Context. High-mass star formation remains a major open problem in astrophysics, particularly regarding the transition between deeply embedded protostars and the onset of ionising radiation capable of producing photodissociation regions (PDRs) and compact H II regions. Aims. We aim to characterise the excitation and ionisation conditions of the high-mass star-forming region IRAS 18162-2048, which is where the parsec-scale jet HH80-81 lies. Methods. We obtained adaptive optics-assisted integral field spectroscopy in the near-IR K band (1.93-2.47 & micro;m) with VLT/SINFONI, complemented by VLA X and C bands (3-6 cm) and ALMA band 3 (similar to 3.3 mm) observations. We analysed the continuum and line emission to derive visual extinction and excitation conditions and the kinematics of the gas of the region. Results. The near-IR continuum reveals two IR sources, IRS 2 and IRS 7, while the main protostellar core, IRAS 18162-2048, remains undetected up to 2.47 & micro;m. IRS 7 shows a peculiar hydrogen recombination line (HRL) Br gamma profile with a narrow emission component superimposed on a broad absorption feature, consistent with a B2/B3 zero-age main-sequence (ZAMS) star. Extended H-2 emission exhibits a 'sawtooth' pattern in the excitation diagram, characteristic of UV radiation in a PDR rather than shock excitation. The radiative transfer model Cloudy reproduces the H-2 ro-vibrational populations for T-gas = 600 K and n(H) = 7.9 & times; 10(3) cm(-3). The VLA X and C bands observations reveal a compact radio source previously reported as a 'stationary condensation' (SC) and coincident with IRS 7. For the first time, we detect IRS 7/SC in millimetre wavelengths. The spectral index in the 3-6 cm and 3.3 mm regime is consistent with optically thin free-free emission. Conclusions. Our near-IR and radio observations reveal that IRS 7/SC is a B2/B3 ZAMS star that has begun to photo-ionise its environment, giving rise to an extended PDR and a compact H II region. The coexistence of this source with the deeply embedded protostar IRAS 18162-2048 and other bubble-like structures in the field suggests a multi-generational star-forming environment. Future James Webb Space Telescope observations targeting the H-2 pure rotational lines (3-28 & micro;m) and other HRLs less affected by extinction will be essential to characterising the cooler molecular and ionised gas to fully disclose the formation history of the region.
The upcoming space missions that will characterize exoplanets, such as PLATO and Ariel, will collect huge amounts of data that will need to be complemented with ground-based observations. The aim of the PLATOSpec project is to perform science with an echelle spectrograph capable of measuring precise radial velocities. The main focus of the spectrograph will be to perform the initial screening and validation of exoplanetary candidates, in addition to study stellar variability. It will be possible to determine the physical properties of large exoplanets. The PLATOSpec blue-sensitive spectrograph, with a spectral range of 380-700 nm and a resolving power of R = 70.000 , is installed on the 1.5-m telescope at the ESO La Silla Observatory in Chile. Initial results show that the radial-velocity limit given by the wavelength calibration is about 2-3 m s(-1). Tests on bright F-K main-sequence standard stars reveal a scatter of about 5 m s(-1) over a few hours. The scatter over a few months is slightly higher. We demonstrate the capabilities of PLATOSpec on the mass determination of WASP-79 b and the spin-orbit alignment of WASP-62 b via the Rossiter-McLaughlin effect. We show its possible usage on variable star research as demonstrated on the false-positive exoplanetary candidate TIC 238060327, which is proven a binary star. Investigation of line-profile variations of the roAp star Cir shows that PLATOSpec can also be used for the surface mapping. Finally, we present new results on the active star UY Pic in the PLATO southern field. Our results show that PLATOSpec is a versatile spectrograph with great precision.
