Publications (20)
Characterisation of stellar activity of M dwarfs. I. Long-timescale variability in a large sample and detection of new cycles
L. Mignon, N. Meunier, X. Delfosse +7
M dwarfs are active stars that exhibit variability in chromospheric emission and photometry at short and long timescales, including long cycles that are related to dynamo processes…
Radial velocity homogeneous analysis of M dwarfs observed with HARPS. II. Detection limits and planetary occurrence statistics
L. Mignon, X. Delfosse, N. Meunier +13
We re-determine planetary occurrences around M dwarfs using 20 years of observations from HARPS on 197 targets. The first aim of this study is to propose more precise occurrence ra…
HD207897 b: A dense sub-Neptune transiting a nearby and bright K-type star
N. Heidari, I. Boisse, J. Orell-Mique +90
We present the discovery and characterization of a transiting sub-Neptune orbiting with a 16.20 day period around a nearby (28 pc) and bright(V=8.37) K0V star HD207897 (TOI-1611).…
The JADE code. II. Modeling the coupled orbital and atmospheric evolution of GJ 436 b to constrain its migration and companion
M. Attia, V. Bourrier, E. Bolmont +5
The observed architecture and modeled evolution of close-in exoplanets provide crucial insights into their formation pathways and survival mechanisms. To investigate these fundamen…
The RoPES project with HARPS and HARPS-N II. A third planet in the multi-planet system HD 176986
N. Nari, A. Suárez Mascareño, J. I. González Hernández +7
Earth-like planets orbiting in the habitable zone of K- to G-type stars create an RV effect in amplitude of less than 1 \si{\meter\per\second} and have orbital periods of hundreds…
A hot terrestrial planet orbiting the bright M dwarf L 168-9 unveiled by TESS
N. Astudillo-Defru, R. Cloutier, S. X. Wang +67
We report the detection of a transiting super-Earth-sized planet (R=1.39+-0.09 Rearth) in a 1.4-day orbit around L 168-9 (TOI-134),a bright M1V dwarf (V=11, K=7.1) located at 25.15…
The SOPHIE search for northern extrasolar planets XIII. Two planets around M-dwarfs Gl617A and Gl96
M. J. Hobson, R. F. DÃaz, X. Delfosse +32
We report the detection of two exoplanets and a further tentative candidate around the M-dwarf stars Gl96 and Gl617A, based on radial velocity measurements obtained with the SOPHIE…
Characterizing planetary systems with SPIRou: Detection of a sub-Neptune in a 6-day period orbit around the M dwarf Gl 410
A. Carmona, X. Delfosse, M. Ould-Elhkim +42
The search for exoplanets around nearby M dwarfs represents a crucial milestone in the census of planetary systems in the vicinity of our Solar System. Since 2018 our team is carry…
Architecture of planetary systems with and without outer giant planets I. Inner planet detections around HD 23079, HD 196067, and HD 86226
J. -B. Delisle, J. P. Faria, D. Ségransan +22
Understanding the link between outer giant planets (OGPs) and inner light planets (ILPs) is key to understanding planetary system formation and architecture. The correlation betwee…
The SOPHIE search for northern extrasolar planets. XIV. A temperate ( K) super-earth around the nearby star Gliese 411
R. F. DÃaz, X. Delfosse, M. J. Hobson +33
Periodic radial velocity variations in the nearby M-dwarf star Gl411 are reported, based on measurements with the SOPHIE spectrograph. Current data do not allow us to distinguish b…
Near-IR and optical radial velocities of the active M dwarf star Gl 388 (AD Leo) with SPIRou at CFHT and SOPHIE at OHP: A 2.23 day rotation period and no evidence for a corotating planet
A. Carmona, X. Delfosse, S. Bellotti +36
Context: The search for extrasolar planets around the nearest M dwarfs is a crucial step towards identifying the nearest Earth-like planets. One of the main challenges in this sear…
The inflated, eccentric warm Jupiter TOI-4914 b orbiting a metal-poor star, and the hot Jupiters TOI-2714 b and TOI-2981 b
G. Mantovan, T. G. Wilson, L. Borsato +32
Recent observations of giant planets have revealed unexpected bulk densities. Hot Jupiters, in particular, appear larger than expected for their masses compared to planetary evolut…
The SOPHIE search for northern extrasolar planets -- XVII. A wealth of new objects: Six cool Jupiters, three brown dwarfs, and 16 low-mass binary stars
S. Dalal, F. Kiefer, G. Hébrard +30
Distinguishing classes within substellar objects and understanding their formation and evolution need larger samples of substellar companions such as exoplanets, brown dwarfs, and…
The SOPHIE search for northern extrasolar planets-XIX. A system including a cold sub-Neptune potentially transiting a V = 6.5 star HD88986
N. Heidari, I. Boisse, N. C. Hara +51
Transiting planets with orbital periods longer than 40 d are extremely rare among the 5000+ planets discovered so far. The lack of discoveries of this population poses a challenge…
Searching for substellar companion candidates with Gaia. III. Search for companions to members of young associations
A. -M. Lagrange, F. Kiefer, P. Rubini +13
Absolute astrometry with Gaia is expected to detect and characterize the orbits of thousands of exoplanets in the coming years. A tool, GaiaPMEX, was recently developed to characte…
The RoPES project with HARPS and HARPS-N III. Two candidate planets orbiting the G-type star HD 161098
N. Nari, A. Suárez Mascareño, J. I. González Hernández +9
Context. The development of refined instruments and techniques for a detailed analysis of the radial velocities (RVs) of stars other than the Sun allows the presence of planetary s…
The SOPHIE search for northern extrasolar planets. XVI. HD 158259: A compact planetary system in a near-3:2 mean motion resonance chain
N. C. Hara, F. Bouchy, M. Stalport +32
Since 2011, the SOPHIE spectrograph has been used to search for Neptunes and super-Earths in the Northern Hemisphere. As part of this observational program, 290 radial velocity mea…
The SOPHIE search for northern extrasolar planets XV. A Warm Neptune around the M-dwarf Gl378
M. J. Hobson, X. Delfosse, N. Astudillo-Defru +31
We present the detection of a Warm Neptune orbiting the M-dwarf Gl378, using radial velocity measurements obtained with the SOPHIE spectrograph at the Observatoire de Haute-Provenc…
Relationship between Ca and H chromospheric emission in F-G-K stars: indication of stellar filaments?
N. Meunier, M. Kretzschmar, R. Gravet +2
Different relationships between the H and Ca II chromospheric emissions have been reported in solar-type stars. In particular, the time-series of emissions in these two lines a…
Variability of stellar granulation and convective blueshift with spectral type and magnetic activity. I. K and G main sequence stars
N. Meunier, A. -M. Lagrange, L. Mbemba Kabuiku +3
In solar-type stars, the attenuation of convective blueshift by stellar magnetic activity dominates the RV variations over the low amplitude signal induced by low mass planets. Mod…