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The breaking of cold traps and onset of titanium in ultra-hot Jupiter atmospheres: WASP-189b in context
Authors:
Stefan Pelletier,
Romain Allart,
Valentina Vaulato,
David Ehrenreich,
Eduardo Cristo,
Laurie Dauplaise,
Christophe Lovis,
Leslie Moranta,
Nicolas B. Cowan,
Thierry Forveille,
Étienne Artigau,
Frédérique Baron,
Susana C. C. Barros,
Björn Benneke,
Xavier Bonfils,
François Bouchy,
Marta Bryan,
Bruno L. Canto Martins,
Ryan Cloutier,
Neil J. Cook,
Jose Renan De Medeiros,
Xavier Delfosse,
René Doyon,
Jonay I. González Hernández,
David Lafrenière
, et al. (34 additional authors not shown)
Abstract:
Condensates are ubiquitous to all Solar System planets with significant ($>$10mbar) atmospheres. The same is true for most exoplanets with characterised atmospheres, with even ultra-hot exoplanets being able to form clouds on their cooler nightsides. One high-interest condensate is titanium, a highly refractory element that as an oxide (TiO) is a potent optical absorber long believed to be a drive…
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Condensates are ubiquitous to all Solar System planets with significant ($>$10mbar) atmospheres. The same is true for most exoplanets with characterised atmospheres, with even ultra-hot exoplanets being able to form clouds on their cooler nightsides. One high-interest condensate is titanium, a highly refractory element that as an oxide (TiO) is a potent optical absorber long believed to be a driver of thermal inversions in highly irradiated exoplanet atmospheres. Observations have shown that some ultra-hot Jupiters have strong thermal inversions despite being significantly Ti-depleted, likely due to cold trapping, raising doubts about whether TiO is the main cause of their inverted temperature structures. Our aim was to retrieve the titanium-to-iron ratio of the dayside atmosphere of the ultra-hot Jupiter WASP-189b to determine whether the full titanium budget is accounted for in the gas phase. We analysed thermal emission observations of WASP-189b taken with the HARPS and NIRPS spectrographs using different atmospheric retrieval prescriptions to infer the planet's atmospheric thermal structure and composition. We observed Fe and Ti signals in cross-correlation and measured a sub-solar Ti/Fe ratio for WASP-189b using both free and chemical equilibrium retrieval approaches. We find the Ti/Fe of the planetary atmosphere to be between 28% and 81% (1-$σ$ bounds) that of the stellar value. The slight underabundance of Ti with respect to Fe on the dayside atmosphere of WASP-189b suggests that some titanium is missing from the gas phase, potentially due to a partial nightside cold trap. In the context of the ultra-hot Jupiter population, the onset of titanium in exoplanetary atmospheres appears to occur progressively, coinciding not with when thermal inversions begin but rather when the vapourisation threshold of titanium is reached on the nightside.
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Submitted 14 June, 2026;
originally announced June 2026.
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TOI-3664 b, TOI-4034 b & TOI-6564 b: Three new hot Jupiters around stars approaching the terminal age main sequence
Authors:
Matthew P. Battley,
Marina Lafarga,
Edward Gillen,
Monika Lendl,
Solène Ulmer-Moll,
Cynthia S. K. Ho,
Emilio Marfil,
Sergio Sousa,
Yolanda Frensch,
Dimitri Veras,
François Bouchy,
Yann Carteret,
Ian J. M. Crossfield,
Tyler Fairnington,
Mathilde Houelle,
Dan Huber,
Marziye Jafariyazani,
Léna Parc,
Don Radford,
TG Tan,
Sara Tavella,
Rob Wittenmyer,
Duncan Wright,
George Zhou
Abstract:
Studying the evolution of hot Jupiters requires a sample of well-characterised systems across all evolutionary states. We present three new gas giant exoplanets around stars approaching the end of the main sequence, a comparatively unexplored epoch of hot Jupiter evolution. These planets were discovered by TESS before being vetted and confirmed through dedicated spectroscopic follow-up programmes…
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Studying the evolution of hot Jupiters requires a sample of well-characterised systems across all evolutionary states. We present three new gas giant exoplanets around stars approaching the end of the main sequence, a comparatively unexplored epoch of hot Jupiter evolution. These planets were discovered by TESS before being vetted and confirmed through dedicated spectroscopic follow-up programmes by CARMENES, CORALIE and MINERVA-Australis. TOI-3664 b has a period of 3.30 days, a radius of 1.22 +/- 0.03 RJup and a mass of 0.36 +/- 0.12 MJup. TOI-4034 b is a short-period hot Jupiter with a period of 1.80 days, a radius of 1.58 +/- 0.02 RJup and a mass of 0.87 +/- 0.16 MJup. Meanwhile TOI-6564 b has a period of 3.99 days, radius of 1.46 +/- 0.02 RJup and mass of 0.70 +/- 0.07 MJup. All three planets have radii larger than Jupiter but sub-Jupiter masses, in line with slight inflation as their hosts increase in luminosity towards the end of the main sequence. These exoplanets' low densities and hosts' advanced evolutionary states make them interesting planets with which to study the later stages of hot Jupiter evolution. Careful analysis was undertaken to determine the ages of each system, considering astrometry, gyrochronology, stellar isochrones and lithium abundance, yielding ages of 9.0 +2.4/-2.1 Gyr, 5.7 +/- 0.5 Gyr and 4.0 +/- 1.0 Gyr for TOI-3664, TOI-4034 and TOI-6564 respectively, yet each system has a similar evolutionary state because of their differing stellar masses (0.98 +/- 0.03, 1.19 +0.13/-0.03 and 1.18 +0.16/-0.03 M*). These three planets add more steps to the "age-ladder" of exoplanetary evolution, building towards the community's goal of understanding how planets evolve over time.
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Submitted 16 July, 2026; v1 submitted 3 June, 2026;
originally announced June 2026.
