M. Janson
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View article: SCExAO/CHARIS and Gaia Direct Imaging and Astrometric Discovery of a Superjovian Planet 3–4 <i>λ</i> / <i>D</i> from the Accelerating Star HIP 54515*
SCExAO/CHARIS and Gaia Direct Imaging and Astrometric Discovery of a Superjovian Planet 3–4 <i>λ</i> / <i>D</i> from the Accelerating Star HIP 54515* Open
We present the discovery of a superjovian planet around the young A5 star HIP 54515, detected using precision astrometry from the Hipparcos Gaia Catalogue of Accelerations and high-contrast imaging with SCExAO/CHARIS from the recently comm…
View article: OASIS Survey Direct Imaging and Astrometric Discovery of HIP 71618 B: A Substellar Companion Suitable for the Roman Coronagraph Technology Demonstration*
OASIS Survey Direct Imaging and Astrometric Discovery of HIP 71618 B: A Substellar Companion Suitable for the Roman Coronagraph Technology Demonstration* Open
We present the OASIS survey program discovery of a substellar companion orbiting the young A1V star HIP 71618, detected using precision astrometry from Gaia and Hipparcos and high-contrast imaging with SCExAO/CHARIS and Keck/NIRC2. Atmosph…
View article: The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems. VI. Evidence for Radially Evolving Icy Grains in the HD 141569A Disk via NIRCam Coronagraphic Imaging
The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems. VI. Evidence for Radially Evolving Icy Grains in the HD 141569A Disk via NIRCam Coronagraphic Imaging Open
We present JWST NIRCam coronagraphic observations of the HD 141569A circumstellar disk, obtained as part of the JWST Early Release Science program. The observations recover the multi-ringed structure seen in previous shorter-wavelength obs…
View article: ExoplaNeT accRetion mOnitoring sPectroscopic surveY (ENTROPY) - II. Time series of Balmer line profiles of Delorme 1(AB)b
ExoplaNeT accRetion mOnitoring sPectroscopic surveY (ENTROPY) - II. Time series of Balmer line profiles of Delorme 1(AB)b Open
Accretion processes in the planetary-mass regime remain poorly constrained, yet they strongly influence planet formation, evolution, and the composition of circumplanetary disks (CPDs). We investigate the resolved Balmer hydrogen emission-…
View article: Direct Imaging Explorations for Companions from the Subaru/IRD Strategic Program II; Discovery of a Brown-dwarf Companion around a Nearby mid-M~dwarf LSPM~J1446+4633
Direct Imaging Explorations for Companions from the Subaru/IRD Strategic Program II; Discovery of a Brown-dwarf Companion around a Nearby mid-M~dwarf LSPM~J1446+4633 Open
We report the discovery of a new directly-imaged brown dwarf companion with Keck/NIRC2+pyWFS around a nearby mid-type M~dwarf LSPM~J1446+4633 (hereafter J1446). The $L'$-band contrast ($4.5\times10^{-3}$) is consistent with a $\sim20-60\ M…
View article: YSES 2b is a background star
YSES 2b is a background star Open
Aims . We wish to confirm the nature of YSES 2b, a purportedly faint companion of the young star YSES 2. Methods . We used on-sky observations from SPHERE and GRAVITY to measure the astrometric position of 2b with respect to the star YSES …
View article: 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 <i>μ</i>m
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 <i>μ</i>m Open
We present aperture masking interferometry (AMI) observations of the star HIP 65426 at 3.8 μ m, as part of the JWST Direct Imaging Early Release Science program, obtained using the Near Infrared Imager and Slitless Spectrograph instrument.…
View article: The SPHERE infrared survey for exoplanets (SHINE)
The SPHERE infrared survey for exoplanets (SHINE) Open
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 e…
View article: Characterization of AF Lep b at high spectral resolution with VLT/HiRISE
Characterization of AF Lep b at high spectral resolution with VLT/HiRISE Open
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 3.6…
View article: On the Orbit of the Binary Brown Dwarf Companion GL229 Ba and Bb
