, where Gaia DR3 parallaxes are uncertain, we estimate distances by fitting observed SEDs with the CAGB models validated against LMC stars and for Mira variables, from the period–magnitude relation calibrated with LMC Miras. A comparison of these approaches demonstrates that the SED-based distances are both reliable and practical for a large sample of Galactic CAGB stars. We find that CAGB stars in both galaxies show broadly similar infrared properties, although the LMC sample lacks stars with extremely thick dust envelopes.

Amorphous silicate dust is a major component in the interstellar and circumstellar dust formed in the outflow of asymptotic giant branch (AGB) stars. Although iron depletion is observed in the interstellar medium, the exact form and fraction of iron in solids remains a matter of debate. In particular, it is unclear whether the amorphous silicate dust around AGB stars contains metallic iron. We aimed to provide optical constants of amorphous silicate nanoparticles and examine the effects of metallic iron on their spectral features to better constrain the dust properties. We did this by producing amorphous silicate nanoparticles with and without metallic cores. We performed condensation experiments using an induction thermal plasma system to produce dust analogs of the CI chondritic composition in Mg–Ca–Na–Al–Si–Fe–Ni–O and Mg–Ca–Na–Al–Si–O systems. We measured the absorbance and reflectance of the samples, observed the structure of the products, and determined the optical constants. Two types of amorphous silicate nanoparticles (ϕ 10-200 ) with nearly CI chondritic compositions were produced: one contained kamacite (Fe_0.9Ni_0.1) cores with a diameter ratio ranging from 0–0.87 (average 0.50), and the other was iron-free homogeneous amorphous silicate. The amorphous silicates of the CI chondritic composition with various-sized metallic cores may be prevalent in circumstellar and interstellar dust. , nm

We present late-time optical and infrared (IR) observations of a sample of nine extragalactic luminous red novae (LRNe) discovered in the past three decades. In all of these cases, the LRN survivors fade below the pre-outburst luminosity of the progenitors in the optical region. However, they remain visible in the near-IR (NIR) and bright in the mid-IR (MIR) domains for years. We recover AT 1997bs in images from 2004, and a residual source is visible in HST and JWST NIR images 27 years after the outburst. The spectral energy distribution (SED) of AT 1997bs is consistent with that of an orange giant star with a photospheric temperature of 3750-4250 K and a radius of 120-150 - Spitzer without a significant circumstellar dust attenuation. Similarly, the SED of AT 2019zhd after three years is compatible with a red supergiant star with T_ ph K and R $ colour curves extending up to more than 7 years for six LRNe, which show a similar evolution: The MIR colour is ∼-0.5 mag before the optical maximum light, it becomes bluer after around one year, and then it gradually turns to redder colours in the following years before reaching $ Another LRN, AT 2011kp, is detected by JWST 12.5 years after the outburst. Its SED, with two excesses at 1.8 and 7.7 μm, can be explained by a cold (T - K) dusty shell composed of amorphous carbon surrounding a cold expanded source, plus emission from the Paα line. We constructed the $ 3.6 4.5 3.6 4.5 ∼+1.0$ mag 7 years after the outburst. We also estimated the masses and the temperatures of newly formed dust years after the LRN onset. We find that LRNe produce dust masses of the order of (1-5) (and up to 2 between 7 and 13 years after the outbursts. Finally, we find that the remnants of LRNe detected years or decades after the merger tend to be expanded and cool objects, similar to red supergiant stars.

Abstract We have carried out a photometric time domain study of 188 intermediate-mass young stars observed in Full Frame Image mode with the Transiting Exoplanet Survey Satellite (TESS) satellite over the first 3.3 yr of its mission. The majority of these targets are classified as Herbig Ae/Be stars (HAeBes). All were monitored at optical wavelengths for at least one 27 day TESS sector, with many having multiple sectors of data. From a custom aperture photometry pipeline, we produced light curves and analyzed the variability therein, as a function of stellar and circumstellar properties. Based on visual and statistical analysis, we find that ∼95% of HAeBes are variable on timescales of 10 minutes to one month, with the most common light-curve morphology being stochastic. Approximately 15% of the set display quasiperiodic variability. In comparison to sets of low-mass T Tauri stars monitored with optical space telescopes, the Herbig Ae/Be stars display a much lower incidence of “dipper” behaviors (quasiperiodic or aperiodic fading events), as well as periodic modulations. As posited by previous work, we conclude that magnetic starspots are rare on HAeBes, and that the inner circumstellar dust rims of these objects lie at substantially larger radii than for low-mass young stars. Beyond these differences, the accretion dynamics of young stars less than ∼7 M ⊙ appear to be largely consistent based on their time domain properties from data streams of up to three months’ duration. We do, however, find tentative evidence for a change in variability amplitude above this mass boundary, particularly for quasiperiodic behavior.