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Super-Earth masses and stellar abundances from NIRPS reveal tentative evidence for water-rich formation around M dwarfs
Authors:
Drew Weisserman,
Nicole Gromek,
Ryan Cloutier,
Komal Bali,
Charles Cadieux,
Mykhaylo Plotnykov,
Alexandrine L'Heureux,
Avidaan Srivastava,
Andres Carmona,
Yolanda G. C. Frensch,
Étienne Artigau,
Frédérique Baron,
Susana C. C. Barros,
Björn Benneke,
Xavier Bonfils,
François Bouchy,
Marta Bryan,
Neil J. Cook,
Nicolas B. Cowan,
Eduardo Cristo,
Xavier Delfosse,
René Doyon,
Xavier Dumusque,
David Ehrenreich,
Jonay I. González Hernández
, et al. (76 additional authors not shown)
Abstract:
Tracing the compositional link between terrestrial super-Earths and their host stars provides clues to their dominant formation pathway. By constraining the stellar abundances of refractory elements, we can predict the core mass fractions (CMFs) of their super-Earths. The level of agreement between this prediction and the planetary CMF derived from their masses and radii can reveal past formation…
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Tracing the compositional link between terrestrial super-Earths and their host stars provides clues to their dominant formation pathway. By constraining the stellar abundances of refractory elements, we can predict the core mass fractions (CMFs) of their super-Earths. The level of agreement between this prediction and the planetary CMF derived from their masses and radii can reveal past formation processes, like mantle stripping and water-rich formation plus sequestration in the planet's core. Here, we present the first results from the Near Infrared Planet Searcher (NIRPS) GTO CMF subprogram: an intensive radial velocity campaign to refine masses and compute host stellar abundances of three hot super- Earths around M dwarfs (GJ 1132 b, GJ 1252 b, and LTT 3780 b), calculating masses of $1.69 \pm 0.15M_\oplus$, $1.54 \pm 0.18M_\oplus$, and $2.34 \pm 0.10M_\oplus$ respectively. We measure the CMFs of these and six further hot super-Earths with precise masses already available in the literature to 10-15% precision. We compare these to CMF predictions made from measuring the Fe, Mg, and Si abundances of their host stars measured from the NIRPS spectra. We find that the CMFs of these planets are smaller than expected from their host stellar abundances, to a statistically significant degree. This discrepancy is suggestive of significant reservoirs of water, and while these planets are too hot to harbor surface water, they likely have interior water mass fractions of $\sim$1%.
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Submitted 8 April, 2026;
originally announced April 2026.
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Confirmation of the hot super-Neptune TOI-672 b with NIRPS and HARPS and Insights into the Neptunian desert around M dwarfs
Authors:
Ares Osborn,
Ryan Cloutier,
Vincent Bourrier,
Bennett Skinner,
Nicole Gromek,
Avidaan Srivastava,
François Bouchy,
Marion Cointepas,
Neil J. Cook,
Nicola Nari,
Jose Manuel Almenara,
'Etienne Artigau,
Xavier Bonfils,
Charles Cadieux,
Patrick Eggenberger,
Alexandrine L'Heureux,
Frédérique Baron,
Susana C. C. Barros,
Björn Benneke,
Marta Bryan,
Bruno L. Canto Martins,
Nicolas B. Cowan,
Eduardo Cristo,
Xavier Delfosse,
Jose Renan De Medeiros
, et al. (43 additional authors not shown)
Abstract:
The Neptunian desert is a distinct lack of Neptune-sized planets at short orbital periods, purportedly carved by photoevaporation and tidal circularization following high-eccentricity migration. Constraining these processes and how they vary across different host-star spectral types requires the detailed characterization of planets in the desert and around its boundaries. In this study, we confirm…
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The Neptunian desert is a distinct lack of Neptune-sized planets at short orbital periods, purportedly carved by photoevaporation and tidal circularization following high-eccentricity migration. Constraining these processes and how they vary across different host-star spectral types requires the detailed characterization of planets in the desert and around its boundaries. In this study, we confirm the planetary nature of a massive super-Neptune identified by TESS around the M0 dwarf TOI-672. We analyse photometry from TESS and ExTrA and precise radial velocity measurements taken with the recently commissioned Near-InfraRed Planet Searcher (NIRPS) and HARPS spectrographs. We measure the planetary orbital period, radius, and mass of 3.634 days, 5.31 +0.24 -0.26 Rearth, and 50.9 +4.5 -4.4 Mearth, respectively. Our findings place TOI-672 b within the Neptunian ridge, a pile-up of planets from 3--5 days at the Neptunian desert boundary. We then use a novel approach to determine the desert boundaries in period-radius space and instellation-radius space, and, for the first time, compare the Neptunian desert boundaries for planets orbiting FGK versus M dwarf stars. We determine that the boundary ridge shifts slightly inward from 3.3 +- 1.4 days for FGK host stars to 2.2 +- 1.0 days for M dwarf host stars; these values do not statistically significantly differ from each other, and the shift to shorter periods for M dwarf planets is smaller than theoretical photoevaporation models predict. We also find that TOI-672 b is a single-planet system within the sensitivity limits of our RV and TTV datasets.
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Submitted 12 March, 2026;
originally announced March 2026.
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Densities of small planets around the M dwarfs TOI-4336 A and TOI-4342 with ESPRESSO: Three sub-Neptunes, one super-Earth, and a Neptune-mass candidate
Authors:
Léna Parc,
Charles Cadieux,
Nolan Grieves,
François Bouchy,
Alexandrine L'Heureux,
Caroline Dorn,
Marie-Luise Steinmeyer,
Elisa Delgado-Mena,
René Doyon,
Yolanda G. C. Frensch,
Romain Allart,
Etienne Artigau,
Nicola Astudillo-Defru,
Xavier Bonfils,
Yann Carteret,
Ryan Cloutier,
Marion Cointepas,
Karen A. Collins,
Jose Renan De Medeiros,
Xavier Delfosse,
Xavier Dumusque,
Tianjun Gan,
Jonay I. González Hernández,
Ravit Helled,
Monika Lendl
, et al. (5 additional authors not shown)
Abstract:
We present the characterization of two planetary systems orbiting the M dwarfs TOI-4336 A (M3.5V) and TOI-4342 (M0V), each hosting two transiting planets previously validated with TESS and ground-based observations. We refined the photometry of the TOI-4342 system using TESS and LCOGT data, and characterized the host stars with NIRPS and ESPRESSO spectroscopy. High-precision ESPRESSO radial veloci…
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We present the characterization of two planetary systems orbiting the M dwarfs TOI-4336 A (M3.5V) and TOI-4342 (M0V), each hosting two transiting planets previously validated with TESS and ground-based observations. We refined the photometry of the TOI-4342 system using TESS and LCOGT data, and characterized the host stars with NIRPS and ESPRESSO spectroscopy. High-precision ESPRESSO radial velocities allowed us to constrain the planetary masses and investigate their potential compositions. The TOI-4336 A system is composed of a sub-Neptune with a period of 16.34 days, a radius of $2.14 \pm 0.08$ Re, and a mass of $3.33 \pm 0.36$ Me, along with an inner super-Earth on a 7.59-day orbit with a radius of $1.25 \pm 0.07$ Re and a mass of $1.55 \pm 0.13$ Me. The TOI-4342 system hosts two sub-Neptunes of similar sizes ($2.33 \pm 0.09$ Re and $2.35 \pm 0.09$ Re), with periods of 5.54 and 10.69 days. Their masses are measured to be $7.3 \pm 1.3$ Me and $4.8 \pm 1.4$ Me, respectively. The RVs also reveal a planet candidate around TOI-4342, likely non-transiting, with a period of 47.5 days and a minimum mass of $17.8 \pm 3.0$ Me. With precise radii and masses, we derived bulk densities and explored possible compositions. The TOI-4336 A sub-Neptune and super-Earth have densities of $1.87 \pm 0.30$ and $4.35 \pm 0.79$ g cm$^{-3}$, while the two similar-sized sub-Neptunes in TOI-4342 show distinct densities of $3.18 \pm 0.67$ and $2.01 \pm 0.63$ g cm$^{-3}$. All four planets are excellent targets for future atmospheric characterization with JWST, and their multi-planet nature makes them especially interesting for comparative planetology. Notably, TOI-4336 A b stands out as one of the best-known targets in its size and temperature regime, with a TSM of 138, comparable to benchmark planets such as K2-18 b and LHS 1140 b.
