G. J. J. Talens
A5004908822- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Gamma-ray bursts and supernovae
- Calibration and Measurement Techniques
- Geochemistry and Geologic Mapping
- Spectroscopy Techniques in Biomedical and Chemical Research
- Spectroscopy and Laser Applications
- Infrared Target Detection Methodologies
- Solar and Space Plasma Dynamics
- Astrophysical Phenomena and Observations
- Technology Assessment and Management
- Astrophysics and Cosmic Phenomena
- Mechanics and Biomechanics Studies
- Spectroscopy and Chemometric Analyses
- Galaxies: Formation, Evolution, Phenomena
- Enzyme Production and Characterization
Université de Montréal
2019-2024
Princeton University
2022-2023
Leiden University
2016-2019
Leiden Observatory
2016-2019
We have used the HARPS-North high resolution spectrograph ($\mathcal{R}$=115 000) at TNG to observe one transit of highly irradiated planet MASCARA-2b/KELT-20b. Using only observation, we are able clearly resolve spectral features atomic sodium (Na I) doublet and H$\alpha$ line in its atmosphere, measuring absorption depths 0.17$\pm$0.03$\%$ 0.59$\pm$0.08$\%$ for a 0.75 $\AA$ passband, respectively. These absorptions corroborated with transmission measured from their respective light curves,...
Abstract The Near-Infrared Imager and Slitless Spectrograph (NIRISS) is the science module of Canadian-built Fine Guidance Sensor onboard James Webb Space Telescope (JWST). NIRISS has four observing modes: (1) broadband imaging featuring seven eight NIRCam filters, (2) wide-field slitless spectroscopy at a resolving power ∼150 between 0.8 2.2 μ m, (3) single-object cross-dispersed (SOSS) enabling simultaneous wavelength coverage 0.6 2.8 m R ∼ 700, mode optimized for exoplanet relatively...
The future is now - after its long-awaited launch in December 2021, JWST began science operations July 2022 and already revolutionizing exoplanet astronomy. Early Release Observations (ERO) program was designed to provide the first images spectra from JWST, covering a multitude of cases using multiple modes each on-board instrument. Here, we present transmission spectroscopy observations hot-Saturn WASP-96b with Single Object Slitless Spectroscopy (SOSS) mode Near Infrared Imager...
The Near Infrared Imager and Slitless Spectrograph instrument (NIRISS) is the Canadian Space Agency (CSA) contribution to suite of four science instruments JWST. As one three NIRISS observing modes, Single Object Spectroscopy (SOSS) mode tailor-made undertake time-series observations exoplanets perform transit spectroscopy. SOSS permits point sources between 0.6 2.8 um at a resolving power 650 1.25 using slit-less cross-dispersing grism while its defocussing cylindrical lens enables targets...
We investigate the connection between morphology and internal kinematics of stellar component central galaxies with mass |$M_\star \gt {10}^{9.5} \, {\rm M}_\odot$| in EAGLE simulations. compare several kinematic diagnostics commonly used to describe simulated galaxies, find good consistency them. model structure as ellipsoids quantify their via ratios principal axes. show that differentiation blue star-forming red quiescent using morphological can be achieved similar efficacy use...
In this paper we present MASCARA-2 b, a hot Jupiter transiting the $m_V=7.6$ A2 star HD 185603. Since early 2015, MASCARA has taken more than 1.6 million flux measurements of star, corresponding to total almost 3000 hours observations, revealing periodic dimming in with depth $1.3\%$. Photometric follow-up observations were performed NITES and IAC80 telescopes spectroscopic obtained Hertzsprung SONG telescope. We find b orbits 185603 period $3.474119^{+0.000005}_{-0.000006}~\rm{days}$ at...
This paper describes the design, operations, and performance of Multi-site All-Sky CAmeRA (MASCARA). Its primary goal is to find new exoplanets transiting bright stars, 4 < mV 8, by monitoring full sky. MASCARA consists one northern station on La Palma, Canary Islands (fully operational since February 2015), southern at Silla Observatory, Chile (operational from early 2017), a data centre Leiden Observatory in Netherlands. Both stations are equipped with five interline CCD cameras using wide...
Abstract After a successful launch, the James Webb Space Telescope is preparing to undertake one of its principal mission objectives, characterization atmospheres exoplanets. The Single Object Slitless Spectroscopy (SOSS) mode Near Infrared Imager and Spectrograph (NIRISS) only observing that has been specifically designed for this objective. It features wide simultaneous spectral range (0.6–2.8 μ m) through two diffraction orders. However, due mechanical constraints, these orders overlap...
We report the discovery of MASCARA-1 b, first exoplanet discovered with Multi-site All-Sky CAmeRA (MASCARA). It is a hot Jupiter orbiting bright $m_V=8.3$, rapidly rotating ($v\sin i_\star > 100~\rm{km~s}^{-1}$) A8 star period $2.148780\pm8\times10^{-6} ~\rm{days}$. The planet has mass and radius $3.7\pm0.9~\rm{M}_{\rm{Jup}}$ $1.5\pm0.3~\rm{R}_{\rm{Jup}}$, respectively. As most Jupiters transiting early-type stars we find misalignment between orbital axis stellar spin axis, which may be...
The SOSS mode of the NIRISS instrument is poised to be one workhorse modes for exoplanet atmosphere observations with newly launched James Webb Space Telescope. One challenges mode, however, physical overlap first two diffraction orders G700XD grism on detector. Recently, ATOCA algorithm was developed and implemented as an option in official JWST pipeline, a method extract spectra by decontaminating detector -- that is, separating second orders. Here, we present APPLESOSS (A Producer...