Context. Mass loss in oxygen-rich asymptotic giant branch (AGB) stars remains a longstanding puzzle, as the dust species detected around these stars appear too transparent to drive winds through the absorption of radiation alone. The current paradigm consists of outflows driven by photon scattering and requires relatively large grains (∼0.3 μm). Whether the necessary number of grains with the required scattering properties exist around AGB stars remains to be determined empirically. Aims. We test whether the dust grains observed around the oxygen-rich AGB star R Doradus can drive its stellar wind by combining, for the first time, polarimetric constraints with elemental abundance limits and force balance calculations. We examine Fe-free silicates (MgSiO 3 ), aluminium oxide (Al 2 O 3 ), and Fe-bearing silicates (MgFeSiO 4 ) to determine whether any dust species can generate sufficient radiative pressure under physically realistic conditions. Methods. We analysed high-angular-resolution polarimetric observations obtained with SPHERE/ZIMPOL at the Very Large Telescope (VLT) and modelled the circumstellar dust using the radiative transfer code RADMC-3D. Dust optical properties were computed using Optool for both Mie and the distribution of hollow spheres (DHS) scattering theories. By systematically exploring a six-dimensional parameter space, we derived constraints on dust grain sizes, density profiles, and wavelength-dependent stellar radii. For models that successfully fit the observations, we analysed the results taking into consideration recent models for the gas density distribution around R Dor, and applied a multi-criteria zone analysis incorporating gas-depletion constraints and radiation pressure thresholds to assess dust-driven wind viability. Results. We find sub-micron MgSiO 3 and Al 2 O 3 grains (up to 0.1 μm) regardless of scattering theory considered, and a two-layer dust envelope with steep density profiles (r −3.4 to r −4.1 ). Despite matching observed scattered-light patterns, these grains generate insufficient radiative force under physically realistic gas-to-dust mass ratios, even when assuming complete elemental depletion. Silicates containing Fe could theoretically provide adequate force, but would sublimate in critical acceleration regions and require implausibly high silicon-depletion levels. Conclusions. Our findings for R Doradus show insufficient radiation pressure from scattering on grains, suggesting that dust alone cannot drive the wind in this star and that additional mechanisms may be required.

Abstract Emission in the wings of the H α line among late-type giant stars occurs as a consequence of conditions in their chromospheres. Data from the literature have been used to document the incidence of H α emission among Population I giant stars as a function of position in various color–magnitude diagrams (CMDs), including infrared versions that plot M K s versus ( J − K s ) and ( V − K s ). Population I and metal-poor Population II red giants are compared with regard to certain characteristics of H α emission. In the case of stars with emission, both observed photometry and photometry corrected for interstellar reddening are considered. Population I and II giants having H α emission are found to share a number of phenomena: (a) they occupy similar regions of the visual and infrared CMDs; (b) the emission in the blue and red wings is often of unequal strength, suggestive of mass motions in the chromosphere; (c) there are indications of time variability for a few stars that have been observed on multiple occasions; (d) red giants of both Population I and II having H α emission are often long-period or semiregular variables; and (e) a subset of them, but by no means all, evince circumstellar dust. While some giants with H α emission are pulsating red variables that have formed dusty circumstellar envelopes, others may be in prior phases of evolution where pulsations have commenced, which is restructuring the chromosphere and producing outflows, but has not yet generated the conditions needed for dust formation at higher circumstellar altitudes.

