The fate of massive stars during the latest stages of their evolution is highly dependent on their mass-loss rate and geometry. These processes have a significant influence on stars with masses between 25 and 40 Msun, i.e., type II SN progenitors. We aim to investigate the mass-loss history, geometry, and physical conditions of the yellow hypergiant in a post-RSG stage, IRAS 17163-3907. We place it in context with another famous yellow hypergiant, IRC+10420. We combine M-band high-resolution CRIRES+ spectroscopy with VLTI/MATISSE mid-infrared L-band interferometry, and FORS2 optical spectropolarimetry to probe both the small-scale circumstellar structure and the large-scale dusty environment of IRAS 17163. The CRIRES+ spectrum provides the first M-band coverage of IRAS 17163, revealing prominent low-excitation metal lines and hydrogen recombination features, but lacking the pronounced CO absorption seen in IRC+10420. The MATISSE observations reveal the first high angular scales of the source in the L-band and spatially resolve the Brα line-emitting region, which hints at a marginally asymmetric and variable ionised wind. FORS2 spectropolarimetry points to deviations from perfect spherical symmetry also on larger scales. The data show no evidence for a binary companion within the explored parameter space, indicating that the observed clumpy and time-variable mass loss is likely intrinsic to the star rather than companion-driven. Our results demonstrate that IRAS 17163 hosts a dense, structured, and time-variable wind, coexisting with extended dusty shells. The comparison with IRC+10420 highlights diversity among post-RSG YHGs. These findings emphasise the role of clumpy and near-symmetric mass-loss in shaping the circumstellar medium of evolved massive stars, with implications for their subsequent evolution and core-collapse supernova progenitor properties.

Context. The fate of massive stars during the latest stages of their evolution is highly dependent on their mass-loss rate and geometry. The geometry of the mass-loss process can be inferred from the shape of the circumstellar material, which has a significant influence on the evolution of massive stars (between 25 and 40 M⊙), i.e. type II SN progenitors. In this context, post-red supergiants (post-RSGs) offer an excellent opportunity to study mass-loss events. Aims. We aim to investigate the mass-loss history, geometry, and physical conditions of the yellow hypergiant in a post-RSG stage, IRAS 17163−3907 (IRAS 17163, also known as the ‘Fried Egg’ nebula). We place it in context with another famous evolved massive star, the yellow hypergiant IRC+10420. Methods. We combine M-band spectra of the source using high-resolution CRIRES+ spectroscopy, with VLTI/MATISSE mid-infrared interferometry in the L-band, and FORS2 optical spectropolarimetry to probe both the small-scale circumstellar structure and the large-scale dusty environment of IRAS 17163. The interferometric observables were analysed with simple geometric fitting and a more advanced parametric modelling using PMOIRED to extract the morphology of the hot inner shell that was previously reported via radiative transfer modelling. Results. The CRIRES+ spectrum provides the first M-band coverage of IRAS 17163, revealing prominent low-excitation metal lines and hydrogen recombination features, but lacking the pronounced CO absorption seen in IRC+10420. The MATISSE observations reveal the first high angular scales of the source in the L-band and spatially resolve the Brα line-emitting region, which is a factor of two more extended than the continuum emission and hints at a marginally asymmetric and variable ionised wind. FORS2 spectropolarimetry shows intrinsic continuum polarisation and line effects in the Stokes Q parameter across Hα, pointing to deviations from perfect spherical symmetry also on larger scales. The interferometry reveals no evidence for a binary companion within the explored parameter space, indicating that the observed clumpy and time-variable mass loss is likely intrinsic to the star rather than companion-driven. Conclusions. Our results demonstrate that IRAS 17163 hosts a dense, structured, and time-variable wind, coexisting with extended dusty shells. Comparison with IRC+10420 highlights the diversity among post-RSG yellow hypergiants, with IRAS 17163 showing an ionised environment without apparent molecular signatures. These findings emphasise the role of clumpy and near-symmetric mass loss in shaping the circumstellar medium of evolved massive stars, with implications for their subsequent evolution and core-collapse supernova progenitor properties.

