79 citations · 397 across the 38 of their papers we have counts for
32 papers · 1 filter
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…
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…
Monitoring the young planet host V1298 Tau with SPIRou: planetary system and evolving large-scale magnetic field
B. Finociety, J. -F. Donati, P. I. Cristofari +15
We report results of a spectropolarimetric monitoring of the young Sun-like star V1298~Tau based on data collected with the near-infrared spectropolarimeter SPIRou at the Canada-Fr…