Abstract We present James Webb Space Telescope (JWST) Near-Infrared Camera (NIRCam) Br α , H 2 , [Fe ii ], and polycyclic aromatic hydrocarbon (PAH) imaging of the molecule-rich, high-excitation bipolar planetary nebula (PN) NGC 6537 (the Red Spider), complemented by new Atacama Large Millimeter/submillimeter Array (ALMA) and Chandra X-ray Observatory (Chandra) observations and archival Hubble Space Telescope (HST) images. The resulting multiwavelength view of the Red Spider establishes the detailed lobe–torus structure of the nebula and the mass-loss history of its progenitor star. The extinction-penetrating JWST/NIRCam Br α and PAH and ALMA 3 mm continuum imaging exposes the complexity of the ionized inner nebula. JWST/NIRCam H 2 imaging traces the full, ∼1.1 pc extent of the bubble-like lobes formed by fast (∼300–400 km s −1 ) polar outflows, while ALMA 13 CO(1–0) mapping reveals a point-symmetric, slowly (∼10 km s −1 ) expanding equatorial torus of radius ∼ 0.13 pc. In striking contrast, the [Fe ii ] image displays an extended S-shaped emission morphology that traces collisions between an active, collimated wind and slower-moving material along the lobe rims. No X-rays are detected from the nebula or its central star in deep Chandra/HRC-I imaging. However, the combined HST and JWST imaging reveals a near-IR excess at the central star indicative of emission from hot (∼1000 K) circumstellar dust. We propose that interactions between the nebular progenitor star and a close companion are responsible for the ejection of NGC 6537’s molecular torus, the formation of a circumbinary dust disk, and the launching of fast, wandering, collimated outflows that have inflated the polar lobe bubbles traced by near-IR H 2 emission and are presently generating the [Fe ii ]-emitting shocks.

IntroductionTraditionally, the condensation sequence of circumstellar dust is predicted based on the thermodynamic stabilities of specific condensates in the macroscopic bulk phase. However, at the (sub-) nanometer scale clusters with non-crystalline structures and significantly different properties are energetically favoured.MethodsFor this reason, we study the thermodynamic stabilities of metal oxide clusters with generic stoichiometries of M2O3 and M3O4, where M represents a metal atom. With an upper size limit of 50 atoms, we consider clusters with sizes n = 1–10 for (M2O3)n, and n = 1–7 for (M3O4)n. The M2O3 clusters comprise alumina (Al2O3), Mg-rich pyroxene (MgSiO3) and a size-limited sample of titanates (CaTiO3), whereas the M3O4 clusters include spinel (MgAl2O4), Mg-rich olivine (Mg2SiO4) and calcium aluminates (CaAl2O4).ResultsWe find that, apart from the alumina monomer, the aluminum-bearing clusters (Al2O3)n, n = 1–10, and (MgAl2O4)n, n = 1–7, are favoured over their silicate counterparts (MgSiO3)n, n = 1–10 and (Mg2SiO4)n, n = 1–7. Also, we find that calcium aluminate clusters, CaAl2O4, are energetically more favourable than magnesium aluminate clusters, MgAl2O4. Furthermore, for a limited data set of (CaTiO3)n, n = 1–2, clusters we find significantly larger stabilities than for the other considered (M2O3)n clusters, namely Al2O3 and MgSiO3.DiscussionFuture investigations, in particular on titanates and on Ca-rich silicates, are required to draw a more thorough and complete picture of the condensation sequence at the (sub-)nanoscale.