While massive stars are frequently found in triple architectures, the lack of observed parameter distributions has long remained a bottleneck for statistical models of their evolution. We compile the first representative set of physical and orbital distributions for main-sequence hierarchical massive triples. We present a homogeneous analysis of 26 O-type hierarchical triples identified in the SMaSH+ survey by combining spectroscopic data for inner binaries with interferometric and aperture masking detections of tertiary companions within ∼200 au. We derive the distributions of masses, mass ratios, and separations, and investigate their joint probability density functions. We assess the dynamical stability of these systems and estimate the relative importance of secular processes by comparing the von Zeipel-Kozai-Lidov (ZKL) timescale to the general relativistic precession timescale for five systems with well-constrained orbital solutions. Finally, we evaluate the observational completeness. The sample is dominated by strongly hierarchical configurations, consisting primarily of tight inner spectroscopic binaries(a_in< 1 au) and wider tertiaries (a_out/a_in > 70 for most systems). We find no significant correlation between tertiary mass and either inner-binary mass or outer separation, indicating a broad diversity of system architectures. Ten systems host relatively massive tertiaries (q_out>0.5), especially at closer outer separations (a_out≲30 au). For two to four systems out of five, general relativistic precession dominates over ZKL oscillations in their current configuration. These results provide the first observationally grounded distributions of key parameters for massive hierarchical triples and offer important constraints for population synthesis and evolutionary models, particularly regarding the role of tertiary companions in shaping binary evolution.

The dynamics of the inner regions of young stellar objects (YSOs) is driven by a variety of physical phenomena, from magnetospheres and accretion to the dust sublimation rim and inner disk flows. These inner environments evolve on timescales of hours to days, exactly when bursts, dips, and rapid structural changes carry the most valuable information about star and planet formations, but remain hardly reachable with current facilities. A better reactive infrastructure with six or more telescopes, combined with alerts from large time-domain surveys (e.g., at the era of LSST/Rubin type facilities), and equipped with instruments spanning from the V-band to the thermal infrared (N), would provide the instantaneous uv-coverage and spectral diagnostics needed to unambiguously interpret and image these events as they happen. Such a world's first time-domain interferometric observatory would enable qualitatively new science: directly linking optical and infrared variability to spatially resolved changes in magnetospheric accretion, inner-disk geometry, and dust and gas dynamics in the innermost astronomical unit. Crucially, connecting these processes to outer-scale unresolved information from JWST, ALMA, and the ELT would yield a complete tomography of the planet-forming region.

Given the high incidence of binaries among mature field massive stars, it is clear that multiplicity is an inevitable outcome of high-mass star formation. Understanding how massive multiples form requires the study of the birth environments of massive stars, covering the innermost to outermost regions. We aim to detect and characterise low-mass companions around massive young stellar objects (MYSOs) during and shortly after their formation phase. To investigate large spatial scales, we carried out an $L'$-band high-contrast direct imaging survey seeking low-mass companions (down to $L_{\text{bol}}\approx 10 L_{\odot}$, or late A-type) around thirteen previously identified MYSOs using the VLT/NACO instrument. From those images, we looked for the presence of companions on a wide orbit, covering scales from 300 to 56,000 au. Detection limits were determined for all targets and we tested the gravitational binding to the central object based on chance projection probabilities. We have discovered a total of thirty-nine potential companions around eight MYSOs, the large majority of which have never been reported to date. We derived a multiplicity frequency (MF) of $62\pm13$% and a companion fraction (CF) of $3.0\pm0.5$. The derived MF and CF are compared to other studies for similar separation ranges. The comparisons are effective for a fixed evolutionary stage spanning a wide range of masses and vice versa. We find an increased MF and CF compared to the previous studies targeting MYSOs, showing that the statement in which multiplicity scales with primary mass also extends to younger evolutionary stages. The separations at which the companions are found and their location with relation to the primary star allow us to discuss the implications for the massive star formation theories.

Context. The inner parts of the hot discs surrounding massive young stellar objects (MYSOs) are still barely explored due to observational limitations in terms of angular resolution, scarcity of diagnostic lines, and the embedded and rare nature of these targets. Aims. We present the first K-band spectro-interferometric observations towards the MYSO G033.3891, which based on former kinematic evidence via the CO bandhead emission is known to host an accreting disc. Methods. Using the high spectral resolution mode (R similar to 4000) of the GRAVITY/VLTI, we spatially resolved the emission of the inner dusty disc and the crucial gaseous interface between the star and the dusty disc. Using detailed modelling on the K-band dust continuum and tracers known to be associated with the ionised and molecular gaseous interface (Br gamma, CO), we report on the smallest scales of accretion and ejection. Results. The new observations in combination with our geometric and kinematic models employed to fit former high spectral resolution observations on the source (R similar to 30 000; CRIRES/VLTI) allowed us to constrain the size of the inner gaseous disc both spatially and kinematically via the CO overtone emission at only 2 au. Our models reveal that both Br gamma and CO emissions are located well within the dust sublimation radius (5 au) as traced by the hot 2.2 mu m dust continuum. Conclusions. Our paper provides the first case study where the tiniest scales of gaseous accretion around the MYSO G033.3891 are probed both kinematically and spatially via the CO bandhead emission. This analysis of G033.3891 stands as only the second instance of such an investigation within MYSOs, underscoring the gradual accumulation of knowledge regarding how massive young stars gain their mass while further solidifying the disc nature of accretion at the smallest scales of MYSOs.