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Submitted 16 February, 2026; v1 submitted 29 January, 2026;
originally announced January 2026.
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NIRPS tightens the mass estimate of GJ 3090 b and detects a planet near the stellar rotation period
Authors:
Pierrot Lamontagne,
Drew Weisserman,
Charles Cadieux,
David Lafrenière,
Alexandrine L'Heureux,
Mykhaylo Plotnykov,
Léna Parc,
Atanas K. Stefanov,
Leslie Moranta,
René Doyon,
François Bouchy,
Jean-Baptiste Delisle,
Louise D. Nielsen,
Gaspare Lo Curto,
Frédérique Baron,
Susana C. C. Barros,
Björn Benneke,
Xavier Bonfils,
Marta Bryan,
Bruno L. Canto Martins,
Ryan Cloutier,
Nicolas B. Cowan,
Daniel Brito de Freitas,
Jose Renan De Medeiros,
Xavier Delfosse
, et al. (126 additional authors not shown)
Abstract:
We present an updated characterization of the planetary system orbiting the nearby M2 dwarf GJ 3090 (TOI-177; $d = 22$ pc), based on new high-precision radial velocity (RV) observations from NIRPS and HARPS. With an orbital period of 2.85 d, the transiting sub-Neptune GJ 3090 b has a mass we refine to $4.52 \pm 0.47 M_{\oplus}$, which, combined with our derived radius of…
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We present an updated characterization of the planetary system orbiting the nearby M2 dwarf GJ 3090 (TOI-177; $d = 22$ pc), based on new high-precision radial velocity (RV) observations from NIRPS and HARPS. With an orbital period of 2.85 d, the transiting sub-Neptune GJ 3090 b has a mass we refine to $4.52 \pm 0.47 M_{\oplus}$, which, combined with our derived radius of $2.18 \pm 0.06 R_{\oplus}$, yields a density of $2.40^{+0.33}_{-0.30}$ g cm$^{-3}$. The combined interior structure and atmospheric constraints indicate that GJ 3090 b is a compelling water-world candidate, with a volatile-rich envelope in which water likely represents a significant fraction. We also confirm the presence of a second planet, GJ 3090 c, a sub-Neptune with a 15.9 d orbit and a minimum mass of $10.0 \pm 1.3 M_{\oplus}$, which does not transit. Despite its proximity to the star's 18 d rotation period, our joint analysis using a multidimensional Gaussian process (GP) model that incorporates TESS photometry and differential stellar temperature measurements distinguishes this planetary signal from activity-induced variability. In addition, we place new constraints on a non-transiting planet candidate with a period of 12.7 d, suggested in earlier RV analyses. This candidate remains a compelling target for future monitoring. These results highlight the crucial role of multidimensional GP modelling in disentangling planetary signals from stellar activity, enabling the detection of a planet near the stellar rotation period that could have remained undetected with traditional approaches.
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Submitted 20 February, 2026; v1 submitted 14 January, 2026;
originally announced January 2026.
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NIRPS and TESS reveal a peculiar system around the M dwarf TOI-756: A transiting sub-Neptune and a cold eccentric giant
Authors:
Léna Parc,
François Bouchy,
Neil J. Cook,
Nolan Grieves,
Étienne Artigau,
Alexandrine L'Heureux,
René Doyon,
Yuri S. Messias,
Frédérique Baron,
Susana C. C. Barros,
Björn Benneke,
Xavier Bonfils,
Marta Bryan,
Bruno L. Canto Martins,
Ryan Cloutier,
Nicolas B. Cowan,
Daniel Brito de Freitas,
Jose Renan De Medeiros,
Xavier Delfosse,
Elisa Delgado-Mena,
Xavier Dumusque,
David Ehrenreich,
Pedro Figueira,
Jonay I. González Hernández,
David Lafrenière
, et al. (126 additional authors not shown)
Abstract:
The Near InfraRed Planet Searcher (NIRPS) joined HARPS on the 3.6-m ESO telescope at La Silla Observatory in April 2023, dedicating part of its Guaranteed Time Observations (GTO) program to the radial velocity follow-up of TESS planet candidates to confirm and characterize transiting planets around M dwarfs. We report the first results of this program with the characterization of the TOI-756 syste…
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The Near InfraRed Planet Searcher (NIRPS) joined HARPS on the 3.6-m ESO telescope at La Silla Observatory in April 2023, dedicating part of its Guaranteed Time Observations (GTO) program to the radial velocity follow-up of TESS planet candidates to confirm and characterize transiting planets around M dwarfs. We report the first results of this program with the characterization of the TOI-756 system, which consists of TOI-756 b, a transiting sub-Neptune candidate detected by TESS, as well as TOI-756 c, an additional non-transiting planet discovered by NIRPS and HARPS. TOI-756 b is a 1.24-day period sub-Neptune with a radius of 2.81 $\pm$ 0.10 $R_\oplus$ and a mass of 9.8$^{+1.8}_{-1.6}$ $M_\oplus$. TOI-756 c is a cold eccentric (e$_c$ = 0.45 $\pm$ 0.01) giant planet orbiting with a period of 149.6 days around its star with a minimum mass of 4.05 $\pm$ 0.11 $M_\mathrm{jup}$. Additionally, a linear trend of 146$~\mathrm{m\,s}^{-1}\,\mathrm{yr}^{-1}$ is visible in the radial velocities, hinting at a third component, possibly in the planetary or brown dwarf regime. This system is unique in the exoplanet landscape, standing as the first confirmed example of such a planetary architecture around an M dwarf. With a density of 2.42 $\pm$ 0.49 g cm$^{-3}$, the inner planet, TOI-756 b, is a volatile-rich sub-Neptune. Assuming a pure H/He envelope, we inferred an atmospheric mass fraction of 0.023 and a core mass fraction of 0.27, which is well constrained by stellar refractory abundances derived from NIRPS spectra. It falls within the still poorly explored radius cliff and at the lower boundary of the Neptune desert, making it a prime target for a future atmospheric characterization with JWST to improve our understanding of this population.
