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Denis, A., Janson, M. & Zins, G. (2025). Characterization of AF Lep b at high spectral resolution with VLT/HiRISE. Astronomy and Astrophysics, 696, Article ID A6.
Open this publication in new window or tab >>Characterization of AF Lep b at high spectral resolution with VLT/HiRISE
2025 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 696, article id A6Article in journal (Refereed) Published
Abstract [en]

Context. Since the recent discovery of the directly imaged super-Jovian planet AF Lep b, several studies have been conducted to characterize its atmosphere and constrain its orbital parameters. AF Lep b has a measured dynamical mass of 3.68 ± 0.48 MJup, radius of 1.3 ± 0.15 RJup, nearly circular orbit in spin-orbit alignment with the host star, relatively high metallicity, and near-solar to super-solar C/O ratio. However, key parameters such as the rotational velocity and radial velocity have not been estimated thus far, as they require high-resolution spectroscopic data that are impossible to obtain with classical spectrographs. Aims. AF Lep b was recently observed with the new HiRISE visitor instrument at the VLT, with the goal of obtaining high-resolution (R ≈ 140 000) spectroscopic observations to better constrain the orbital and atmospheric parameters of the young giant exoplanet. Methods. We compared the extracted spectrum of AF Lep b to self-consistent atmospheric models using ForMoSA, a forward modeling tool based on Bayesian inference methods. We used our measurements of the planet's radial velocity to offer new constraints on its orbit. Results. From the forward modeling, we find a C/O ratio that aligns with previous low-resolution analyses and we confirm its supersolar metallicity. We also unambiguously confirm the presence of methane in the atmosphere of the companion. Based on all available relative astrometry and radial velocity measurements of the host star, we show that two distinct orbital populations are possible for the companion. We derived the radial velocity of AF Lep b to be 10.51 ± 1.03 km s-1 and show that this value is in good agreement with one of the two orbital solutions, allowing us to rule out an entire family of orbits. Additionally, assuming that the rotation and orbit are coplanar, the derived planet's rotation rate is consistent with the observed trend of increasing spin velocity with higher planet mass.

Keywords
Instrumentation: high angular resolution, Instrumentation: spectrographs, Planets and satellites: atmospheres, Planets and satellites: formation, Techniques: imaging spectroscopy
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:su:diva-243012 (URN)10.1051/0004-6361/202453108 (DOI)001457370100004 ()2-s2.0-105001832490 (Scopus ID)
Available from: 2025-05-08 Created: 2025-05-08 Last updated: 2025-05-08Bibliographically approved
Janson, M., Wehrung-Montpezat, J., Wehrhahn, A., Brandeker, A., Viswanath, G., Mollière, P. & Stolker, T. (2025). Deep high-resolution L band spectroscopy in the β Pictoris planetary system. Astronomy and Astrophysics, 694, Article ID A63.
Open this publication in new window or tab >>Deep high-resolution L band spectroscopy in the β Pictoris planetary system
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2025 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 694, article id A63Article in journal (Refereed) Published
Abstract [en]

The β Pictoris system, with its two directly imaged planets β Pic b and β Pic c and its well characterised debris disk, is a prime target for detailed characterisation of young planetary systems. Here, we present high-resolution and high-contrast LM band spectroscopy with CRIRES+ of the system, primarily for the purpose of atmospheric characterisation of β Pic b. We developed methods for determining slit geometry and wavelength calibration based on telluric absorption and emission lines, as well as methods for point spread function (PSF) modelling and subtraction, and artificial planet injection, in order to extract and characterise planet spectra at a high signal-to-noise ratio (S/N) and spectral fidelity. Through cross-correlation with model spectra, we detected H2O absorption for planet b in each of the 13 individual observations spanning four different spectral settings. This provides a clear confirmation of previously detected water absorption, and allowed us to derive an exquisite precision on the rotational velocity of β Pic b, ÏÂ rot = 20.36 ± 0.31 km/s, which is consistent within error bars with previous determinations. We also observed a tentative H2O cross-correlation peak at the expected position and velocity of planet c; the feature is however not at a statistically significant level. Despite a higher sensitivity to SiO than earlier studies, we do not confirm a tentative SiO feature previously reported for planet b. When combining data from different epochs and different observing modes for the strong H2O feature of planet b, we find that the S/N grows considerably faster when sets of different spectral settings are combined, compared to when multiple data sets of the same spectral setting are combined. This implies that maximising spectral coverage is often more important than maximising integration depth when investigating exoplanetary atmospheres using cross-correlation techniques.