Luminous blue variables (LBVs) represent a brief transitional phase in the evolution of massive stars. Multi-wavelength studies of their circumstellar environments are essential to quantify their feedback at Galactic scales. Dominant emission mechanisms at millimetre wavelengths are, however, still poorly understood. Stellar winds, circumstellar dust, and ionised gas have not been explored together in the case of LBVs. We aim to study the millimetre continuum emission of Galactic LBVs to disclose the presence of these components, to describe their morphology, and to measure their relevance in the mass and energy injection to the interstellar medium. We used the NIKA2 continuum camera at the IRAM 30 m radio telescope to observe and analyse 1.15 and 2 mm continuum from the LBVs HD168607 HD168625 GKF2010 MN87 GKF2010 MN101 and G79.29+0.46 . We used the Virtual Observatory to complement our observations with archival data from optical, infrared, millimetre, and centimetre wavelengths. With this information, we built complete spectral energy distributions (SEDs) for the five sources that cover six decades of the electromagnetic spectrum. All targets except MN87 were detected at both wavelengths, with features including compact sources, extended nebular emission, shells, and unrelated background structures. The spectral indices of compact sources are consistent with thermal emission from stellar winds. We modelled the SEDs and successfully reproduced the emission from stellar photospheres, circumstellar dust, thermal stellar winds, and enshrouding Hii regions. Our models, in agreement with previous literature results, reveal unresolved hot dust very close to the stars and provide the first estimates for the fundamental parameters of MN101. This pilot study highlights the great potential of millimetre continuum studies of LBVs and possibly other evolved massive stars. The millimetre spectral window bridges the far-IR and radio regimes and can disclose the relative contribution of dust and free-free emission in this type of source.

Abstract We present follow-up imaging and spectroscopy and pre-explosion imaging of SN 2025pht located in NGC 1637 at 12 Mpc. Our spectroscopy shows that SN 2025pht is a Type II supernova (SN) with broad lines of hydrogen and with minimal line-of-sight extinction inferred from Na i D absorption. NGC 1637 was the target of several epochs of Hubble Space Telescope (HST) and James Webb Space Telescope (JWST) imaging covering the site of SN 2025pht from 31 to 0.7 yr prior to discovery. Using a follow-up HST image of SN 2025pht aligned to these data, we demonstrate that there is a credible progenitor candidate detected in multiple epochs of HST imaging and in JWST imaging from 1.3 to 8.7 μm, the first JWST counterpart to an SN and the longest-wavelength detection of an SN progenitor star. Fitting this source to red supergiant (RSG) spectral energy distributions (SEDs), we show that it is consistent with a log ( L / L ⊙ ) = 5.0 RSG heavily reddened by circumstellar dust. The JWST photometry enables strong constraints on the nature of the circumstellar medium, and we find that the SED favors graphite-rich dust as opposed to silicate-rich dust and an optical circumstellar extinction of A V = 5.3 mag. We discuss the implications of a pre-SN RSG enshrouded in carbon-rich dust and this finding for the overall population of progenitor stars to Type II SNe, as well as the future of SN progenitor star discovery with JWST.

Abstract This study presents a comparative analysis of mass-loss and dust production rates in the dwarf galaxies NGC 147 and NGC 185, focusing on long-period variables (LPVs) and pulsating asymptotic giant branch stars as primary indicators of dust feedback into the interstellar medium. For NGC 147, the total mass-loss rate is calculated as (9.44 ± 3.78) × 10−4 M ⊙ yr−1, with LPV luminosities ranging from (6.20 ± 0.25) × 102 L ⊙ to (7.87 ± 0.32) × 103 L ⊙. In NGC 185, the total mass-loss rate is higher, at (1.58 ± 0.63) × 10−3 M ⊙ yr−1, with LPV luminosities spanning (5.68 ± 0.23) × 102 L ⊙ to (1.54 ± 0.66) × 104 L ⊙. A positive correlation is observed between stellar luminosity, intrinsic reddening due to circumstellar dust self-extinction, and elevated mass-loss rates. Additionally, comparisons of calculated dust injection rates, two-dimensional dust distribution maps, and observed dust masses provide evidence for a gravitational interaction between NGC 147 and the Andromeda galaxy, which influences the dust distribution within the system.

Abstract Many mechanisms have been proposed to contribute to massive-star mass loss, but in general little is known about the physics involved. Studies of circumstellar environments around massive stars might help to determine which mechanisms are the most common. With the recent advent of high-contrast, extreme adaptive optics, coronagraphic instruments, direct-imaging studies of massive-star circumstellar environments have become possible. With these instruments, one can directly observe regions closer to the star than ever before. We performed a pilot study to image red supergiant circumstellar environments using the Gemini Planet Imager on Gemini South. In this paper, we report on the first direct detection of circumstellar dust around CD -31°4916, an otherwise “normal” red supergiant. This dust appears in both the near-infrared and the optical, which we obtained with follow-up HST observations. The dust appears to be at least partially located in clumps within 1″ of the central star. Therefore, we believe that continued exploration of massive star circumstellar environments with these coronagraphic instruments is warranted, even for systems with no previously resolved circumstellar material, and may play a vital role in our understanding of their mass-loss physics.