The inner parts of the hot discs surrounding massive young stellar objects (MYSOs) are still barely explored due to observational limitations in terms of angular resolution, scarcity of diagnostic lines and the embedded and rare nature of these targets. We present the first K-band spectro-interferometric observations toward the MYSO G033.3891, which based on former kinematic evidence via the CO bandhead emission is known to host an accreting disc. Using the high spectral resolution mode (R∼4000) of the GRAVITY/VLTI, we spatially resolve the emission of the inner dusty disc and the crucial gaseous interface between the star and the dusty disc. Using detailed modelling on the K-band dust continuum and tracers known to be associated with the ionised and molecular gaseous interface (Brγ, CO), we report on the smallest scales of accretion/ejection. The new observations in combination with our geometric and kinematic models employed to fit former high spectral resolution observations on the source (R∼30,000; CRIRES/VLTI) allow us to constrain the size of the inner gaseous disc both spatially and kinematically via the CO overtone emission at only 2 au. Our models reveal that both Brγ and CO emissions are located well within the dust sublimation radius (5 au) as traced by the hot 2.2 μm dust continuum. Our paper provides the first case study where the tiniest scales of gaseous accretion around the MYSO G033.3891 are probed both kinematically and spatially via the CO bandhead emission. This analysis of G033.3891 stands as only the second instance of such investigation within MYSOs, underscoring the gradual accumulation of knowledge regarding how massive young stars gain their mass, while further solidifying the disc nature of accretion at the smallest scales of MYSOs.

With steady observational advances, the formation of massive stars is being understood in more detail. Numerical models are converging on a scenario where accretion discs play a key role. Direct observational evidence of such discs at a few au scales is scarce, due to the rarity of such objects and the observational challenges, including the lack of adequate diagnostic lines in the near-IR. We present the analysis of K-band spectro-interferometric observations toward the Massive Young Stellar Object IRAS 13481-6124, which is known to host an accreting dusty disc. Using GRAVITY on the VLTI, we trace the crucial au-scales of the warm inner interface between the star and the accretion dusty disc. We detect and spatially resolve the Na i doublet and He i transitions towards an object of this class for the first time. The new observations in combination with our geometric models allowed us to probe the smallest au-scales of accretion/ejection around a MYSO. We find that Na i originates in the disc at smaller radii than the dust disc and is more compact than any of the other spatially resolved diagnostics (Br gamma, He i, and CO). Our findings suggest that Na i can be a new powerful diagnostic line in tracing the warm star/disc accreting interface of forming (massive) stars, while the similarities between He i and Br gamma point towards an accretion/ejection origin of He i.

With steady observational advances, the formation of massive stars is being understood in more detail. Numerical models are converging on a scenario where accretion discs play a key role. Direct observational evidence of such discs at a few au scales is scarce, due to the rarity of such objects and the observational challenges, including the lack of adequate diagnostic lines in the near-IR. We present the analysis of K-band spectro-interferometric observations toward the Massive Young Stellar Object IRAS 13481-6124, which is known to host an accreting dusty disc. Using GRAVITY on the VLTI, we trace the crucial au-scales of the warm inner interface between the star and the accretion dusty disc. We detect and spatially resolve the Na I doublet and He I transitions towards an object of this class for the first time. The new observations in combination with our geometric models allowed us to probe the smallest au-scales of accretion/ejection around an MYSO. We find that Na I originates in the disc at smaller radii than the dust disc and is more compact than any of the other spatially resolved diagnostics (Brγ, He I, and CO). Our findings suggest that Na I can be a new powerful diagnostic line in tracing the warm star/disc accreting interface of forming (massive) stars, while the similarities between He I and Brγ point towards an accretion/ejection origin of He I

