A5065888103- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Space Exploration and Technology
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
Stockholm University
2021-2024
AlbaNova
2021-2024
Context. Accretion at planetary-mass companions (PMCs) suggests the presence of a protoplanetary disc in system, likely accompanied by circumplanetary disc. High-resolution spectroscopy accreting PMCs is very difficult due to their proximity bright host stars. For well-separated companions, however, such spectra are feasible and they unique windows into accretion. Aims. We have followed up on our observations 40-Myr, still accreting, circumbinary PMC Delorme 1 (AB)b. used high-resolution...
Context. Accreting planetary-mass objects have been detected at H α , but targeted searches mainly resulted in non-detections. Accretion tracers the regime could originate from shock itself, making them particularly susceptible to extinction by accreting material. High-resolution ( R > 50 000) spectrographs operating should soon enable one study how incoming material shapes line profile. Aims. We calculate much gas and dust onto a planet reduce flux planetary surface they affect shape....
Virtually all known exoplanets reside around stars with $M<2.3~M_\odot$; to clarify if the dearth of planets more massive is real, we launched direct-imaging B-star Exoplanet Abundance STudy (BEAST) survey targeting B ($M>2.4~M_\odot$) in young (5-20 Myr) Scorpius-Centaurus association (Sco-Cen). Here present case a ($M \sim 9~M_\odot$) BEAST target, $\mu^2$ Sco. Based on kinematic information, found that Sco member small group which label Eastern Lower Scorpius, refining turn precision...
Forbidden emission lines in protoplanetary disks are a key diagnostic studies of the evolution disk and host star. We report spatially resolved lines, [OI] 6300, 6363, [NII] 6548, 6583, H$\alpha$, [SII] 6716, 6730 Angstrom that believed to be associated with jets magnetically driven winds inner disks. Observations were carried out optical integral field spectrograph Multi Unit Spectroscopic Explorer (MUSE), at Very Large Telescope (VLT). With resolution 0.025 X arcsec$^{2}$, we aim derive...
Context . Accretion among planetary mass companions is a poorly understood phenomenon, due to the lack of both observational and theoretical studies. The detection emission lines from accreting gas giants facilitates detailed investigations into this process. Aims This work presents analysis Balmer one few known young, planetary-mass objects with observed emission, isolated L2 γ dwarf 2MASS J11151597+1937266 between 7 21 M Jup an age 5–45 Myr, located at 45 ± 2 pc. Methods We obtained first...
Recent observations from B-star Exoplanet Abundance Study (BEAST) have illustrated the existence of sub-stellar companions around very massive stars. In this paper, we present detection two lower mass to a relatively nearby ($148.7^{+1.5}_{-1.3}$ pc), young ($17^{+3}_{-4}$ Myr), bright (V=$6.632\pm0.006$ mag), $2.58\pm0.06~ M_{\odot}$ B9V star HIP 81208 residing in Sco-Cen association, using Spectro-Polarimetric High-contrast REsearch (SPHERE) instrument at Very Large Telescope (VLT) Chile....
Active comets have been detected in several exoplanetary systems, although so far only indirectly, when the dust or gas extended coma has transited front of stellar disk. The large optical surface and relatively high temperature an active cometary also makes it suitable to study with direct imaging, but angular separation is generally too small be reachable present-day facilities. However, future imaging facilities ability detect terrestrial planets habitable zones nearby systems will...
Context. Since 2019, the direct imaging B-star Exoplanet Abundance STudy (BEAST) at SPHERE@VLT has been scanning surroundings of young B-type stars in order to ascertain ultimate frontiers giant planet formation. Recently, 17 −4 +3 Myr HIP 81208 was found host a close-in (∼50 au) brown dwarf and wider (∼230 late M star around central 2.6 ⊙ primary. Aims. Alongside continuation survey, we are undertaking complete reanalysis archival data aimed improving detection performances so as uncover...
Accretion among planets is a poorly understood phenomenon, due to lack of both observational and theoretical studies. Detection emission lines from accreting gas giants facilitate detailed investigations into this process. This work presents analysis Balmer one the few known young, planetary-mass objects with observed emission, isolated L2 dwarf 2MASS J11151597+1937266 mass 7-21 Mj age 5-45 Myr, located at 45+-2 pc. We obtained first high-resolution (R~50,000) spectrum target VLT/UVES,...
Exoplanets form from circumstellar protoplanetary discs whose fundamental properties (notably their extent, composition, mass, temperature and lifetime) depend on the host star properties, such as mass luminosity. B-stars are among most massive stars test extreme conditions for exoplanet formation. This paper investigates frequency of giant planet companions around young (median age 16 Myr) in Scorpius-Centaurus association, closest association containing a large population B-stars. We...
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 mass luminosity. B stars are among most massive test extreme conditions for exoplanet formation. This paper investigates frequency of giant planet companions around young (median age 16 Myr) in Scorpius-Centaurus (Sco-Cen) association, closest association containing a large population stars. We...
Recent observations from B-star Exoplanet Abundance Study (BEAST) have illustrated the existence of sub-stellar companions around very massive stars. In this paper, we present detection two lower mass to a relatively nearby ($148.7^{+1.5}_{-1.3}$ pc), young ($17^{+3}_{-4}$ Myr), bright (V=$6.632\pm0.006$ mag), $2.58\pm0.06~ M_{\odot}$ B9V star HIP 81208 residing in Sco-Cen association, using Spectro-Polarimetric High-contrast REsearch (SPHERE) instrument at Very Large Telescope (VLT) Chile....
Active comets have been detected in several exoplanetary systems, although so far only indirectly, when the dust or gas extended coma has transited front of stellar disk. The large optical surface and relatively high temperature an active cometary also makes it suitable to study with direct imaging, but angular separation is generally too small be reachable present-day facilities. However, future imaging facilities ability detect terrestrial planets habitable zones nearby systems will...
Since 2019, the direct imaging B-star Exoplanet Abundance Study (BEAST) at SPHERE@VLT has been scanning surroundings of young B-type stars in order to ascertain ultimate frontiers giant planet formation. Recently, $17^{+3}_{-4}$ Myr HIP 81208 was found host a close-in (~50 au) brown dwarf and wider (~230 late M star around central 2.6Msun primary. Alongside continuation survey, we are undertaking complete reanalysis archival data aimed improving detection performances so as uncover...
We have followed up on our observations of the ~ 40-Myr, and still accreting, PMC Delorme 1 (AB)b. used high-resolution spectroscopy to characterise accretion process further by accessing wealth emission lines in near-UV. With VLT/UVES, we obtained R 50000 at 330--452 nm. After separating companion from that M5 low-mass binary, performed a detailed emission-line analysis, which included planetary shock modelling. reaffirm ongoing (AB)b report first detections (super-Jovian) protoplanet...
Accreting planets have been seen at Ha (H alpha), but targeted searches not fruitful. For planets, accretion tracers should come from the shock itself, exposing them to extinction by accreting material. High-resolution (R>5e4) spectrographs soon allow studying how incoming material shapes line profile. We calculate much gas and dust onto a planet reduce flux planetary surface they affect shapes. also study absorption-modified relationship between luminosity Mdot. compute high-resolution...
Planet formation occurs around a wide range of stellar masses and system architectures. An improved understanding the process can be achieved by studying it across full parameter space, particularly toward extremes. Earlier studies planets in close-in orbits high-mass stars have revealed an increase giant planet frequency with increasing mass until turnover point at 1.9 solar masses, above which rapidly decreases. This could potentially imply that is impeded more massive stars, exceeding 3...