ABSTRACT White dwarf planetary systems uniquely link the bulk elemental composition of exoplanetary material to the mineralogy as photospheric abundances can be compared to circumstellar dust mineralogy. This study re-examines Spitzer/IRS spectra of eight white dwarfs with both circumstellar dust and photospheric metals. All systems show 10 $\mu$m silicate emission features consistent with a mixture of olivine and pyroxene silicates, with varying dominance. New Hubble Space Telescope ultraviolet spectroscopic observations of two of these systems, GD56 and WD 1150–153, reveal that both are accreting dry, rocky material. WD 1150–153 is accreting material consistent with Bulk Earth, while GD56 is accreting core-rich material with an inferred core mass fraction of 0.59$^{+0.08}_{-0.09}$ (0.37$^{+0.08}_{-0.08}$ by mole). A comparison between the bulk elemental composition of the accreted planetary material and the dust mineralogy of the eight systems reveals a tentative correlation between the dominant silicate mineralogy and the Mg/Si ratio, indicating that the circumstellar and photospheric material are compositionally similar. This suggests that rapid and well-mixed accretion is occurring with minimal compositional alteration. Furthermore, new ggchem equilibrium chemistry models confirm that Mg-rich planetary material preferentially forms olivine-rich dust, highlighting the importance of equilibrium in planetary chemistry and that a host star or rock’s Mg/Si can be used to predict whether its silicate mineralogy is olivine- or pyroxene-dominated, influencing its capacity to structurally store water, recycle key nutrients, and possibly habitability.

Abstract We report the discovery of a progenitor candidate for the Type IIb SN 2024abfo using multiepoch pre-explosion images from the Hubble Space Telescope and the Dark Energy Camera Legacy Survey. The progenitor exhibited a ∼0.7 mag decline in F814W from 2001 to 2013, followed by significant brightening and color fluctuations in the g, r, and z bands. This is the first time that substantial photometric variability has been found for the progenitor of a SN IIb. We suggest that the variability is caused by intrinsic changes in the progenitor star instead of varying obscuration by circumstellar dust. Our results show that the progenitor of SN 2024abfo was likely a yellow supergiant star with an initial mass of 12–18 M ⊙ for circumstellar reddening of E(B − V)CSM < 0.2 mag. Our study underscores the critical role of multiepoch imaging surveys in revealing the final stages of core-collapse supernovae progenitors.

Objects with the B[e] phenomenon, whose defining features are the presence of forbidden emission lines and infrared excess coming from circumstellar dust, represent a broad range of evolutionary stages from pre-main-sequence to planetary nebulae. They are important for understanding mechanisms of the circumstellar matter formation and evolution. However, it is not easy to discover them, especially among faint stars, as forbidden emission lines are usually weak and hardly noticeable in low-resolution spectra. We developed photometric criteria to search for candidate objects with this phenomenon based on a combination of optical and near-infrared color indices and found nearly 40 objects that satisfy these criteria. Spectroscopy of the candidates allows us to make more confident conclusions on their classification. We present the results of our photometric and spectroscopic observations of six objects, which are part of a large list of ∼40 objects that satisfy our photometric selection criteria for candidate objects with the B[e] phenomenon. Forbidden lines of neutral oxygen were clearly detected in the optical spectrum of one object (VES 683) and suspected in three others. One object, AS 415, is most likely a binary system with components that exhibit partial eclipses but without the B[e] phenomenon, while IRAS 20402 + 4638 may be a luminous member of the FS CMa objects group.