Keywords
Planetary systems, Planets and satellites: atmospheres, Techniques: spectroscopic
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:su:diva-239868 (URN)10.1051/0004-6361/202452411 (DOI)001414753300021 ()2-s2.0-85217480356 (Scopus ID)
Available from: 2025-02-26 Created: 2025-02-26 Last updated: 2025-02-26Bibliographically approved
Thompson, W., Blakely, D., Xuan, J. W., Bouchard-Côté, A., Bourdarot, G., Biron-Lattes, M., . . . Winterhalder, T. (2025). On the Orbit of the Binary Brown Dwarf Companion GL229 Ba and Bb. Astronomical Journal, 169(4), Article ID 193.
Open this publication in new window or tab >>On the Orbit of the Binary Brown Dwarf Companion GL229 Ba and Bb
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2025 (English)In: Astronomical Journal, ISSN 0004-6256, E-ISSN 1538-3881, Vol. 169, no 4, article id 193Article in journal (Refereed) Published
Abstract [en]

The companion GL229B was recently resolved by Xuan et al. as a tight binary of two brown dwarfs (Ba and Bb) through VLTI-GRAVITY interferometry and Very Large Telescope-CRIRES+ radial velocity (RV) measurements. Here, we present Bayesian models of the interferometric and RV data in additional detail, along with an updated outer orbit of the brown dwarf pair about the primary. To create a model of the inner orbit with robust uncertainties, we apply kernel phases to the GRAVITY data, to address baseline redundancy in the raw closure phases. Using parallel tempering, we constrain the binary’s orbit using only VLTI-GRAVITY data, despite each epoch having low visibility-plane coverage and/or signal-to-noise ratio (SNR). We demonstrate very good agreement between the VLTI-GRAVITY and CRIRES+ data sets and find that the inner binary has a period of 12.1346 ± 0.0011 days, an eccentricity of 0.2317 ± 0.0025, and a total mass of 71.0 ± 0.4 Mjup, with Ba and Bb having masses of 37.7 ± 1.1 Mjup and 33.4 ± 1.0Mjup, respectively. With new Keck/NIRC2 astrometry, we update the outer orbit of GL229B around the primary. We find a semimajor axis of 42.9+3.0-2.4 au, an eccentricity of 0.736 ± 0.014, and a total mass for B of 71.7 ± 0.6 Mjup, consistent with that derived from the inner orbit. We find a mutual inclination of 31° ± 2 . ° 5, below the threshold for Kozai-Lidov oscillations. The agreement on the mass of Ba+Bb between the inner and outer orbits is an important test of our ability to model the RV, astrometry, and Hipparcos-Gaia proper-motion anomaly. Our methodological advances in handling interferometric data with low SNR and sparse UV coverage will benefit future observations of rapidly orbiting companions with VLTI-GRAVITY.

National Category
Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:su:diva-241865 (URN)10.3847/1538-3881/adb4f2 (DOI)001438595600001 ()2-s2.0-86000759195 (Scopus ID)
Available from: 2025-04-09 Created: 2025-04-09 Last updated: 2025-04-09Bibliographically approved
Janson, M. (2025). The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems. III. Aperture Masking Interferometric Observations of the Star HIP 65426 at 3.8 μm. Astrophysical Journal Letters, 983(1), Article ID L25.
Open this publication in new window or tab >>The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems. III. Aperture Masking Interferometric Observations of the Star HIP 65426 at 3.8 μm
2025 (English)In: Astrophysical Journal Letters, ISSN 2041-8205, E-ISSN 2041-8213, Vol. 983, no 1, article id L25Article in journal (Refereed) Published
Abstract [en]