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Submitted 16 October, 2025;
originally announced October 2025.
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TOI-3288 b and TOI-4666 b: two gas giants transiting low-mass stars characterised by NIRPS
Authors:
Yolanda G. C. Frensch,
François Bouchy,
Gaspare Lo Curto,
Alexandrine L'Heureux,
Roseane de Lima Gomes,
João Faria,
Xavier Dumusque,
Lison Malo,
Marion Cointepas,
Avidaan Srivastava,
Xavier Bonfils,
Elisa Delgado-Mena,
Nicola Nari,
Khaled Al Moulla,
Romain Allart,
Jose M. Almenara,
Étienne Artigau,
Khalid Barkaoui,
Frédérique Baron,
Susana C. C. Barros,
Björn Benneke,
Marta Bryan,
Charles Cadieux,
Bruno L. Canto Martins,
Izan de Castro Leão
, et al. (40 additional authors not shown)
Abstract:
Gas giant planets orbiting low-mass stars are uncommon outcomes of planet formation. Increasing the sample of well-characterised giants around early M dwarfs will enable population-level studies of their properties, offering valuable insights into their formation and evolutionary histories. We aim to characterise giant exoplanets transiting M dwarfs identified by TESS. High-resolution spectroscopi…
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Gas giant planets orbiting low-mass stars are uncommon outcomes of planet formation. Increasing the sample of well-characterised giants around early M dwarfs will enable population-level studies of their properties, offering valuable insights into their formation and evolutionary histories. We aim to characterise giant exoplanets transiting M dwarfs identified by TESS. High-resolution spectroscopic data are obtained in the optical and nIR, combining HARPS and NIRPS. We derive RVs via the cross-correlation function and implement a novel post-processing procedure to further mitigate telluric contamination in the nIR. The resulting RVs are jointly fit with TESS and ground-based photometry to derive the orbital and physical parameters of the systems. We confirm two gas giants transiting the low-mass stars TOI-3288 A (K9V) and TOI-4666 (M2.5V). TOI-3288 A hosts a Hot Jupiter with a mass of $2.11\pm0.08~M_{\rm Jup}$ and a radius of $1.00 \pm 0.03~R_{\rm Jup}$, with an orbital period of 1.43 days ($T_{\rm eq} = 1059 \pm 20~{\rm K}$). TOI-4666 hosts a $0.70_{-0.06}^{+0.05}~M_{\rm Jup}$ warm Jupiter ($T_{\rm eq} = 713 \pm 14~{\rm K}$) with a radius of $1.11 \pm 0.04~R_{\rm Jup}$, and an orbital period of 2.91 days. We identify a decrease in planetary mass with spectral type, where late M dwarfs host less massive giant planets than early M dwarfs. More massive gas giants that deviate from this trend are preferentially hosted by more metal-rich stars. Furthermore, we find an increased binarity fraction among low-mass stars hosting gas giants, which may play a role in enhancing giant planet formation around low-mass stars. The observed population trends agree with theoretical expectations, where higher metallicity can compensate for lower disk masses, and wide binary systems may influence planet formation and migration through Kozai-Lidov cycles or disk instabilities.
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Submitted 22 December, 2025; v1 submitted 13 October, 2025;
originally announced October 2025.
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Architecture of planetary systems with and without outer giant planets I. Inner planet detections around HD 23079, HD 196067, and HD 86226
Authors:
J. -B. Delisle,
J. P. Faria,
D. Ségransan,
E. Fontanet,
W. Ceva,
D. Barbato,
S. G. Sousa,
N. Unger,
A. Leleu,
F. Bouchy,
M. Cretignier,
R. F. Díaz,
X. Dumusque,
Y. G. C. Frensch,
N. C. Hara,
G. Laughlin,
G. Lo Curto,
C. Lovis,
M. Marmier,
M. Mayor,
L. Mignon,
C. Mordasini,
F. Pepe,
N. C. Santos,
S. Udry
Abstract:
Understanding the link between outer giant planets (OGPs) and inner light planets (ILPs) is key to understanding planetary system formation and architecture. The correlation between these two populations of planets is debated both theoretically -- different formation models predict either a correlation or an anticorrelation -- and observationally. Several recent attempts to constrain this correlat…
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Understanding the link between outer giant planets (OGPs) and inner light planets (ILPs) is key to understanding planetary system formation and architecture. The correlation between these two populations of planets is debated both theoretically -- different formation models predict either a correlation or an anticorrelation -- and observationally. Several recent attempts to constrain this correlation have yielded contradictory results, due to small-number statistics and heterogeneous samples. We present an ongoing long-term observational effort with CORALIE, HARPS, and ESPRESSO to probe the ILP occurrence in systems with and without OGP. In this first article of a series, we discuss how, from the design to the observations, we ensured the homogeneity of the samples, both in terms of stellar properties and observing strategy. We also present the first three detections of ILPs in our OGP host sample. We find a 8.3 mE planet at 5.75 d around HD 23079, a 10.4 mE planet at 4.6 d around HD 196067, and we confirm the 7.5 mE planet at 3.98 d around HD 86226. While a rigorous statistical analysis of our samples will be performed in subsequent studies, the relatively low number of detections in our sample seems to contradict previous studies that found a strong OGP-ILP correlation.
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Submitted 30 September, 2025;
originally announced September 2025.