Context. Previous studies have concluded that low- and intermediate-mass stars cannot account for the interstellar dust yield in the Magellanic Clouds inferred from far-infrared and sub-millimetre observations. Aims. Luminous blue variable stars (LBVs) form dust as a result of episodic, violent mass loss. To investigate their contribution as dust producers in the Magellanic Clouds, we analyse 31 confirmed and candidate LBVs from a recent census. Methods. We built a maximally complete multi-wavelength dataset of these sources from archival space telescope images and catalogues from near-infrared to millimetre wavelengths. We also present new Very Large Telescope VISIR observations of three sources in the Large Magellanic Cloud (LMC). We review the LBV classification on the basis of the infrared spectral energy distribution. To derive characteristic dust parameters, we fitted the photometry resulting from a stacking analysis, which consists of co-adding images of the same wavelength band of several targets to improve the signal-to-noise. For comparison we also stacked the images of low- and intermediate-mass evolved stars in the LMC. Results. We find four classes of sources: (1) LBVs showing mid-infrared dust emission plus near-infrared free-free emission from an ionised stellar wind (Class 1a) or only mid-infrared dust emission (Class 1b); (2) LBVs with a near-infrared excess due to free-free emission only (Class 2); (3) objects with an sgB[e] classification in the literature, displaying a distinctive hot dust component; and (4) objects with no detected stellar winds and no circumstellar matter in their SEDs. From the stacking analysis of the 18 Class 1 and 2 objects in the LMC, we derived an integrated dust mass of 0.11−0.03+0.06 M⊙. This is two orders of magnitude larger than the value inferred from stacking 1342 extreme-asymptotic giant branch stars. The dust mass of individual LBVs does not correlate with the stellar parameters, possibly suggesting that the dust production mechanism is independent of the initial stellar mass or that the stars have different evolutionary histories. The total dust yield from LBVs over the age of the LMC is ∼104 − 105 M⊙. The one order of magnitude uncertainty is mainly due to uncertainties of the LBV population, star formation history, and initial mass function. Conclusions. LBVs are potentially the second most important source of dust in normal galaxies. The role of dust destruction in LBV nebulae by a possible subsequent supernova (SN) blast wave has yet to be determined. Recent theoretical developments in the field of dust processing by SN shocks highlight the potential survival of dust grains from the pre-existing circumstellar nebula.

Luminous blue variable stars (LBVs) are of great interest in massive-star evolution as they experience very high mass-loss episodes within short periods of time. HR Car is a famous member of this class in the Galaxy. It has a large circumstellar nebula and has also been confirmed as being in a binary system. One means of gaining information about the evolutionary status and physical nature of LBVs is studying their environments. We investigated the stellar content within ~100 pc of HR Car and also its circumstellar nebula. Very Large Telescope (VLT) Multi Unit Spectroscopic Explorer (MUSE) observations of a 2'x2' region around the star highlight the incompleteness of stellar classification for stars with magnitudes of V > 13 mag. Eight B0 to B9 stars have been identified which may lie in close spatial vicinity to HR Car. For a region with a radius of r =1.2 degree (~100 pc at a distance of 4.8 kpc) around HR Car, existing catalogs list several late O-type and early B-type stars, but only one early O-type star. Given the relatively low stellar and nebular masses in the HR Car system, no early O-type stars and only a few late O-type stars would be expected in association with HR Car. Instead, HR Car's location in a point vector diagram suggests that HR Car is not isolated, but is part of a moving group with a population of B-type stars in a spiral arm, and it has not received a strong kick from a supernova explosion of a companion star or a merger event. Potential binary evolution pathways for the HR Car system cannot be fully explored because of the unknown nature of the companion star. Furthermore, the MUSE observations reveal the presence of a fast outflow and "bullets" that have been ejected at intervals of about 400 years. These features may have been caused by recurrent mass transfer in the system.

The rarity and deeply embedded nature of stars with masses larger than 8 solar masses has limited our understanding of their formation. Previous work has shown that complementing spectral energy distributions with interferometric and imaging data can probe the circumstellar environments of massive young stellar objects (MYSOs) well. However, complex studies of single objects often use different approaches in their analysis. Therefore the results of these studies cannot be directly compared. This work aims to obtain the physical characteristics of a sample of MYSOs at 0.01" scales, at 0.1" scales, and as a whole, which enables us to compare the characteristics of the sources. We apply the same multi-scale method and analysis to a sample of MYSOs. High-resolution interferometric data, near-diffraction-limited imaging data, and a multi-wavelength spectral energy distribution are combined. By fitting simulated observables derived from 2.5D radiative transfer models of disk-outflow-envelope systems to our observations, the properties of the MYSOs are constrained. We find that the observables of all the MYSOs can be reproduced by models with disk-outflow-envelope geometries, analogous to the Class I geometry associated with low-mass protostars. The characteristics of the envelopes and the cavities within them are very similar across our sample. On the other hand, the disks seem to differ between the objects, in particular with regards to what we interpret as evidence of complex structures and inner holes. This is comparable to the morphologies observed for low-mass young stellar objects. A strong correlation is found between the luminosity of the central MYSO and the size of the transition disk-like inner hole for the MYSOs, implying that photoevaporation or the presence of binary companions may be the cause.