Herbig Ae/Be stars are young, pre-main-sequence stars that provide critical insights into the processes of stellar formation, early stellar evolution, and protoplanetary disks. Two key features of such stars are their circumstellar dusty disk and bipolar ionized outflows, which are critical components for understanding planet formation processes and the deposition of energy and/or matter in the interstellar medium, respectively. In this context, imaging polarimetry is arguably the most precise tool for characterizing the various structures and dynamics around the central star, due to the sensitivity of polarization to the morphology of the emitting, scattering, and absorbing media. We used previously unpublished, near-ultraviolet polarimetric data of LK-Hα-233 taken by the Faint Object Camera aboard the Hubble Space Telescope in 1991, 1994 and 1995, which remained archived despite their quality. Using the most recent and robust reduction pipeline for this instrument, we obtained high spatial resolution (0.0287 times 0.0287 arcsecond^2) maps of this object at 4118 Å, together with polarimetric measurements. A dark lane, bisecting the approaching and receding polar outflows, suggests the presence of a circumstellar disk or dust torus, which obscures the pre-main-sequence star and collimates the ejecta. Polarization reveals that the outflows have an X-shaped structure with a significant centrosymmetric pattern in the polarization angle, indicating that the outflows are both hollow and scatter the emission from the buried star. We constrain the half-opening angle of both the outflows and the circumstellar disk, determine the inclination of the system, and estimate the obscured star's intrinsic flux. This study highlights the importance of high-resolution polarimetric observations in understanding the complex environment around Herbig Ae/Be stars and advocates for future similar instruments.

Context. The Gaia mission discovered several hundred thousand long-period variables and measured parallaxes for many of them. These stars will allow us to study populations of variable stars in the Milky Way, including asymptotic giant branch (AGB) stars. Aims. This paper describes the identification of Gaia counterparts of a sample of oxygen-rich AGB stars with OH maser emission as a first step towards the compilation of a general Gaia Catalogue of Galactic AGB stars. With this catalogue, tests of evolutionary models for the AGB star population in the solar neighbourhood become feasible. Methods. We cross-matched AGB star candidates showing OH maser emission with the Gaia DR3 release using a cross-match with AllWISE and 2MASS as intermediate steps to avoid ambiguities. With the help of the Virtual Observatory, we retrieved photometric data from the near-ultraviolet to the far-infrared and built spectral energy distributions (SEDs) of the sources. The SEDs were fitted with theoretical models. The fit results, together with information from the literature, allowed us to clean the sample from non-AGB stars. For the AGB stars, bolometric fluxes were obtained. Distances based on Gaia parallaxes were used to derive the stellar luminosities. Results. We identified unique Gaia counterparts for 1487 OH masers. Of these, 1172 had an unambiguous classification as AGB stars. These sources make up the Gaia OH/IR star sample. Parallaxes with relative errors < 20% and astrometric excess noise < 1.5 mas were available for 222 OH/IR stars. Conclusions. The study of the AGB population in the solar neighbourhood is limited by the obscuration by circumstellar dust, as Gaia DR3 only provides parallaxes for a few of our candidates. The location of the OH/IR stars matches that of LPV discovered by Gaia in the (BP–RP; Gabs) diagram, but the OH/IR star sample is biased towards redder colours (BP–RP > 4) mag and larger amplitudes (> 1 mag in the G-band), which are typical for periodic large-amplitude Mira variables.

Abstract Circumstellar disk dust polarization in the (sub)millimeter is, for the most part, not from dust grain alignment with magnetic fields but rather indicative of a combination of dust self-scattering with a yet unknown alignment mechanism that is consistent with mechanical alignment. While the observational evidence for scattering has been well established, that for mechanical alignment is less so. Circum-multiple dust structures in protostellar systems provide a unique environment to probe different polarization alignment mechanisms. We present ALMA Band 4 and Band 7 polarization observations toward the multiple young system L1448 IRS3B. The polarization in the two bands are consistent with each other, presenting multiple polarization morphologies. On the size scale of the inner envelope surrounding the circum-multiple disk, the polarization is consistent with magnetic field dust grain alignment. On the very small scale of compact circumstellar regions, we see polarization that is consistent with scattering around source a and c, which are likely the most optically thick components. Finally, we see polarization that is consistent with mechanical alignment of dust grains along the spiral dust structures, which would suggest that the dust is tracing the relative gas flow along the spiral arms. If the gas-flow dust grain alignment mechanism is dominant in these cases, disk dust polarization may provide a direct probe of the small-scale kinematics of the gas flow relative to the dust grains.