We present aperture masking interferometry (AMI) observations of the star HIP 65426 at 3.8 μm, as part of the JWST Direct Imaging Early Release Science program, obtained using the Near Infrared Imager and Slitless Spectrograph instrument. This mode provides access to very small inner working angles (even separations slightly below the Michelson limit of 0.5λ/D for an interferometer), which are inaccessible with the classical inner working angles of the JWST coronagraphs. When combined with JWST's unprecedented infrared sensitivity, this mode has the potential to probe a new portion of parameter space across a wide array of astronomical observations. Using this mode, we are able to achieve a 5σ contrast of ΔmF380M ∼ 7.62 ± 0.13 mag relative to the host star at separations ​​​​​≳0.″07, and the contrast deteriorates steeply at separations ≲0.″07. However, we detect no additional companions interior to the known companion HIP 65426b (at separation ∼0.″82 or 87−31+108au). Our observations thus rule out companions more massive than 10–12 MJup at separations ∼10–20 au from HIP 65426, a region out of reach of ground- or space-based coronagraphic imaging. These observations confirm that the AMI mode on JWST is sensitive to planetary mass companions at close-in separations (≳0.″07), even for thousands of more distant stars at ∼100 pc, in addition to the stars in the nearby young moving groups and associations, as stated in previous works. This result will allow the planning and successful execution of future observations to probe the inner regions of nearby stellar systems, opening an essentially unexplored parameter space.

National Category
Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:su:diva-242964 (URN)10.3847/2041-8213/adaeb7 (DOI)2-s2.0-105002739455 (Scopus ID)
Available from: 2025-05-06 Created: 2025-05-06 Last updated: 2025-05-06Bibliographically approved
Rauer, H., Brandeker, A., Janson, M., Olofsson, G. & Dansac, L. M. (2025). The PLATO mission. Experimental astronomy, 59(3), Article ID 26.
Open this publication in new window or tab >>The PLATO mission
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2025 (English)In: Experimental astronomy, ISSN 0922-6435, E-ISSN 1572-9508, Vol. 59, no 3, article id 26Article in journal (Refereed) Published
Abstract [en]

PLATO (PLAnetary Transits and Oscillations of stars) is ESA’s M3 mission designed to detect and characterise extrasolar planets and perform asteroseismic monitoring of a large number of stars. PLATO will detect small planets (down to <2REarth) around bright stars (<11 mag), including terrestrial planets in the habitable zone of solar-like stars. With the complement of radial velocity observations from the ground, planets will be characterised for their radius, mass, and age with high accuracy (5%, 10%, 10% for an Earth-Sun combination respectively). PLATO will provide us with a large-scale catalogue of well-characterised small planets up to intermediate orbital periods, relevant for a meaningful comparison to planet formation theories and to better understand planet evolution. It will make possible comparative exoplanetology to place our Solar System planets in a broader context. In parallel, PLATO will study (host) stars using asteroseismology, allowing us to determine the stellar properties with high accuracy, substantially enhancing our knowledge of stellar structure and evolution. The payload instrument consists of 26 cameras with 12cm aperture each. For at least four years, the mission will perform high-precision photometric measurements. Here we review the science objectives, present PLATO‘s target samples and fields, provide an overview of expected core science performance as well as a description of the instrument and the mission profile towards the end of the serial production of the flight cameras. PLATO is scheduled for a launch date end 2026. This overview therefore provides a summary of the mission to the community in preparation of the upcoming operational phases.

Keywords
Asteroseismology, Exoplanets, PLATO mission
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:su:diva-242924 (URN)10.1007/s10686-025-09985-9 (DOI)2-s2.0-105003197453 (Scopus ID)
Available from: 2025-05-06 Created: 2025-05-06 Last updated: 2025-05-06Bibliographically approved
Chomez, A., Janson, M., Samland, M. & Wildi, F. (2025). The SPHERE infrared survey for exoplanets (SHINE) IV. Complete observations, data reduction and analysis, detection performances, and final results. Astronomy and Astrophysics, 697, Article ID A99.
Open this publication in new window or tab >>The SPHERE infrared survey for exoplanets (SHINE) IV. Complete observations, data reduction and analysis, detection performances, and final results
2025 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 697, article id A99Article in journal (Refereed) Published
Abstract [en]

