79 citations · 397 across the 38 of their papers we have counts for
38 papers
Unstable magnetospheric accretion on the T Tauri star TW Hya
J. -F. Donati, P. I. Cristofari, C. Moutou +9
In this paper we present new spectropolarimetric and velocimetric observations of the prototypical classical T Tauri star TW Hya obtained with SPIRou at the Canada-France-Hawaii Te…
Magnetic geometry of M dwarfs in the southern PLATO field
M. Diez, P. I. Cristofari, J. Morin +9
M dwarfs are the most abundant stars in the Galaxy and exhibit diverse magnetic behaviours. Understanding their large-scale magnetic fields is essential to study stellar dynamos an…
A fast method for deriving relative small-scale magnetic field variations from high-resolution spectroscopy
Paul I. Cristofari, Steven H. Saar, Aline A. Vidotto +1
Observational constraints on stellar magnetic fields are essential to both stellar and planetary physics. Recent studies revealed the diversity and evolution of large-scale magneti…
Magnetic field measurements in a sample of Class I and flat-spectrum protostars observed with SPIRou
L. Drouglazet, E. Alecian, A. Sousa +27
Magnetic fields play a crucial role throughout stellar evolution, regulating angular momentum, channelling accretion, and launching jets and outflows. While the magnetic properties…
Monitoring the magnetospheric accretion of the classical T Tauri star DO Tau with SPIRou
J. -F. Donati, P. I. Cristofari, A. Carmona +11
We present observations of the classical T Tauri star DO Tau collected with the near-infrared SPIRou spectropolarimeter and precision velocimeter at the Canada-France-Hawaii Telesc…
Betelgeuse: Detection of the Expanding Wake of the Companion Star
Andrea K. Dupree, Paul I. Cristofari, Morgan MacLeod +1
Recent analyses conclude that Betelgeuse, a red supergiant star (HD 39801), likely has a companion object with a period of about 2000 days orbiting at only 2.3 stellar radii, deep…
Searching for close-in planets around TWA 7 with SPIRou
J. -F. Donati, P. I. Cristofari, C. Moutou +7
We outline in this paper observations of the young pre-main-sequence low-mass star TWA 7, hosting a debris disk and a distant planet. Using data collected with the near-infrared SP…
A magnetic field study of two fast-rotating, radio bright M dwarfs. StKM 1-1262 and V374 Peg
S. Bellotti, P. I. Cristofari, J. R. Callingham +8
Radio observations at low frequencies are sensitive to the magnetic activity of stars and the plasma environment surrounding them. The accurate interpretation of the processes unde…
Radio Burst from a Stellar Coronal Mass Ejection
J. R. Callingham, C. Tasse, R. Keers +15
Coronal mass ejections (CMEs) are massive expulsions of magnetised plasma from a star, and are the largest contributors to space weather in the Solar System. CMEs are theorized to…
Characterizing planetary systems with SPIRou: questions about the magnetic cycle of 55 Cnc A and two new planets around B
C. Moutou, P. Petit, P. Charpentier +12
One of the first exoplanet hosts discovered thirty years ago, the star 55 Cnc has been constantly observed ever since. It is now known to host at least five planets with orbital pe…
Chromaticity of stellar activity in radial velocities : Anti-correlated families of lines on the M dwarf EV Lac with SPIRou and SOPHIE
Pierre Larue, Xavier Delfosse, Andres Carmona +33
Context. In the search for exoplanets using radial velocities (RV), stellar activity has become one of the main limiting factors for detectability. Fortunately, activity-induced RV…
Rotational modulation and long-term evolution of the small-scale magnetic fields of M dwarfs observed with SPIRou
P. I. Cristofari, J. -F. Donati, S. Bellotti +7