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Atmospheric composition and circulation of the ultra-hot Jupiter WASP-121b with joint NIRPS, HARPS and CRIRES+ transit spectroscopy
Authors:
Valentina Vaulato,
Melissa J. Hobson,
Romain Allart,
Stefan Pelletier,
Joost P. Wardenier,
Hritam Chakraborty,
David Ehrenreich,
Nicola Nari,
Michal Steiner,
Xavier Dumusque,
H. Jens Hoeijmakers,
Étienne Artigau,
Frédérique Baron,
Susana C. C. Barros,
Björn Benneke,
Xavier Bonfils,
François Bouchy,
Marta Bryan,
Bruno L. Canto Martins,
Ryan Cloutier,
Neil J. Cook,
Nicolas B. Cowan,
Jose Renan De Medeiros,
Xavier Delfosse,
Elisa Delgado-Mena
, et al. (35 additional authors not shown)
Abstract:
Ultra-hot Jupiters like WASP-121b provide unique laboratories for studying atmospheric chemistry and dynamics under extreme irradiation. Constraining their composition and circulation is key to tracing planet formation pathways. We present a comprehensive characterisation of WASP-121b using high-resolution transit spectroscopy from HARPS, NIRPS, and CRIRES+ across nine transits, complemented by fi…
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Ultra-hot Jupiters like WASP-121b provide unique laboratories for studying atmospheric chemistry and dynamics under extreme irradiation. Constraining their composition and circulation is key to tracing planet formation pathways. We present a comprehensive characterisation of WASP-121b using high-resolution transit spectroscopy from HARPS, NIRPS, and CRIRES+ across nine transits, complemented by five TESS sectors, two EulerCam light curves simultaneous with HARPS/NIRPS, and an extensive RV dataset refining orbital parameters. Cross-correlation detects Fe, CO, and V with SNRs of 5.8, 5.0, and 4.7, respectively. Retrieval analysis constrains H$_2$O to $-6.52^{+0.49}_{-0.68}$ dex, though its signal might be muted by the H$^-$ continuum. We measure volatile/refractory ratios, key to uncover planetary chemistry, evolution, and formation. Retrieved values align with solar composition in chemical equilibrium, suggesting minimal disequilibrium chemistry at the probed pressures (around $10^{-4}$-$10^{-3}$ bar). We update WASP-121b's orbital parameters analysing its largest RV dataset to date. Comparing orbital velocities from RVs and atmospheric retrieval reveals a non-zero circulation offset, $\mathrm{ΔK}_{\mathrm{p}} = -15 \pm 3 \ \mathrm{km}\mathrm{s}^{-1}$ (assuming $\mathrm{M}_{\star} = 1.38 \pm 0.02 \ \mathrm{M}_{\odot}$), consistent with drag-free or weak-drag 3D GCM predictions, though sensitive to stellar mass. These results provide new constraints on WASP-121b's thermal structure, dynamics, and chemistry, underscoring the power of multi-instrument and multi-wavelength high-resolution spectroscopy to probe exoplanet atmospheres.
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Submitted 29 August, 2025;
originally announced September 2025.
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Quantifying thermal water dissociation in the dayside photosphere of WASP-121 b using NIRPS
Authors:
Luc Bazinet,
Romain Allart,
Björn Benneke,
Stefan Pelletier,
Joost P. Wardenier,
Neil J. Cook,
Thierry Forveille,
Louise D. Nielsen,
Khaled Al Moulla,
Étienne Artigau,
Frédérique Baron,
Susana C. C. Barros,
Xavier Bonfils,
François Bouchy,
Marta Bryan,
Bruno L. Canto Martins,
Ryan Cloutier,
Nicolas B. Cowan,
Daniel Brito de Freitas,
Jose Renan De Medeiros,
Xavier Delfosse,
René Doyon,
Xavier Dumusque,
David Ehrenreich,
Jonay I. González Hernández
, et al. (97 additional authors not shown)
Abstract:
The intense stellar irradiation of ultra-hot Jupiters results in some of the most extreme atmospheric environments in the planetary regime. On their daysides, temperatures can be sufficiently high for key atmospheric constituents to thermally dissociate into simpler molecular species and atoms. This dissociation drastically changes the atmospheric opacities and, in turn, critically alters the temp…
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The intense stellar irradiation of ultra-hot Jupiters results in some of the most extreme atmospheric environments in the planetary regime. On their daysides, temperatures can be sufficiently high for key atmospheric constituents to thermally dissociate into simpler molecular species and atoms. This dissociation drastically changes the atmospheric opacities and, in turn, critically alters the temperature structure, atmospheric dynamics, and day-night heat transport. To this date, however, simultaneous detections of the dissociating species and their thermally dissociation products in exoplanet atmospheres have remained rare. Here we present the simultaneous detections of H$_2$O and its thermally dissociation product OH on the dayside of the ultra-hot Jupiter WASP-121 b based on high-resolution emission spectroscopy with the recently commissioned Near InfraRed Planet Searcher (NIRPS). We retrieve a photospheric abundance ratio of log$_{10}$(OH/H$_2$O) $= -0.15\pm{0.20}$ indicating that there is about as much OH as H$_2$O at photospheric pressures, which confirms predictions from chemical equilibrium models. We compare the dissociation on WASP-121 b with other ultra-hot Jupiters and show that a trend in agreement with equilibrium models arises. We also discuss an apparent velocity shift of $4.79^{+0.93}_{-0.97} $km s$^{-1}$ in the H$_2$O signal, which is not reproduced by current global circulation models. Finally, in addition to H$_2$O and OH, the NIRPS data reveal evidence of Fe and Mg, from which we infer a Fe/Mg ratio consistent with the solar and host star ratios. Our results demonstrate that NIRPS can be an excellent instrument to obtain simultaneous measurements of refractory and volatile molecular species, paving the way for many future studies on the atmospheric composition, chemistry, and the formation history of close-in exoplanets.
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Submitted 8 August, 2025;
originally announced August 2025.