On the Orbit of the Binary Brown Dwarf Companion GL229 Ba and Bb Open
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 m…
View article: Characterization of AF Lep b at high spectral resolution with VLT/HiRISE
Characterization of AF Lep b at high spectral resolution with VLT/HiRISE Open
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 \pm 0.…
View article: On the Orbit of the Binary Brown Dwarf Companion GL229 Ba and Bb
On the Orbit of the Binary Brown Dwarf Companion GL229 Ba and Bb Open
The companion GL229B was recently resolved by Xuan et al. (2024) as a tight binary of two brown dwarfs (Ba and Bb) through VLTI-GRAVITY interferometry and VLT-CRIRES+ RV measurements. Here, we present Bayesian models of the interferometric…
View article: The SPHERE infrared survey for exoplanets (SHINE). V. Complete observations, data reduction and analysis, detection performances, and final results
The SPHERE infrared survey for exoplanets (SHINE). V. Complete observations, data reduction and analysis, detection performances, and final results Open
During the past decade, state-of-the-art planet-finder instruments like SPHERE@VLT, coupling coronagraphic devices and extreme adaptive optics systems, unveiled, thanks to large surveys, around 20 planetary mass companions at semi-major ax…
View article: Deep high-resolution L band spectroscopy in the $β$ Pictoris planetary system
Deep high-resolution L band spectroscopy in the $β$ Pictoris planetary system Open
The beta Pictoris system, with its two directly imaged planets beta Pic b and beta Pic c and its well characterised debris disk, is a prime target for detailed characterisation of young planetary systems. Here, we present high-resolution a…
View article: Deep high-resolution L band spectroscopy in the <i>β</i> Pictoris planetary system
Deep high-resolution L band spectroscopy in the <i>β</i> Pictoris planetary system Open
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-c…
View article: The Impact of Water Clouds on the Prospective Emission Spectrum of Teegarden’s Star b as Observed by LIFE
The Impact of Water Clouds on the Prospective Emission Spectrum of Teegarden’s Star b as Observed by LIFE Open
Nontransiting terrestrial planets will be accessible by upcoming observatories of which LIFE is an example. Planet b orbiting Teegarden’s Star is one of the optimal targets for such missions. We use a one-dimensional atmospheric model with…
View article: The impact of water clouds on the prospective emission spectrum of Teegarden's Star b as observed by LIFE
The impact of water clouds on the prospective emission spectrum of Teegarden's Star b as observed by LIFE Open
Non-transiting terrestrial planets will be accessible by upcoming observatories of which LIFE is an example. Planet b orbiting Teegarden's Star is one of the optimal targets for such missions. We use a one-dimensional atmospheric model wit…
View article: Large Interferometer For Exoplanets (LIFE)
Large Interferometer For Exoplanets (LIFE) Open
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 equilib…
View article: Large Interferometer For Exoplanets (LIFE). XIV. Finding terrestrial protoplanets in the galactic neighborhood
Large Interferometer For Exoplanets (LIFE). XIV. Finding terrestrial protoplanets in the galactic neighborhood Open
The increased brightness temperature of young rocky protoplanets during their magma ocean epoch makes them potentially amenable to atmospheric characterization to distances from the solar system far greater than thermally equilibrated terr…
View article: ExoplaNeT accRetion mOnitoring sPectroscopic surveY (ENTROPY)
ExoplaNeT accRetion mOnitoring sPectroscopic surveY (ENTROPY) Open
Context . Accretion among planetary mass companions is a poorly understood phenomenon, due to the lack of both observational and theoretical studies. The detection of emission lines from accreting gas giants facilitates detailed investigat…
View article: Direct imaging and dynamical mass of a benchmark T-type brown dwarf companion to HD 167665