Context. It has been hypothesized that the location of Herbig Ae/Be stars (HAeBes) within the empirical relation between the inner disk radius (r in ), inferred from K -band interferometry, and the stellar luminosity (L * ), is related to the presence of the innermost gas, the disk-to-star accretion mechanism, the dust disk properties inferred from the spectral energy distributions (SEDs), or a combination of these effects. However, no general observational confirmation has been provided to date.Aims. This work aims to test whether the previously proposed hypotheses do, in fact, serve as a general explanation for the distribution of HAeBes in the size–luminosity diagram.Methods. GRAVITY/VLTI spectro-interferometric observations at ~2.2 μm have been obtained for five HBes representing two extreme cases concerning the presence of innermost gas and accretion modes. V590 Mon, PDS 281, and HD 94509 show no excess in the near-ultraviolet, Balmer region of the spectra (ΔD B ), indicative of a negligible amount of inner gas and disk-to-star accretion, whereas DG Cir and HD 141926 show such strong ΔD B values that cannot be reproduced from magnetospheric accretion, but probably come from the alternative boundary layer mechanism. In turn, the sample includes three Group I and two Group II stars based on the Meeus et al. SED classification scheme. Additional data for these and all HAeBes resolved through K -band interferometry have been compiled from the literature and updated using Gaia EDR3 distances, almost doubling previous samples used to analyze the size–luminosity relation.Results. We find no general trend linking the presence of gas inside the dust destruction radius or the accretion mechanism with the location of HAeBes in the size–luminosity diagram. Similarly, our data do not support the more recent hypothesis linking such a location and the SED groups. Underlying trends are present and must be taken into account when interpreting the size–luminosity correlation. In particular, it cannot be statistically ruled out that this correlation is affected by dependencies of both L * and r in on the wide range of distances to the sources. Still, it is argued that the size–luminosity correlation is most likely to be physically relevant in spite of the previous statistical warning concerning dependencies on distance.Conclusions. Different observational approaches have been used to test the main scenarios proposed to explain the scatter of locations of HAeBes in the size–luminosity diagram. However, none of these scenarios have been confirmed as a fitting general explanation and this issue remains an open question.

Context. Eta Carinae is a highly eccentric, massive binary system (semimajor axis ~15.5 au) with powerful stellar winds and a phase-dependent wind-wind collision (WWC) zone. The primary star, η Car A, is a luminous blue variable (LBV); the secondary, η Car B, is a Wolf-Rayet or O star with a faster but less dense wind. Aperture-synthesis imaging allows us to study the mass loss from the enigmatic LBV η Car. Understanding LBVs is a crucial step toward improving our knowledge about massive stars and their evolution. Aims. Our aim is to study the intensity distribution and kinematics of η Car’s WWC zone. Methods. Using the VLTI-MATISSE mid-infrared interferometry instrument, we perform Br α imaging of η Car’s distorted wind. Results. We present the first VLTI-MATISSE aperture-synthesis images of η Car A’s stellar windin several spectral channels distributed across the Br α 4.052 μm line (spectral resolving power R ~ 960). Our observations were performed close to periastron passage in February 2020 (orbital phase ~ 14.0022). The reconstructed iso-velocity images show the dependence of the primary stellar wind on wavelength or line-of-sight (LOS) velocity with a spatial resolution of 6 mas (~14 au). The radius of the faintest outer wind regions is ~26 mas (~60 au). At several negative LOS velocities, the primary stellar wind is less extended to the northwest than in other directions. This asymmetry is most likely caused by the WWC. Therefore, we see both the velocity field of the undisturbed primary wind and the WWC cavity. In continuum spectral channels, the primary star wind is more compact than in line channels. A fit of the observed continuum visibilities with the visibilities of a stellar wind CMFGEN model (CMFGEN is an atmosphere code developed to model the spectra of a variety of objects) provides a full width at half maximum fit diameter of the primary stellar wind of 2.84 ± 0.06 mas (6.54 ± 0.14 au). We comparethe derived intensity distributions with the CMFGEN stellar wind model and hydrodynamic WWC models.