Context. Over the past decade, large surveys with state-of-the-art planet-finder instruments such as Spectro-Polarimetric High-contrast Exoplanet REsearch on board Very Large Telescope (SPHERE@VLT), coupled with coronagraphic devices and extreme adaptive optics (AO) systems, have unveiled around 20 planetary mass companions at a semi-major axis greater than 10 astronomical units (au). Since direct imaging is the only detection technique with the ability to probe this outer region of planetary systems, the SPHERE infrared survey for exoplanets (SHINE) was designed and conducted from 2015 to 2021 to study the demographics of such young gas giant planets around 400 young nearby solar-type stars. The analysis of the first part of the survey focused on 150 stars (SHINE F150) was already published in a series of papers in 2021. An additional filler campaign called snapSHINE was conducted to acquire second epoch data, using shallow observations. Aims. In this paper, we present the observing strategy, data quality, and point source analysis of the full SHINE statistical sample as well as snapSHINE. Methods. Both surveys used the SPHERE@VLT instrument with the IRDIS dual band imager in conjunction with the integral field spectrograph (IFS) and the angular differential imaging observing technique. All SHINE data (650 datasets), corresponding to 400 stars, including the targets of the F150 survey, are processed in a uniform manner, with an advanced post-processing algorithm called PACO ASDI. An emphasis is put on the classification and identification of the most promising candidate companions. Results. Compared to the previous early analysis SHINE F150, the use of advanced post-processing techniques significantly improved the contrast detection limits by one or two magnitudes (x3-x6), which will allow us to put even tighter constraints on the radial distribution of young gas giants. This increased sensitivity directly sets SHINE apart as the largest and deepest direct imaging survey ever conducted. We detected and classified more than 3500 physical sources. One additional substellar companion was confirmed during the second phase of the survey (HIP 74865 B) and several new promising candidate companions are awaiting follow-up epoch confirmations.

Keywords
brown dwarfs, methods: observational, methods: statistical, planets and satellites: detection, techniques: high angular resolution, techniques: image processing
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:su:diva-243933 (URN)10.1051/0004-6361/202451751 (DOI)2-s2.0-105005265072 (Scopus ID)
Available from: 2025-06-10 Created: 2025-06-10 Last updated: 2025-06-10Bibliographically approved
El Morsy, M., Currie, T., Kuzuhara, M., Chilcote, J., Guyon, O., Tobin, T. L., . . . Vievard, S. (2024). Design, scientific goals, and performance of the SCExAO survey for planets around accelerating stars. In: Kathryn J. Jackson, Dirk Schmidt, Elise Vernet (Ed.), PROCEEDINGS VOLUME 13097, SPIE ASTRONOMICAL TELESCOPES + INSTRUMENTATION | 16-22 JUNE 2024: Adaptive Optics Systems IX. Paper presented at SPIE ASTRONOMICAL TELESCOPES + INSTRUMENTATION, Yokohama, Japan, June 16-22, 2024. SPIE, Article ID 130977I.
Open this publication in new window or tab >>Design, scientific goals, and performance of the SCExAO survey for planets around accelerating stars
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2024 (English)In: PROCEEDINGS VOLUME 13097, SPIE ASTRONOMICAL TELESCOPES + INSTRUMENTATION | 16-22 JUNE 2024: Adaptive Optics Systems IX / [ed] Kathryn J. Jackson, Dirk Schmidt, Elise Vernet, SPIE , 2024, article id 130977IConference paper, Published paper (Refereed)
Abstract [en]

We describe the motivation, design, and early results for our 42-night, 125 star Subaru/SCExAO direct imaging survey for planets around accelerating stars. Unlike prior large surveys, ours focuses only on stars showing evidence for an astrometric acceleration plausibly due to the dynamical pull of an unseen planet or brown dwarf. Our program is motivated by results from a recent pilot program that found the first planet jointly discovered from direct imaging and astrometry and resulted in a planet and brown dwarf discovery rate substantially higher than previous unbiased surveys like GPIES. The first preliminary results from our program reveal multiple new companions; discovered planets and brown dwarfs can be further characterized with follow-up data, including higher-resolution spectra. Finally, we describe the critical role this program plays in supporting the Roman Space Telescope Coronagraphic Instrument, providing a currently-missing list of targets suitable for the CGI technological demonstration without which the CGI tech demo risks failure.