Abstract MASCARA-4 b is a hot Jupiter in highly misaligned orbit around rapidly rotating A3V star that was observed for 54 days by the Transiting Exoplanet Survey Satellite ( TESS ). We perform two analyses of using stellar gravity-darkened model. First, we measure b’s orbital configuration modeling its photometric light curve. take advantage asymmetry transit due to host star’s surface true spin–orbit angle be 104° <?CDATA ${}_{-{13}^{^\circ }}^{+{7}^{^\circ }}$?> . also detect ∼4 σ...
Exoplanet properties crucially depend on their host stars' parameters. In case the exoplanet star shows pulsations, asteroseismology can be used for an improved description of stellar We aim to revisit pulsational beta Pic and identify its pulsation modes from normalised amplitudes in five different passbands. also investigate potential presence a magnetic field. conduct frequency analysis using three seasons BRITE-Constellation observations BRITE blue red filters, ~620-day long bRing light...
Context . The Multi-site All-Sky CAmeRA (MASCARA) aims to find the brightest transiting planet systems by monitoring full sky at magnitudes 4 < V 8.4, taking data every 6.4 s. northern station has been operational on La Palma since February 2015. These can also be used for other scientific purposes, such as study of variable stars. Aims In this paper we aim assess value MASCARA studying stars determining what extent known recovered and characterised, how well new, unknown variables...
Aims. We describe the design and first light observations from $\beta$ Pictoris b Ring ("bRing") project. The primary goal is to detect photometric variability young star due circumplanetary material surrounding directly imaged extrasolar gas giant planet \bpb. Methods. Over a nine month period centred on September 2017, Hill sphere of will cross in front star, providing unique opportunity probe environment through spectroscopic variations. have built installed two bRing monitoring stations...
Abstract We present the discovery of a highly irradiated and moderately inflated ultrahot Jupiter, TOI-1431b/MASCARA-5 b (HD 201033b), first detected by NASA’s Transiting Exoplanet Survey Satellite mission (TESS) Multi-site All-Sky Camera (MASCARA). The signal was established to be planetary origin through radial velocity measurements obtained using SONG, SOPHIE, FIES, NRES, EXPRES, which show reflex motion K = 294.1 ± 1.1 m s −1 . A joint analysis TESS ground-based photometry reveals that...
Abstract Large-scale exoplanet surveys like the Transiting Exoplanet Survey Satellite (TESS) mission are powerful tools for discovering large numbers of candidates. Single-transit events commonplace within resulting candidate list due to unavoidable limitation observing baseline. These single-transit planets often remain unverified their unknown orbital periods and consequent difficulty in scheduling follow-up observations. In some cases, radial velocity (RV) follow up can constrain period...
Aims: MASCARA and bRing are photometric surveys designed to detect variability caused by exoplanets in stars with $m_V < 8.4$. Such signals typically small require an accurate calibration algorithm, tailored the survey, order be detected. This paper presents methods developed calibrate raw photometry of stations characterizes performance instruments. Methods: For primary a modified version coarse decorrelation algorithm is used, which corrects for extinction due earth's atmosphere, camera...
Photometric monitoring of Beta Pictoris in 1981 showed anomalous fluctuations up to 4% over several days, consistent with foreground material transiting the stellar disk. The subsequent discovery gas giant planet b and predicted transit its Hill sphere within 0.1 au projected distance provided an opportunity search for a circumplanetary disk this $21\pm 4$ Myr-old planetary system. Continuous broadband photometric requires ground-based observatories at multiple longitudes provide redundancy...
In this paper, we aim to characterize a transiting planetary candidate in the southern skies found combined MASCARA and bRing data sets of HD 85628, an A3V star V = 8.2 mag at distance 172 pc, confirm its nature. The was originally detected obtained jointly with instruments using BLS search for transit events. Further photometry taken by 0.7 m CHAT, radial velocity measurements FIDEOS on ESO 1.0 Telescope. High resolution spectra during were CHIRON SMARTS 1.5 telescope target Doppler shadow...
The Near-Infrared Imager and Slitless Spectrograph (NIRISS) is the science module of Canadian-built Fine Guidance Sensor (FGS) onboard James Webb Space Telescope (JWST). NIRISS has four observing modes: 1) broadband imaging featuring seven eight NIRCam filters, 2) wide-field slitless spectroscopy (WFSS) at a resolving power $\sim$150 between 0.8 2.2 $\mu$m, 3) single-object cross-dispersed (SOSS) enabling simultaneous wavelength coverage 0.6 2.8 $\mu$m R$\sim$700, mode optimized for...
Eclipsing binary stars allow derivation of accurate and precise masses radii. When they reside in star clusters, properties even higher precision, along with additional information, can be extracted. Asteroseismology solar-like oscillations offers similar possibilities for single stars. We improve the previously established Hyades eclipsing HD27130 re-assess asteroseismic giant $\epsilon$ Tau. The physical these members are then used to constrain helium content age cluster. New multi-colour...
The bRing robotic observatory network was built to search for circumplanetary material within the transiting Hill sphere of exoplanet $\beta$ Pic b across its bright host star Pic. During survey Pic, it simultaneously monitored brightnesses thousands stars in southern sky ($V$ $\simeq$ 4-8, $\delta$ $\lesssim$ -30$^{\circ}$). In this work, we announce discovery Scuti pulsations A-type HD 156623 using data. is notable as a well-studied young with dusty and gas-rich debris disk, previously...
Abstract In addition to monitoring the bright star β Pic during near-transit event for its giant exoplanet, Pictoris b Ring (bRing) observatories at Siding Springs Observatory, Australia and Sutherland, South Africa have monitored brightnesses of stars ( V ≃ 4–8 mag) centered on south celestial pole δ ≤ −30°) approximately two years. Here we present a comprehensive study bRing time-series photometry southern between 2017 June 2019 January. Of 16,762 by bRing, 353 were found be variable....