Baptiste Klein
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View article: A Decade of Solar High-Fidelity Spectroscopy and Precise Radial Velocities from HARPS-N
A Decade of Solar High-Fidelity Spectroscopy and Precise Radial Velocities from HARPS-N Open
We recently released 10 years of HARPS-N solar telescope and the goal of this manuscript is to present the different optimisations made to the data reduction, to describe data curation, and to perform some analyses that demonstrate the ext…
View article: Using Doppler imaging to model stellar activity and search for planets around Sun-like stars
Using Doppler imaging to model stellar activity and search for planets around Sun-like stars Open
Doppler imaging (DI) is a well-established technique to map a physical field at a stellar surface from a time series of high-resolution spectra. In this proof-of-concept study, we aim to show that traditional DI algorithms, originally desi…
View article: The magnetic and spin-down properties of slowly rotating fully convective M dwarfs
The magnetic and spin-down properties of slowly rotating fully convective M dwarfs Open
The evolution of the magnetism, winds and rotation of low-mass stars are all linked. One of the most common ways to probe the magnetic properties of low-mass stars is with the Zeeman-Doppler imaging (ZDI) technique. The magnetic properties…
View article: The magnetic and spin-down properties of slowly rotating fully convective M dwarfs
The magnetic and spin-down properties of slowly rotating fully convective M dwarfs Open
The evolution of the magnetism, winds, and rotation of low-mass stars are all linked. One of the most common ways to probe the magnetic properties of low-mass stars is with the Zeeman–Doppler imaging (ZDI) technique. The magnetic propertie…
View article: Measuring the Sun’s radial velocity variability due to supergranulation over a magnetic cycle.
Measuring the Sun’s radial velocity variability due to supergranulation over a magnetic cycle. Open
In recent years, supergranulation has emerged as one of the biggest challenges for the detection of Earth-twins in radial velocity planet searches. We used eight years of Sun-as-a-star radial velocity observations from HARPS-N to measure t…
View article: Full Stokes magnetometry of the active M dwarfs AU Mic and EV Lac with SPIRou
Full Stokes magnetometry of the active M dwarfs AU Mic and EV Lac with SPIRou Open
We report in this paper circularly and linearly polarized observations of the young active M dwarfs AU Mic and EV Lac with the near-infrared SPIRou spectropolarimeter at the Canada–France–Hawaii Telescope, collected from August to October …
View article: Measuring the Suns radial velocity variability due to supergranulation over a magnetic cycle
Measuring the Suns radial velocity variability due to supergranulation over a magnetic cycle Open
In recent years supergranulation has emerged as one of the biggest challenges for the detection of Earth-twins in radial velocity planet searches. We used eight years of Sun-as-a-star radial velocity observations from HARPS-N to measure th…
View article: gr8stars – I. A homogeneous spectroscopic study of bright FGKM dwarfs and a public library of their high-resolution spectra
gr8stars – I. A homogeneous spectroscopic study of bright FGKM dwarfs and a public library of their high-resolution spectra Open
As the fields of stellar and exoplanetary study grow and revolutionary new detection instruments are created, it is imperative that a homogeneous, precise source of stellar parameters is available. This first work of the gr8stars collabora…
View article: A possible misaligned orbit for the young planet AU Mic c
A possible misaligned orbit for the young planet AU Mic c Open
The AU Microscopii planetary system is only 24 Myr old, and its geometry may provide clues about the early dynamical history of planetary systems. Here, we present the first measurement of the Rossiter–McLaughlin effect for the warm sub-Ne…
View article: A Gaussian process model for stellar activity in 2D line profile time-series
A Gaussian process model for stellar activity in 2D line profile time-series Open
Stellar active regions like spots and faculae can distort the shapes of spectral lines, inducing variations in the radial velocities that are often orders of magnitude larger than the signals from Earth-like planets. Efforts to mitigate th…