Small temperate planets are prime targets for exoplanet studies due to their possible similarities with the rocky planets in the Solar system. M dwarfs are promising hosts since the planetary signals are within our current detection capabilities. Gliese 12 b is a Venus-sized temperate planet orbiting a quiet M dwarf. We present here the first precise mass measurement of this small exoplanet. We performed a detailed analysis using HARPS-N (High Accuracy Radial velocity Planet Searcher for the Northern Hemisphere), ESPRESSO (Echelle Spectrograph for Rocky Exoplanets and Stable Spectroscopic Observations), and CARMENES (Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Echelle Spectrographs) radial velocities, along with new and archival TESS (Transiting Exoplanet Survey Satellite), CHEOPS (CHaracterising ExOPlanet Satellite), and MuSCAT2/3 (Multicolor Simultaneous Camera for studying Atmospheres of Transiting exoplanets) photometry data. From fitting the available data, we find that the planet has a radius of R-p = 0.93 +/- 0.06 R(circle plus )and a mass of M-p = 0.95(-0.30 )(+0.29)M(circle plus )(a3.2 sigma measurement of the semi-amplitude K = 0.67 +/- 0.21 m s(-1)), and is on an orbit with a period of 2.761418(-0.000055)(+0.000060)d. A variety of techniques were utilized to attenuate stellar activity signals. Gliese 12 b has an equilibrium temperature of T-eq = 317 +/- 8K, assuming an albedo of zero, and a density consistent with that of Earth and Venus (rho(p )= 6.4 +/- 2.4 g cm(-3)). We find that Gliese 12 b has a predominantly rocky interior and simulations indicate that it is unlikely to have retained any of its primordial gaseous envelope. The bulk properties of Gliese 12 b place it in an extremely sparsely populated region of both mass-radius and density-T-eq parameter space, making it a prime target for follow-up observations, including Lyman-alpha studies.
Accretion-driven outbursts are a fundamental process in star formation, determining the final masses of stars and the chemistry of protoplanetary disks, yet their detection in the youngest, deeply embedded protostars remains challenging. Radiatively pumped methanol masers, to date associated exclusively with high-mass young stellar objects, exhibit flares that are interpreted as signatures of accretion bursts and serve as beacons to identify massive protostellar outbursts. Indeed, for all such methanol maser flares studied thus far, the driving source has been identified as the associated high mass protostar. By combining James Webb Space Telescope (JWST) and Atacama Large Millimeter/submillimeter Array (ALMA) observations, we prove that the recent methanol maser flare in the massive star-forming region IRAS 18134-194216 was driven by a nearby lower-mass protostar undergoing a strong accretion outburst, rather than the central massive object. Our infrared spectroscopy captures the physical and chemical response of the protostellar core to the accretion burst. Our results demonstrate that methanol masers flares can uncover the hidden population of embedded low-mass bursting protostars in massive clusters, and challenge the standard paradigm where such maser activity is exclusively attributed to massive protostars, demonstrating that cavities opened by low-mass companions can provide a radiative path for triggering flares of pre-existing masers excited by massive protostars.
So far, the majority of high-resolution spectroscopy studies on exoplanet atmospheres have focused on transiting planetary systems. Consequently, the atmospheres of non-transiting exoplanets remain poorly explored, and the potential of high-resolution spectroscopy for determining key planetary parameters beyond their atmospheric properties has not been fully exploited. We obtained high-resolution emission spectra of the non-transiting hot Jupiter 51 Peg b in the K band with VLT/CRIRES+ to study its atmospheric thermochemical and dynamical structure and derive additional planetary parameters from the Doppler shift of its spectral lines. Using the cross-correlation technique, we confirmed the spectral signature of H2O in the planetary emission spectrum and a non-inverted atmospheric temperature profile. An indication was also found for the presence of atmospheric CO, although with a signal strength below the threshold for significant detection. The atmospheric chemical and thermal conditions were quantitatively constrained by use of a Bayesian retrieval framework, which yielded a high metallicity value (2.63(+0.93)(-1.00) dex) suggestive of chemical quenching, a solar C/O ratio (0.54(-0.23)(+0.18)), and a temperature profile in the upper atmosphere in line with the expected planetary equilibrium temperature. Moreover, we measured an excess of spectral line broadening, which suggests the presence of atmospheric dynamics in the atmosphere of 51 Peg b. The planetary signal was recovered at an orbital semi-amplitude of 102.8(-9.1)(+8.3) km s(-1), differing from previous high-resolution measurements. From the obtained orbital semi-amplitude, we further derived the surface gravity (3.15 +/- 0.12 log cgs), mass (0.61(-0.05)(+0.06) M-Jup), and orbital inclination (49.8(-5.7)(+5.8) deg) of 51 Peg b. The mass and inclination values differ from those reported in earlier works. Overall, this study provides new constraints on the thermochemical and dynamical properties of 51 Peg b's atmosphere and demonstrates the potential of high-resolution emission spectroscopy for measuring parameters related to the planetary orbital motion.
