A5031925888- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Galaxies: Formation, Evolution, Phenomena
- Adaptive optics and wavefront sensing
- Astro and Planetary Science
- Cosmology and Gravitation Theories
- History and Developments in Astronomy
- Astrophysical Phenomena and Observations
- Geophysics and Gravity Measurements
- Pulsars and Gravitational Waves Research
- Calibration and Measurement Techniques
- Molecular Spectroscopy and Structure
- Scientific Measurement and Uncertainty Evaluation
- Bee Products Chemical Analysis
- Optical Polarization and Ellipsometry
- Solar Thermal and Photovoltaic Systems
- Solar and Space Plasma Dynamics
- Scientific Research and Discoveries
- Medical Imaging Techniques and Applications
- Atomic and Subatomic Physics Research
- Computer Graphics and Visualization Techniques
- Relativity and Gravitational Theory
University of Liège
2012-2022
University of Bonn
2017-2019
NASA Exoplanet Science Institute
2015
California Institute of Technology
2015
Ames Research Center
2015
Chinese Academy of Sciences
2013
We present the Vortex Image Processing (VIP) library, a python package dedicated to astronomical high-contrast imaging. Our relies on extensive stack of scientific libraries and aims provide flexible framework for data image processing. In this paper, we describe capabilities VIP related processing sequences acquired using angular differential imaging (ADI) observing technique. implements functionalities building pipelines, encompass- ing pre- post-processing algorithms, potential sources...
Abstract We report the first unambiguous detection and mass measurement of an isolated stellar-mass black hole (BH). used Hubble Space Telescope (HST) to carry out precise astrometry source star long-duration ( t E ≃ 270 days), high-magnification microlensing event MOA-2011-BLG-191/OGLE-2011-BLG-0462 (hereafter designated as MOA-11-191/OGLE-11-462), in direction Galactic bulge. HST imaging, conducted at eight epochs over interval 6 yr, reveals a clear relativistic astrometric deflection...
We present new ground-based, multi-colour, broad-band photometric measurements of the physical parameters, transmission and emission spectra transiting extrasolar planet WASP-19b. The are based on observations eight transits four occultations through a Gunn i filter using 1.54-m Danish Telescope, 14 an Rc at Perth Exoplanet Survey Telescope (PEST) observatory one transit observed simultaneously optical (Sloan g′, r′, i′, z′) three near-infrared (J, H, K) filters, Gamma Ray Burst Optical...
We report the detection of a Cold Neptune m_planet=21+/-2MEarth orbiting 0.38MSol M dwarf lying 2.5-3.3 kpc toward Galactic center as part campaign combining ground-based and Spitzer observations to measure distribution planets. This is first time that complex real-time protocols described by Yee et al. (2015), which aim maximize planet sensitivity while maintaining sample integrity, have been carried out in practice. Multiple survey follow-up teams successfully combined their efforts within...
We present time-series photometric observations of thirteen transits in the planetary systems WASP-24, WASP-25 and WASP-26. All three have orbital obliquity measurements, WASP-24 WASP-26 been observed with Spitzer, was previously comparatively neglected. Our light curves were obtained using telescope-defocussing method scatters 0.5 to 1.2 mmag relative their best-fitting geometric models. used these data measure physical properties ephemerides high precision, finding that our improved...
ABSTRACT An optical vortex coronagraph has been implemented within the NIRC2 camera on Keck II telescope and used to carry out on-sky tests observations. The development of this new L ′-band observational mode is described, an initial demonstration capability presented: a resolved image low-mass companion HIP 79124, which had previously detected by means interferometry. With 79124 B at projected separation 186.5 mas, both small inner working angle related imaging improvements were crucial in...
Aims: We present 11 high-precision photometric transit observations of the transiting super-Earth planet GJ1214b. Combining these data with from other authors, we investigate ephemeris for possible signs timing variations (TTVs) using a Bayesian approach. Methods: The were obtained telescope-defocusing techniques, and achieve high precision random errors in photometry as low 1mmag per point. To possibility TTVs light curve, calculate overall probability TTV signal methods. Results: are used...
We report 13 high-precision light curves of eight transits the exoplanet WASP-52b, obtained by using four medium-class telescopes, through different filters, and adopting defocussing technique. One transit was recorded simultaneously from two observatories another one same site but with instruments, including a multi-band camera. Anomalies were clearly detected in five modelled as starspots occulted planet during events. fitted clean jktebop code, those anomalies prism+gemc codes order to...
We present photometric observations of four transits in the WASP-17 planetary system, obtained using telescope defocusing techniques and with scatters reaching 0.5 mmag per point. Our revised orbital period is 4.0 ± 0.6 s longer than previous measurements, a difference 6.6σ, does not support published detections eccentricity this system. model light curves jktebop code calculate physical properties system by recourse to five sets theoretical stellar predictions. The resulting radius, Rb =...
We present microlens parallax measurements for 21 (apparently) isolated lenses observed toward the Galactic bulge that were imaged simultaneously from Earth and Spitzer, which was ∼1 AU west of in projection. combine these with a kinematic model Galaxy to derive distance estimates each lens, error bars are small compared Sun's galactocentric distance. The ensemble therefore yields well-defined cumulative distribution lens distances. In principle, it is possible compare this against set...