M dwarfs are known to host magnetic fields, impacting exoplanet studies and playing a key role in stellar and planetary formation and evolution. Observations revealed the long-term…
Spectroscopic Confirmation: Fast rotators in the young clusters NGC 1856 and NGC 1953
Paul I. Cristofari, Andrea K. Dupree, Antonino P. Milone +2
We present the results of a spectroscopic investigation of two Large Magellanic Cloud globular clusters, NGC 1953 and NGC 1856. Both clusters have similar ages (250 and 300 Myr, re…
Full Stokes magnetometry of the active M dwarfs AU Mic and EV Lac with SPIRou
J. -F. Donati, P. I. Cristofari, B. Klein +2
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…
Six-yr SPIRou monitoring of the young planet-host dwarf AU Mic
J. -F. Donati, P. I. Cristofari, C. Moutou +10
In this paper we revisit our spectropolarimetric and velocimetric analysis of the young M dwarf AU Mic based on data collected with SPIRou at the Canada-France-Hawaii telescope, ov…
Mass, Gas, and Gauss around a T Tauri Star with SPIRou
J. -F. Donati, E. Gaidos, C. Moutou +4
Studies of young planets help us understand planet evolution and investigate important evolutionary processes such as atmospheric escape. We monitored IRAS 04125+2902, a 3 Myr-old…
Chemical Links between a Young M-type T Tauri Star and its Substellar Companion: Spectral Analysis and C/O Measurement of DH Tau A
Neda Hejazi, Jerry W. Xuan, David R. Coria +5
The chemical abundance measurements of host stars and their substellar companions provide a powerful tool to trace the formation mechanism of the planetary systems. We present a de…
SPIRou observations of the young planet-hosting star PDS 70
J. -F. Donati, P. I. Cristofari, S. H. P. Alencar +14
This paper presents near-infrared spectropolarimetric and velocimetric observations of the young planet-hosting T Tauri star PDS 70, collected with SPIRou at the 3.6m Canada-France…
Measuring Sub-Kelvin Variations in Stellar Temperature with High-Resolution Spectroscopy
Étienne Artigau, Charles Cadieux, Neil J. Cook +11
The detection of stellar variability often relies on the measurement of selected activity indicators such as coronal emission lines and non-thermal emissions. On the flip side, the…
SPIRou monitoring of the protostar V347 Aur: binarity, magnetic fields, pulsed dynamo and accretion
J. -F. Donati, P. I. Cristofari, A. Carmona +1
We present in this paper an analysis of near-infrared observations of the 0.3-Msun protostar V347 Aur collected with the SPIRou high-resolution spectropolarimeter and velocimeter a…
Rotation and H emission in a young SMC cluster: a spectroscopic view of NGC 330
Paul I. Cristofari, Andrea K. Dupree, Antonino P. Milone +4
We present an analysis of high-resolution optical spectra recorded for 30 stars of the split extended main-sequence turnoff (eMSTO) of the young ( 40 Myr) Small Magellanic Cl…
SPIRou spectropolarimetry of the T Tauri star TW Hydrae: magnetic fields, accretion and planets
J. -F. Donati, P. I. Cristofari, L. T. Lehmann +15
In this paper we report near-infrared observations of the classical T Tauri star TW Hya with the SPIRou high-resolution spectropolarimeter and velocimeter at the 3.6-m Canada-Franc…
The classical T Tauri star CI Tau observed with SPIRou: magnetospheric accretion and planetary formation
J. -F. Donati, B. Finociety, P. I. Cristofari +15
We report new observations of the classical T~Tauri star CI~Tau with the SPIRou near-infrared spectropolarimeter and velocimeter at the Canada-France-Hawaii Telescope (CFHT) in lat…
Measuring small-scale magnetic fields of 44 M dwarfs from SPIRou spectra with ZeeTurbo
P. I. Cristofari, J. -F. Donati, C. Moutou +11
We present the results of an analysis aimed at probing the small-scale magnetic fields of M dwarfs observed with SPIRou, the nIR high-resolution spectro-polarimeter installed at th…