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NIRPS joining HARPS at ESO 3.6 m. On-sky performance and science objectives
Authors:
Francois Bouchy,
Rene Doyon,
Francesco Pepe,
Claudio Melo,
Etienne Artigau,
Lison Malo,
Francois Wildi,
Frederique Baron,
Xavier Delfosse,
Jose Renan De Medeiros,
Rafael Rebolo,
Nuno C. Santos,
Gregg Wade,
Romain Allart,
Khaled Al Moulla,
Nicolas Blind,
Charles Cadieux,
Bruno L. Canto Martins,
Neil J. Cook,
Xavier Dumusque,
Yolanda Frensch,
Frederic Genest,
Jonay I. Gonzalez Hernandez,
Nolan Grieves,
Gaspare Lo Curto
, et al. (109 additional authors not shown)
Abstract:
The Near-InfraRed Planet Searcher (NIRPS) is a high-resolution, high-stability near-infrared (NIR) spectrograph equipped with an AO system. Installed on the ESO 3.6-m telescope, it was developed to enable radial velocity (RV) measurements of low-mass exoplanets around M dwarfs and to characterise exoplanet atmospheres in the NIR. This paper provides a comprehensive design overview and characterisa…
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The Near-InfraRed Planet Searcher (NIRPS) is a high-resolution, high-stability near-infrared (NIR) spectrograph equipped with an AO system. Installed on the ESO 3.6-m telescope, it was developed to enable radial velocity (RV) measurements of low-mass exoplanets around M dwarfs and to characterise exoplanet atmospheres in the NIR. This paper provides a comprehensive design overview and characterisation of the NIRPS instrument, reporting on its on-sky performance, and presenting its GTO programme. The instrument started its operations on 1 Apr 2023 after intensive on-sky testing phases. The spectral range continuously covers the Y, J, and H bands from 972.4 to 1919.6 nm. The thermal control system maintains 1 mK stability over several months. The NIRPS AO-assisted fibre link improves coupling efficiency and offers a unique high-angular resolution capability with a fibre acceptance of only 0.4 arcsec. A high spectral resolving power of 90 000 and 75 000 is provided in HA and HE modes, respectively. The overall throughput from the top of the atmosphere to the detector peaks at 13 percent. The RV precision, measured on the bright star Proxima with a known exoplanetary system, is 77 cm/s. NIRPS and HARPS can be used simultaneously, offering unprecedented spectral coverage for spectroscopic characterisation and stellar activity mitigation. Modal noise can be aptly mitigated by the implementation of fibre stretchers and AO scanning mode. Initial results confirm that NIRPS opens new possibilities for RV measurements, stellar characterisation, and exoplanet atmosphere studies with high precision and high spectral fidelity. NIRPS demonstrated stable RV precision at the level of 1 m/s over several weeks. The instrument high throughput offers a notable improvement over previous spectrographs, enhancing our ability to detect small exoplanets.
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Submitted 29 July, 2025;
originally announced July 2025.
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Diving into the planetary system of Proxima with NIRPS -- Breaking the metre per second barrier in the infrared
Authors:
Alejandro Suárez Mascareño,
Étienne Artigau,
Lucile Mignon,
Xavier Delfosse,
Neil J. Cook,
François Bouchy,
René Doyon,
Jonay I. González Hernández,
Thomas Vandal,
Izan de Castro Leão,
Atanas K. Stefanov,
João Faria,
Charles Cadieux,
Pierrot Lamontagne,
Frédérique Baron,
Susana C. C. Barros,
Björn Benneke,
Xavier Bonfils,
Marta Bryan,
Bruno L. Canto Martins,
Ryan Cloutier,
Nicolas B. Cowan,
Daniel Brito de Freitas,
Jose Renan De Medeiros,
Elisa Delgado-Mena
, et al. (116 additional authors not shown)
Abstract:
We obtained 420 high-resolution spectra of Proxima, over 159 nights, using the Near Infra Red Planet Searcher (NIRPS). We derived 149 nightly binned radial velocity measurements with a standard deviation of 1.69 m/s and a median uncertainty of 55 cm/s, and performed a joint analysis combining radial velocities, spectroscopic activity indicators, and ground-based photometry, to model the planetary…
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We obtained 420 high-resolution spectra of Proxima, over 159 nights, using the Near Infra Red Planet Searcher (NIRPS). We derived 149 nightly binned radial velocity measurements with a standard deviation of 1.69 m/s and a median uncertainty of 55 cm/s, and performed a joint analysis combining radial velocities, spectroscopic activity indicators, and ground-based photometry, to model the planetary and stellar signals present in the data, applying multi-dimensional Gaussian process regression to model the activity signals. We detect the radial velocity signal of Proxima b in the NIRPS data. All planetary characteristics are consistent with those previously derived using visible light spectrographs. In addition, we find evidence of the presence of the sub-Earth Proxima d in the NIRPS data. When combining the data with the HARPS observations taken simultaneous to NIRPS, we obtain a tentative detection of Proxima d and parameters consistent with those measured with ESPRESSO. By combining the NIRPS data with simultaneously obtained HARPS observations and archival data, we confirm the existence of Proxima d, and demonstrate that its parameters are stable over time and against change of instrument. We refine the planetary parameters of Proxima b and d, and find inconclusive evidence of the signal attributed to Proxima c (P = 1900 d) being present in the data. We measure Proxima b and d to have minimum masses of 1.055 $\pm$ 0.055 Me, and 0.260 $\pm$ 0.038 Me, respectively. Our results show that, in the case of Proxima, NIRPS provides more precise radial velocity data than HARPS, and a more significant detection of the planetary signals. The standard deviation of the residuals of NIRPS after the fit is 80 cm/s, showcasing the potential of NIRPS to measure precise radial velocities in the near-infrared.
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Submitted 29 July, 2025;
originally announced July 2025.
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Studying the variability of the He triplet to understand the detection limits of evaporating exoplanet atmospheres
Authors:
Samson J. Mercier,
Xavier Dumusque,
Vincent Bourrier,
Khaled Al Moulla,
Michael Cretignier,
William Dethier,
Gaspare Lo Curto,
Pedro Figueira,
Christophe Lovis,
Francesco Pepe,
Nuno C. Santos,
Stéphane Udry,
François Wildi,
Romain Allart,
Frédérique Baron,
François Bouchy,
Andres Carmona,
Marion Cointepas,
René Doyon,
Yolanda Frensch,
Nolan Grieves,
Lucile Mignon,
Louise D. Nielsen
Abstract:
With more than a dozen significant detections, the helium triplet has emerged as a key tracer of evaporating exoplanet atmospheres. This near-infrared feature can be observed from the ground and holds great promise, especially with upcoming observations provided by new-generation instruments such as the Near Infrared Planet Searcher (NIRPS). However, as the helium triplet is also present in stella…
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With more than a dozen significant detections, the helium triplet has emerged as a key tracer of evaporating exoplanet atmospheres. This near-infrared feature can be observed from the ground and holds great promise, especially with upcoming observations provided by new-generation instruments such as the Near Infrared Planet Searcher (NIRPS). However, as the helium triplet is also present in stellar spectra, careful removal of the average stellar contribution is necessary to accurately characterize the atmospheres of transiting exoplanets. In this study, we analyze multi-epoch observations of the Sun obtained with NIRPS to investigate the temporal variability of the helium triplet. Our findings reveal significant variability across different timescales, ranging from minutes to days. We identify telluric contamination and stellar activity as likely sources for the short-term and long-term variability, respectively. Importantly, we demonstrate that this variability has minimal impact on the retrieval of planetary parameters crucial to the study of atmospheric escape.
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Submitted 28 July, 2025;
originally announced July 2025.