WASP-80 is one of only two systems known to contain a hot Jupiter which transits its M-dwarf host star. We present eight light curves transit event, obtained simultaneously using defocussed telescopes. These data were taken through the Bessell I, Sloan griz and near-infrared JHK passbands. use our search for opacity-induced changes in planetary radius, but find that all values agree with each other. Our are therefore consistent flat transmission spectrum within observational uncertainties....
We present 17 transit light curves of the ultrashort period planetary system WASP-103, a strong candidate for detection tidally-induced orbital decay. use these to establish high-precision reference epoch timing studies. The time mid-point is now measured an accuracy 4.8 s, versus 67.4 s in discovery paper, aiding future searches With help published spectroscopic measurements and theoretical stellar models, we determine physical properties high precision detailed error budget calculations....
HR8799 is orbited by at least four giant planets, making it a prime target for the recently commissioned Spectro-Polarimetric High-contrast Exoplanet REsearch (VLT/SPHERE). As such, was observed on five consecutive nights during SPHERE science verification in December 2014. We aim to take full advantage of capabilities derive accurate astrometric measurements based H-band images acquired with Infra-Red Dual-band Imaging and Spectroscopy (IRDIS) subsystem, explore ultimate performance this...
Transition disks offer the extraordinary opportunity to look for newly born planets and investigate early stages of planet formation. In this context we observed Herbig A5 star MWC 758 with L band vector vortex coronagraph installed in near-infrared camera spectrograph NIRC2 at Keck II telescope, aim unveiling nature spiral structure by constraining presence planetary companions system. Our high-contrast imaging observations show a bright (delta L=7.0+/-0.3 mag) point-like emission, south...
The extrasolar planet WASP-67 b is the first hot Jupiter definitively known to undergo only partial eclipses. lack of second and third contact point in this planetary system makes it difficult obtain accurate measurements its physical parameters. Aims. By using new high-precision photometric data, we confirm that shows grazing eclipses compute estimates properties parent star. Methods. We present high-quality, multi-colour, broad-band observations comprising five light curves covering two...
(abridged) Context. Wide binaries are a potential pathway for the formation of hot Jupiters. The binary fraction among host stars is an important discriminator between competing theories, but has not been well characterised. Additionally, contaminating light from unresolved can significantly affect accuracy photometric and spectroscopic measurements in studies transiting exoplanets. Aims. We observed 101 exoplanet systems Southern hemisphere order to create homogeneous catalogue both bound...
We present new photometric observations of WASP-15 and WASP-16, two transiting extrasolar planetary systems with measured orbital obliquities but without follow-up since their discovery papers. Our data for comprise one transit simultaneously in four optical passbands using GROND on the MPG/European Southern Observatory (ESO) 2.2 m telescope, plus coverage half a from DFOSC Danish 1.54 both at ESO La Silla. For WASP-16 we complete transits, all telescope. use these to refine physical...
We present 13 high-precision and four additional light curves of bright southern-hemisphere transiting planetary systems: WASP-22, WASP-41, WASP-42 WASP-55. In the cases WASP-55, these are first follow-up observations since their discovery papers. refined measurements physical properties orbital ephemerides all systems. No indications transit timing variations were seen. All planets have radii inflated above those expected from theoretical models gas-giant planets; WASP-55b is most...
Aims: In this work, we aim to provide a reliable list of gravitational lens (GL) candidates based on search performed over the entire Gaia Data Release 2 (Gaia DR2). We also show that sole astrometric and photometric informations coming from satellite yield sufficient insights for supervised learning methods automatically identify GL with an efficiency is comparable image processing. Methods: simulated 106,623,188 systems composed more than two images, regular grid parameters characterizing...
Accurate measurements of the physical characteristics a large number exoplanets are useful to strongly constrain theoretical models planet formation and evolution, which lead variety planetary-system configurations that have been observed. We present study planetary systems WASP-45 WASP-46, both composed main-sequence star close-in hot Jupiter, based on 29 new high-quality light curves transits events. In particular, one transit b four WASP-46 were simultaneously observed in optical filters,...
We report on the mass and distance measurements of two single-lens events from 2015 \emph{Spitzer} microlensing campaign. With both finite-source effect microlens parallax measurements, we find that lens OGLE-2015-BLG-1268 is very likely a brown dwarf. Assuming source star lies behind same amount dust as Bulge red clump, $45\pm7$ $M_{\rm J}$ dwarf at $5.9\pm1.0$ kpc. The second event, OGLE-2015-BLG-0763, $0.50\pm0.04$ $M_\odot$ $6.9\pm1.0$ show probability to definitively measure isolated...
HD 141569 A is a pre-main sequence B9.5 Ve star surrounded by prominent and complex circumstellar disk, likely still in transition stage from protoplanetary to debris disk phase. Here, we present new image of the third inner component made L' band (3.8 micron) during commissioning vector vortex coronagraph recently installed near-infrared imager spectrograph NIRC2 behind W.M. Keck Observatory II adaptive optics system. We used reference point spread function subtraction, which reveals...