Direct imaging and dynamical mass of a benchmark T-type brown dwarf companion to HD 167665 Open
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 …
View article: Exoplanet accretion monitoring spectroscopic survey (ENTROPY) I. Evidence for magnetospheric accretion in the young isolated planetary-mass object 2MASS J11151597+1937266
Exoplanet accretion monitoring spectroscopic survey (ENTROPY) I. Evidence for magnetospheric accretion in the young isolated planetary-mass object 2MASS J11151597+1937266 Open
Accretion among planets is a poorly understood phenomenon, due to lack of both observational and theoretical studies. Detection of emission lines from accreting gas giants facilitate detailed investigations into this process. This work pre…
View article: Design, scientific goals, and performance of the SCExAO survey for planets around accelerating stars
Design, scientific goals, and performance of the SCExAO survey for planets around accelerating stars Open
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 astr…
View article: The MIRI Exoplanets Orbiting White dwarfs (MEOW) Survey: Mid-infrared Excess Reveals a Giant Planet Candidate around a Nearby White Dwarf
The MIRI Exoplanets Orbiting White dwarfs (MEOW) Survey: Mid-infrared Excess Reveals a Giant Planet Candidate around a Nearby White Dwarf Open
The MIRI Exoplanets Orbiting White dwarfs survey is a cycle 2 JWST program to search for exoplanets around dozens of nearby white dwarfs via infrared excess and direct imaging. In this Letter, we present the detection of mid-infrared exces…
View article: The MIRI Exoplanets Orbiting White Dwarfs (MEOW) Survey: Mid-Infrared Excess Reveals a Giant Planet Candidate around a Nearby White Dwarf
The MIRI Exoplanets Orbiting White Dwarfs (MEOW) Survey: Mid-Infrared Excess Reveals a Giant Planet Candidate around a Nearby White Dwarf Open
The MIRI Exoplanets Orbiting White dwarfs (MEOW) Survey is a cycle 2 JWST program to search for exoplanets around dozens of nearby white dwarfs via infrared excess and direct imaging. In this paper, we present the detection of mid-infrared…
View article: The Large Interferometer For Exoplanets (LIFE): a space mission for mid-infrared nulling interferometry
The Large Interferometer For Exoplanets (LIFE): a space mission for mid-infrared nulling interferometry Open
Glauser, Adrian M. et al.-- Full list of authors: Glauser, Adrian M.; Quanz, Sascha P.; Hansen, Jonah; Dannert, Felix; Ireland, Michael; Linz, Hendrik; Absil, Olivier; Alei, Eleonora; Angerhausen, Daniel; Birbacher, Thomas; Defrère, Denis;…
View article: Gliese 12 b: A Temperate Earth-sized Planet at 12 pc Ideal for Atmospheric Transmission Spectroscopy
Gliese 12 b: A Temperate Earth-sized Planet at 12 pc Ideal for Atmospheric Transmission Spectroscopy Open
Recent discoveries of Earth-sized planets transiting nearby M dwarfs have made it possible to characterize the atmospheres of terrestrial planets via follow-up spectroscopic observations. However, the number of such planets receiving low i…
View article: The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems. V. Do Self-consistent Atmospheric Models Represent JWST Spectra? A Showcase with VHS 1256–1257 b
The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems. V. Do Self-consistent Atmospheric Models Represent JWST Spectra? A Showcase with VHS 1256–1257 b Open
The unprecedented medium-resolution ( R λ ∼ 1500–3500) near- and mid-infrared (1–18 μ m) spectrum provided by JWST for the young (140 ± 20 Myr) low-mass (12–20 M Jup ) L–T transition (L7) companion VHS 1256 b gives access to a catalog of m…
View article: The SPHERE view of the Taurus star-forming region
The SPHERE view of the Taurus star-forming region Open
The sample of planet-forming disks observed by high-contrast imaging campaigns over the last decade is mature enough to enable the demographical analysis of individual star-forming regions. We present the full census of Taurus sources with…