Place, publisher, year, edition, pages
SPIE, 2024
Series
Proceedings of SPIE - The International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X ; 13097
Keywords
instrumentation: adaptive optics, instrumentation: spectrographs
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:su:diva-238930 (URN)10.1117/12.3019513 (DOI)001322664500181 ()2-s2.0-85206104166 (Scopus ID)
Conference
SPIE ASTRONOMICAL TELESCOPES + INSTRUMENTATION, Yokohama, Japan, June 16-22, 2024
Available from: 2025-02-06 Created: 2025-02-06 Last updated: 2025-02-06Bibliographically approved
Maire, A.-L., Janson, M. & Yazici, S. (2024). Direct imaging and dynamical mass of a benchmark T-type brown dwarf companion to HD 167665. Astronomy and Astrophysics, 691, Article ID A263.
Open this publication in new window or tab >>Direct imaging and dynamical mass of a benchmark T-type brown dwarf companion to HD 167665
2024 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 691, article id A263Article in journal (Refereed) Published
Abstract [en]

Context. A low-mass companion potentially in the brown dwarf mass regime was discovered on a ~12 yr orbit (~5.5 au) around HD 167665 using radial velocity (RV) monitoring. Joint RV–astrometry analyses confirmed that HD 167665B is a brown dwarf with precisions on the measured mass of ~4–9%. Brown dwarf companions with measured mass and luminosity are valuable for testing formation and evolutionary models. However, its atmospheric properties and luminosity are still unconstrained, preventing detailed tests of evolutionary models.

Aims. We further characterize the HD 167665 system by measuring the luminosity and refining the mass of its companion and reassessing the stellar age.

Methods. We present new high-contrast imaging data of the star and of its close-in environment from SPHERE and GRAVITY, which we combined with RV data from CORALIE and HIRES and astrometry from HIPPARCOS and Gaia.

Results. The analysis of the host star properties indicates an age of 6.20 ± 1.13 Gyr. GRAVITY reveals a point source near the position predicted from a joint fit of RV data and HIPPARCOS–Gaia proper motion anomalies. Subsequent SPHERE imaging confirms the detection and reveals a faint point source of contrast of ∆H2 = 10.95 ± 0.33 mag at a projected angular separation of ~180 mas. A joint fit of the high-contrast imaging, RV, and HIPPARCOS intermediate astrometric data together with the Gaia astrometric parameters constrains the mass of HD 167665B to ~1.2%, 60.3 ± 0.7 MJ. The SPHERE colors and spectrum point to an early or mid-T brown dwarf of spectral type . Fitting the SPHERE spectrophotometry and GRAVITY spectrum with synthetic spectra suggests an effective temperature of ~1000–1150 K, a surface gravity of ~5.0–5.4 dex, and a bolometric luminosity log(L/L)= dex. The mass, luminosity, and age of the companion can only be reproduced within 3σ by the hybrid cloudy evolutionary models of Saumon & Marley (2008, ApJ, 689, 1327), whereas cloudless evolutionary models underpredict its luminosity.

Keywords
Brown dwarfs, Methods: data analysis, Planets and satellites: dynamical evolution and stability, Stars: individual: HD 167665, Techniques: high angular resolution, Techniques: image processing
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:su:diva-240931 (URN)10.1051/0004-6361/202451184 (DOI)001376906300002 ()2-s2.0-85210484559 (Scopus ID)
Available from: 2025-03-21 Created: 2025-03-21 Last updated: 2025-03-21Bibliographically approved
Cesario, L., Janson, M. & Wordsworth, R. D. (2024). Large Interferometer For Exoplanets (LIFE): XIV. Finding terrestrial protoplanets in the galactic neighborhood. Astronomy and Astrophysics, 692, Article ID A172.
Open this publication in new window or tab >>Large Interferometer For Exoplanets (LIFE): XIV. Finding terrestrial protoplanets in the galactic neighborhood
2024 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 692, article id A172Article in journal (Refereed) Published
Abstract [en]