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NIRPS detection of delayed atmospheric escape from the warm and misaligned Saturn-mass exoplanet WASP-69b
Authors:
Romain Allart,
Yann Carteret,
Vincent Bourrier,
Lucile Mignon,
Frederique Baron,
Charles Cadieux,
Andres Carmona,
Christophe Lovis,
Hritam Chakraborty,
Elisa Delgado-Mena,
Etienne Artigau,
Susana C. C. Barros,
Bjorn Benneke,
Xavier Bonfils,
Francois Bouchy,
Marta Bryan,
Bruno L. Canto Martins,
Ryan Cloutier,
Neil J. Cook,
Nicolas B. Cowan,
Xavier Delfosse,
Rene Doyon,
Xavier Dumusque,
David Ehrenreich,
Jonay I. Gonzalez Hernandez
, et al. (97 additional authors not shown)
Abstract:
Near-infrared high-resolution echelle spectrographs unlock access to fundamental properties of exoplanets, from their atmospheric escape and composition to their orbital architecture, which can all be studied simultaneously from transit observations. We present the first results of the newly commissioned ESO near-infrared spectrograph, NIRPS, from three transits of WASP-69b. We used the RM Revolut…
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Near-infrared high-resolution echelle spectrographs unlock access to fundamental properties of exoplanets, from their atmospheric escape and composition to their orbital architecture, which can all be studied simultaneously from transit observations. We present the first results of the newly commissioned ESO near-infrared spectrograph, NIRPS, from three transits of WASP-69b. We used the RM Revolutions technique to better constrain the orbital architecture of the system. We extracted the high-resolution helium absorption profile to study its spectral shape and temporal variations. Then, we made 3D simulations from the EVE code to fit the helium absorption time series. We measure a slightly misaligned orbit for WASP-69b (psi of 28.7+/-5.7 deg). We confirm the detection of helium with an average excess absorption of 3.17+/-0.05%. The helium absorption is spectrally and temporally resolved, extends to high altitudes and has a strong velocity shift up to -29.5+/-2.5 km/s 50 minutes after egress. EVE simulations put constraints on the mass loss of 2.25 10^11 g/s and hint at reactive chemistry within the cometary-like tail and interaction with the stellar winds that allow the metastable helium to survive longer than expected. Our results suggest that WASP-69b is undergoing a transformative phase in its history, losing mass while evolving on a misaligned orbit. This work shows how combining multiple observational tracers such as orbital architecture, atmospheric escape, and composition, is critical to understand exoplanet demographics and their formation and evolution. We demonstrate that NIRPS can reach precisions similar to HARPS for RM studies, and the high data quality of NIRPS leads to unprecedented atmospheric characterization. The high stability of NIRPS combined with the large GTO available for its consortium, enables in-depth studies of exoplanets as well as large population surveys.
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Submitted 28 July, 2025;
originally announced July 2025.
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Blind search for activity-sensitive lines in the near-infrared using HARPS and NIRPS observations of Proxima and Gl 581
Authors:
João Gomes da Silva,
Elisa Delgado-Mena,
Nuno C. Santos,
Telmo Monteiro,
Pierre Larue,
Alejandro Suárez Mascareño,
Xavier Delfosse,
Lucile Mignon,
Étienne Artigau,
Nicola Nari,
Manuel Abreu,
José L. A. Aguiar,
Khaled Al Moulla,
Guillaume Allain,
Romain Allart,
Tomy Arial,
Hugues Auger,
Frédérique Baron,
Susana C. C. Barros,
Luc Bazinet,
Björn Benneke,
Nicolas Blind,
David Bohlender,
Isabelle Boisse,
Xavier Bonfils
, et al. (123 additional authors not shown)
Abstract:
Stellar activity variability is one of the main obstacles to the detection of Earth-like planets using the RV method. The aim of this work is to measure the effect of activity in the spectra of M dwarfs and detect activity-sensitive lines in the NIR. We took advantage of the simultaneous observations of HARPS and the newly commissioned NIRPS spectrograph to carry out a blind search of the most act…
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Stellar activity variability is one of the main obstacles to the detection of Earth-like planets using the RV method. The aim of this work is to measure the effect of activity in the spectra of M dwarfs and detect activity-sensitive lines in the NIR. We took advantage of the simultaneous observations of HARPS and the newly commissioned NIRPS spectrograph to carry out a blind search of the most activity-sensitive spectral lines in the NIR using NIRPS spectra and known activity indicators in the optical from HARPS as a reference. We analysed the spectra of Proxima (M5.5V) and Gl 581 (M3V), two M dwarfs with different activity levels and internal structures. Spectral lines were identified for both stars and their profiles were fitted using different models. We found hundreds of lines sensitive to activity for both stars; the Proxima spectra were more affected. For Proxima, 32% of the identified lines can be used to measure the rotation period of the star, while for Gl 581 the numbers drops to 1%. The fraction of lines sensitive to activity increases with increasing line depth. A list of 17 lines with rotation period detection for both stars is provided. Stellar activity is able to affect a significant number of spectral lines in the NIR, and methods should be developed to mitigate those effects at the spectral level. The line distortions detected here are expected to come mainly from the flux effect due to temperature contrasts between active regions and the quiet photosphere; however, we cannot rule out the possibility that core-emission from chromospheric activity or Zeeman splitting are also affecting some lines. The new line lists presented here can be used to improve the RV extraction and the detection of RV variability due to stellar activity signals, and to help false positive detection and the modelling of activity variability, thereby enhancing exoplanet detection in the NIR.
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Submitted 28 July, 2025;
originally announced July 2025.