Young massive stars influence their surroundings from local to galactic scales, but the observational challenges associated with their distance and embedded nature has, until the recent decade, made high-resolution studies of these objects difficult. In particular, comparative analyses of massive young stellar object (MYSO) disks are currently lacking and our understanding of their evolution is limited. Here, we combine the results of two studies with the aim to attribute geometrical features to an evolutionary sequence for a sample of seven MYSOs. The time evolution is based on near-infrared spectral features, while the geometry is determined from a multi-size-scale study of MYSOs. We find that MYSO disks with determined geometrical substructure turn out to be also spectroscopically more evolved. This implies that disk evolution and dispersal occur within MYSOs similarly to low-mass young stellar object (YSO) disk evolution, despite their faster formation timescales.

Circumstellar discs are essential for high mass star formation, while multiplicity, in particular binarity, appears to be an inevitable outcome since the vast majority of massive stars (> 8 Msun) are found in binaries (up to 100%). We constrain the sizes of the dust and ionised gas (Brgamma) emission of the innermost regions towards a sample of six MYSOs, and provide high-mass binary statistics of young stars at 2-300 au scales using VLTI (GRAVITY, AMBER) observations. We determine the inner radius of the dust emission and place MYSOs with K-band measurements in a size-luminosity diagram for the first time, and compare our findings to T Tauris and Herbig AeBes. We also compare the observed K-band sizes to the sublimation radius predicted by three different disc scenarios. Lastly, we apply binary geometries to trace close binarity among MYSOs. The inner sizes of MYSOs, Herbig AeBe and T Tauri stars appear to follow a universal trend at which the sizes scale with the square-root of the stellar luminosity. The Brgamma emission originates from somewhat smaller and co-planar area compared to the 2.2 {\mu}m continuum emission. We discuss this new finding with respect to disc-wind or jet origin. Finally, we report an MYSO binary fraction of 17-25% at milli-arcsecond separations (2-300 au). The size-luminosity diagram indicates that the inner regions of discs around young stars scale with luminosity independently of the stellar mass. At the targeted scales (2-300 au), the MYSO binary fraction is lower than what was previously reported for the more evolved main sequence massive stars, which, if further confirmed, could implicate the predictions from massive binary formation theories. Lastly, we spatially resolve the crucial star/disc interface in a sample of MYSOs, showing that au-scale discs are prominent in high-mass star formation and similar to their low-mass equivalents.

Context. The rarity of young massive stars combined with the fact that they are often deeply embedded has limited the understanding of the formation of stars larger than 8M(circle dot). Ground based mid-infrared (IR) interferometry is one way of securing the spatial resolution required to probe the circumstellar environments of massive young stellar objects (MYSOs). Given that the spatial-frequency coverage of such observations is often incomplete, direct-imaging can be supplementary to such a dataset. By consolidating these observations with modelling, the features of a massive protostellar environment can be constrained. Aims. This paper aims to detail the physical characteristics of the protostellar environment of the MYSO G305.20+0.21 at three size-scales by fitting one 2.5D radiative transfer model to three different types of observations simultaneously, providing an extensive view of the accreting regions of the MYSO. Methods. Interferometry, imaging and a multi-wavelength spectral energy distribution (SED) are combined to study G305.20+0.21. The high-resolution observations were obtained using the Very Large Telescope's MIDI and VISIR instruments, producing visibilities in the N-band and near-diffraction-limited imaging in the Q-band respectively. By fitting simulated observables, derived from the radiative transfer model, to our observations the properties of the MYSO are constrained. Results. The VISIR image shows elongation at 100 mas scales and also displays a degree of asymmetry. From the simulated observables derived from the radiative transfer model output we find that a central protostar with a luminosity of similar to 5 x 10(4) L-circle dot surrounded by a low-density bipolar cavity, a flared 1M(circle dot) disk and an envelope is sufficient to fit all three types of observational data for G305.20+0.21. The weak silicate absorption feature within the SED requires low-density envelope cavities to be successfully fit and is an atypical characteristic in comparison to previously studied MYSOs. Conclusions. The fact that the presence of a dusty disk provides the best fit to the MIDI visibilities implies that this MYSO is following a scaled-up version of the low-mass star formation process. The low density, low extinction environment implies the object is a more evolved MYSO and this combined with large inner radius of the disk suggests that it could be an example of a transitional disk around an MYSO.