Context. The increased brightness temperature of young rocky protoplanets during their magma ocean epoch makes them potentially amenable to atmospheric characterization at distances from the Solar System far greater than thermally equilibrated terrestrial exoplanets, offering observational opportunities for unique insights into the origin of secondary atmospheres and the near surface conditions of prebiotic environments. Aims. The Large Interferometer For Exoplanets (LIFE) mission will employ a space-based midinfrared nulling interferometer to directly measure the thermal emission of terrestrial exoplanets. In this work, we seek to assess the capabilities of various instrumental design choices of the LIFE mission concept for the detection of cooling protoplanets with transient high-temperature magma ocean atmospheres at the tail end of planetary accretion. In particular, we investigate the minimum integration times necessary to detect transient magma ocean exoplanets in young stellar associations in the Solar neighborhood. Methods. Using the LIFE mission instrument simulator (LIFEsim), we assessed how specific instrumental parameters and design choices, such as wavelength coverage, aperture diameter, and photon throughput, facilitate or disadvantage the detection of protoplan-ets. We focused on the observational sensitivities of distance to the observed planetary system, protoplanet brightness temperature (using a blackbody assumption), and orbital distance of the potential protoplanets around both G- and M-dwarf stars. Results. Our simulations suggest that LIFE will be able to detect (S/N ≥ 7) hot protoplanets in young stellar associations up to distances of 100 pc from the Solar System for reasonable integration times (up to a few hours). Detection of an Earth-sized protoplanet orbiting a Solar-sized host star at 1 AU requires less than 30 minutes of integration time. M-dwarfs generally need shorter integration times. The contribution from wavelength regions smaller than 6 μm is important for decreasing the detection threshold and discriminating emission temperatures. Conclusions. The LIFE mission is capable of detecting cooling terrestrial protoplanets within minutes to hours in several local young stellar associations hosting potential targets. The anticipated compositional range of magma ocean atmospheres motivates further architectural design studies to characterize the crucial transition from primary to secondary atmospheres.

Keywords
Instrumentation: interferometers, Planets and satellites: detection, Planets and satellites: terrestrial planets
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:su:diva-240691 (URN)10.1051/0004-6361/202450764 (DOI)001376695600006 ()2-s2.0-85212458349 (Scopus ID)
Available from: 2025-03-14 Created: 2025-03-14 Last updated: 2025-03-14Bibliographically approved
Delorme, P., Chomez, A., Squicciarini, V., Janson, M., Flasseur, O., Schib, O., . . . Viswanath, G. (2024). Population of giant planets around B stars from the first part of the BEAST survey. Astronomy and Astrophysics, 692, Article ID A263.
Open this publication in new window or tab >>Population of giant planets around B stars from the first part of the BEAST survey
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2024 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 692, article id A263Article in journal (Refereed) Published
Abstract [en]

Context. Exoplanets form from circumstellar protoplanetary disks whose fundamental properties (notably their extent, composition, mass, temperature, and lifetime) depend on the host star properties, such as their mass and luminosity. B stars are among the most massive stars and their protoplanetary disks test extreme conditions for exoplanet formation.

Aims. This paper investigates the frequency of giant planet companions around young B stars (median age of 16 Myr) in the Scorpius-Centaurus (Sco-Cen) association, the closest association containing a large population of B stars.

Methods. We systematically searched for massive exoplanets with the high-contrast direct imaging instrument SPHERE using the data from the BEAST survey, which targets a homogeneous sample of young B stars from the wide Sco-Cen association. We derived accurate detection limits in the case of non-detections.

Results. We found evidence in previous papers for two substellar companions around 42 stars. The masses of these companions are straddling the ~13 Jupiter mass deuterium burning limit, but their mass ratio with respect to their host star is close to that of Jupiter. We derived a frequency of such massive planetary-mass companions around B stars of , accounting for the survey sensitivity.

Conclusions. The discoveries of substellar companions b Centaurib and μ2 Sco B happened after only a few stars in the survey had been observed, raising the possibility that massive Jovian planets might be common around B stars. However, our statistical analysis shows that the occurrence rate of such planets is similar around B stars and around solar-type stars of a similar age, while B-star companions exhibit low mass ratios and a larger semi-major axis.

Keywords
Methods: statistical, Planets and satellites: detection, Planets and satellites: formation, Planets and satellites: gaseous planets, Stars: massive
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:su:diva-240681 (URN)10.1051/0004-6361/202451461 (DOI)001380988400005 ()2-s2.0-85212786668 (Scopus ID)
Available from: 2025-03-12 Created: 2025-03-12 Last updated: 2025-03-12Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-8345-593x

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