View article: A Gaussian process model for stellar activity in 2-D line profile time-series
A Gaussian process model for stellar activity in 2-D line profile time-series Open
Stellar active regions like spots and faculae can distort the shapes of spectral lines, inducing variations in the radial velocities that are often orders of magnitude larger than the signals from Earth-like planets. Efforts to mitigate th…
View article: Revisiting the dynamical masses of the transiting planets in the young AU Mic system: Potential AU Mic b inflation at ~20 Myr
Revisiting the dynamical masses of the transiting planets in the young AU Mic system: Potential AU Mic b inflation at ~20 Myr Open
Context . Understanding planet formation is important in the context of the origin of planetary systems in general and of the Solar System in particular, as well as to predict the likelihood of finding Jupiter, Neptune, and Earth analogues…
View article: The mean longitudinal magnetic field and its uses in radial-velocity surveys
The mean longitudinal magnetic field and its uses in radial-velocity surveys Open
This work focuses on the analysis of the mean longitudinal magnetic field as a stellar activity tracer in the context of small exoplanet detection and characterization in radial-velocity (RV) surveys. We use Solar Dynamics Observatory/Heli…
View article: Probing atmospheric escape through metastable He I triplet lines in 15 exoplanets observed with SPIRou
Probing atmospheric escape through metastable He I triplet lines in 15 exoplanets observed with SPIRou Open
For several years, the metastable helium triplet line has been successfully used as a tracer to probe atmospheric escape in transiting exoplanets. This absorption in the near-infrared (1083.3 nm) can be observed from the ground using high-…
View article: Probing atmospheric escape through metastable He I triplet lines in 15 exoplanets observed with SPIRou
Probing atmospheric escape through metastable He I triplet lines in 15 exoplanets observed with SPIRou Open
For several years, the metastable helium triplet line has been successfully used as a tracer to probe atmospheric escape in transiting exoplanets. This absorption in the near-infrared (1083.3 nm) can be observed from the ground using high-…
View article: TOI-837 b is a young Saturn-sized exoplanet with a massive 70 M⊕ core
TOI-837 b is a young Saturn-sized exoplanet with a massive 70 M⊕ core Open
We present an exhaustive photometric and spectroscopic analysis of TOI-837, a F9/G0 35 Myr young star, hosting a transiting exoplanet, TOI-837 b, with an orbital period of ∼8.32 d. Utilizing data from the Transiting Exoplanet Survey Satell…
View article: Investigating stellar activity through eight years of Sun-as-a-star observations
Investigating stellar activity through eight years of Sun-as-a-star observations Open
Stellar magnetic activity induces both distortions and Doppler-shifts in the absorption line profiles of Sun-like stars. Those effects produce apparent radial velocity (RV) signals which greatly hamper the search for potentially habitable,…
View article: Investigating stellar activity through eight years of Sun-as-a-star observations
Investigating stellar activity through eight years of Sun-as-a-star observations Open
Stellar magnetic activity induces both distortions and Doppler-shifts in the absorption line profiles of Sun-like stars. Those effects produce apparent radial velocity (RV) signals which greatly hamper the search for potentially habitable,…
View article: Planet Hunters TESS. V. A Planetary System Around a Binary Star, Including a Mini-Neptune in the Habitable Zone
Planet Hunters TESS. V. A Planetary System Around a Binary Star, Including a Mini-Neptune in the Habitable Zone Open
We report on the discovery and validation of a transiting long-period mini-Neptune orbiting a bright ( V = 9.0 mag) G dwarf (TOI 4633; R = 1.05 R ⊙ , M = 1.10 M ⊙ ). The planet was identified in data from the Transiting Exoplanet Survey Sa…
View article: Atmospherix
Atmospherix Open
Measuring the abundances of C- and O-bearing species in exoplanet atmospheres enables us to constrain the C/O ratio, which contains indications about the planet formation history. With a wavelength coverage going from 0.95 to 2.5 µm, the h…
View article: Long-term monitoring of large-scale magnetic fields across optical and near-infrared domains with ESPaDOnS, Narval, and SPIRou
Long-term monitoring of large-scale magnetic fields across optical and near-infrared domains with ESPaDOnS, Narval, and SPIRou Open
Context. Dynamo models describing the generation of stellar magnetic fields for partly and fully convective stars are guided by observational constraints. Zeeman-Doppler imaging has revealed a variety of magnetic field geometries and, for …
View article: Long-term monitoring of large-scale magnetic fields across optical and near-infrared domains with ESPaDOnS, Narval and SPIRou. The cases of EV Lac, DS Leo, and CN Leo
Long-term monitoring of large-scale magnetic fields across optical and near-infrared domains with ESPaDOnS, Narval and SPIRou. The cases of EV Lac, DS Leo, and CN Leo Open
Dynamo models of stellar magnetic fields for partly and fully convective stars are guided by observational constraints. Zeeman-Doppler imaging has revealed a variety of magnetic field geometries and, for fully convective stars in particula…
View article: Modelling stellar variability in archival HARPS data: I - Rotation and activity properties with multidimensional Gaussian processes
Modelling stellar variability in archival HARPS data: I - Rotation and activity properties with multidimensional Gaussian processes Open
Although instruments for measuring the radial velocities (RVs) of stars now routinely reach sub-metre per second accuracy, the detection of low-mass planets is still very challenging. The rotational modulation and evolution of spots and/or…
View article: Modelling stellar variability in archival HARPS data: I -- Rotation and activity properties with multi-dimensional Gaussian Processes
Modelling stellar variability in archival HARPS data: I -- Rotation and activity properties with multi-dimensional Gaussian Processes Open
Although instruments for measuring the radial velocities (RVs) of stars now routinely reach sub-meter per second accuracy, the detection of low-mass planets is still very challenging. The rotational modulation and evolution of spots and/or…
View article: ATMOSPHERIX: I- an open source high-resolution transmission spectroscopy pipeline for exoplanets atmospheres with SPIRou
ATMOSPHERIX: I- an open source high-resolution transmission spectroscopy pipeline for exoplanets atmospheres with SPIRou Open
Atmospheric characterization of exoplanets from the ground is an actively growing field of research. In this context, we have created the ATMOSPHERIX consortium: a research project aimed at characterizing exoplanets atmospheres using groun…
View article: ATMOSPHERIX: II- Characterizing exoplanet atmospheres through transmission spectroscopy with SPIRou
ATMOSPHERIX: II- Characterizing exoplanet atmospheres through transmission spectroscopy with SPIRou Open
In a companion paper, we introduced a publicly available pipeline to characterize exoplanet atmospheres through high-resolution spectroscopy. In this paper, we use this pipeline to study the biases and degeneracies that arise in atmospheri…
View article: ATMOSPHERIX: I- An open source high resolution transmission spectroscopy pipeline for exoplanets atmospheres with SPIRou
ATMOSPHERIX: I- An open source high resolution transmission spectroscopy pipeline for exoplanets atmospheres with SPIRou Open
Atmospheric characterisation of exoplanets from the ground is an actively growing field of research. In this context we have created the ATMOSPHERIX consortium: a research project aimed at characterizing exoplanets atmospheres using ground…
View article: ATMOSPHERIX: II- Characterising exoplanet atmospheres through transmission spectroscopy with SPIRou
ATMOSPHERIX: II- Characterising exoplanet atmospheres through transmission spectroscopy with SPIRou Open
In a companion paper, we introduced a publicly-available pipeline to characterise exoplanet atmospheres through high-resolution spectroscopy. In this paper, we use this pipeline to study the biases and degeneracies that arise in atmospheri…
View article: Vanadium oxide and a sharp onset of cold-trapping on a giant exoplanet
Vanadium oxide and a sharp onset of cold-trapping on a giant exoplanet Open
View article: Wapiti: A data-driven approach to correct for systematics in RV data
Wapiti: A data-driven approach to correct for systematics in RV data Open
Context . Recent advances in the development of precise radial velocity (RV) instruments in the near-infrared (near-IR) domain, such as SPIRou, have facilitated the study of M-type stars to more effectively characterize planetary systems. …