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Hydride ion continuum hides absorption signatures in the NIRPS near-infrared transmission spectrum of the ultra-hot gas giant WASP-189b
Authors:
Valentina Vaulato,
Stefan Pelletier,
David Ehrenreich,
Romain Allart,
Eduardo Cristo,
Michal Steiner,
Xavier Dumusque,
Hritam Chakraborty,
Monika Lendl,
Avidaan Srivastava,
Étienne Artigau,
Frédérique Baron,
C. Susana Barros,
Björn Benneke,
Xavier Bonfils,
François Bouchy,
Marta Bryan,
Bruno L. Canto Martins,
Ryan Cloutier,
Neil J. Cook,
Nicolas B. Cowan,
Jose Renan De Medeiros,
Xavier Delfosse,
René Doyon,
I. Jonay González Hernández
, et al. (55 additional authors not shown)
Abstract:
Ultra-hot Jupiters showcase extreme atmospheric conditions, including molecular dissociation, ionisation, and significant day-to-night temperature contrasts. Their close proximity to host stars subjects them to intense stellar irradiation, driving high temperatures where hydride ions (H$^-$) significantly contribute to opacity, potentially obscuring metal features in near-infrared transmission spe…
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Ultra-hot Jupiters showcase extreme atmospheric conditions, including molecular dissociation, ionisation, and significant day-to-night temperature contrasts. Their close proximity to host stars subjects them to intense stellar irradiation, driving high temperatures where hydride ions (H$^-$) significantly contribute to opacity, potentially obscuring metal features in near-infrared transmission spectra. We investigate the atmosphere of WASP-189b, targeting atomic, ionic, and molecular species (H, He, Fe, Ti, V, Mn, Na, Mg, Ca, Cr, Ni, Y, Ba, Sc, Fe$^+$, Ti$^+$, TiO, H$_2$O, CO, and OH), focusing on (i) the role of H$^-$ as a source of continuum opacity, and (ii) the relative hydride-to-Fe abundance using joint optical and near-infrared data. We present two transits of WASP-189b gathered simultaneously in the optical with HARPS and near-infrared with NIRPS, supported by photometric light curves from EulerCam and ExTrA. Transmission spectra were analysed via cross-correlation to detect absorption features and enhance the signal-to-noise ratio. Atmospheric retrievals quantified relative abundances by fitting overall metallicity and proxies for TiO, H$^-$, and e$^-$. Only atomic iron is detected in HARPS data (S/N ~5.5), but not in NIRPS, likely due to H$^-$ continuum dampening. Retrievals on HARPS-only and HARPS+NIRPS suggest the hydride-to-Fe ratio exceeds equilibrium predictions by about 0.5 dex, hinting at strong hydrogen ionisation. Including NIRPS data helps constrain H$^-$ abundance and set an upper limit on free electron density, unconstrained in HARPS-only data. These results emphasise H$^-$ as a significant continuum opacity source impeding detection of planetary absorption features in WASP-189b's near-infrared transmission spectrum.
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Submitted 28 July, 2025;
originally announced July 2025.
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Three Hot Jupiters transiting K-dwarfs with a significant heavy element mass
Authors:
Y. G. C. Frensch,
F. Bouchy,
G. Lo Curto,
S. Ulmer-Moll,
S. G. Sousa,
N. C. Santos,
K. G. Stassun,
C. N. Watkins,
H. Chakraborty,
K. Barkaoui,
M. Battley,
W. Ceva,
K. A. Collins,
T. Daylan,
P. Evans,
J. P. Faria,
C. Farret Jentink,
E. Fontanet,
E. Fridén,
G. Furesz,
M. Gillon,
N. Grieves,
C. Hellier,
E. Jehin,
J. M. Jenkins
, et al. (28 additional authors not shown)
Abstract:
Albeit at a lower frequency than around hotter stars, short-period gas giants around low-mass stars ($T_\mathrm{eff} < 4965$ K) do exist, despite predictions from planetary population synthesis models that such systems should be exceedingly rare. By combining data from TESS and ground-based follow-up observations, we seek to confirm and characterize giant planets transiting K dwarfs, particularly…
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Albeit at a lower frequency than around hotter stars, short-period gas giants around low-mass stars ($T_\mathrm{eff} < 4965$ K) do exist, despite predictions from planetary population synthesis models that such systems should be exceedingly rare. By combining data from TESS and ground-based follow-up observations, we seek to confirm and characterize giant planets transiting K dwarfs, particularly mid/late K dwarfs. Photometric data were obtained from the TESS mission, supplemented by ground-based imaging- and photometric observations, as well as high-resolution spectroscopic data from the CORALIE spectrograph. Radial velocity (RV) measurements were analyzed to confirm the presence of companions. We report the confirmation and characterization of three giants transiting mid-K dwarfs. Within the TOI-2969 system, a giant planet of $1.16\pm 0.04\,M_\mathrm{Jup}$ and a radius of $1.10 \pm 0.08\,R_\mathrm{Jup}$ revolves around its K3V host in 1.82 days. The system of TOI-2989 contains a $3.0 \pm 0.2\,M_\mathrm{Jup}$ giant with a radius of $1.12 \pm 0.05\,R_\mathrm{Jup}$, which orbits its K4V host in 3.12 days. The K4V TOI-5300 hosts a giant of $0.6 \pm 0.1\,M_\mathrm{Jup}$ with a radius of $0.88 \pm 0.08\,R_\mathrm{Jup}$ and an orbital period of 2.3 days. The equilibrium temperatures of the companions range from 1001 to 1186 K, classifying them as Hot Jupiters. However, they do not present radius inflation. The estimated heavy element masses in their interior, inferred from the mass, radius, and evolutionary models, are $90 \pm 30\,M_\oplus$, $114 \pm 30\,M_\oplus$, and $84 \pm 21\,M_\oplus$, respectively. The heavy element masses are significantly higher than most reported heavy elements for K-dwarf Hot Jupiters. These mass characterizations contribute to the poorly explored population of massive companions around low-mass stars.
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Submitted 5 June, 2025;
originally announced June 2025.
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CORALIE radial-velocity search for companions around evolved stars (CASCADES) IV: New planetary systems around HD 87816, HD 94890, and HD 102888 and an update on HD 121056
Authors:
E. Fontanet,
S. Udry,
D. Ségransan,
P. Figueira,
J. A. Acevedo Barroso,
B. Akinsanmi,
M. Attia,
M. Battley,
S. Bhatnagar,
M. Bugatti,
Y. Carteret,
H. Chakraborty,
A. Deline,
C. Farret Jentink,
Y. G. C. Frensch,
M. Houelle,
B. Lavie,
C. Lovis,
M. Mayor,
A. Nigioni,
G. Ottoni,
F. Pepe,
D. J. M. Petit dit de la Roche,
M. Shinde,
N. C. Santos
, et al. (3 additional authors not shown)
Abstract:
With around 200 detections of exoplanets around giant stars to date, our knowledge of the population of exoplanets orbiting evolved hosts more massive than the Sun remains limited. The CORALIE radial-velocity search for companions around evolved stars (CASCADES) was launched in 2006 with the aim of improving our understanding of the demographics of exoplanets around intermediate-mass stars, by stu…
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With around 200 detections of exoplanets around giant stars to date, our knowledge of the population of exoplanets orbiting evolved hosts more massive than the Sun remains limited. The CORALIE radial-velocity search for companions around evolved stars (CASCADES) was launched in 2006 with the aim of improving our understanding of the demographics of exoplanets around intermediate-mass stars, by studying them once they have evolved off the main sequence. We intend to refine the current sample of known exoplanets orbiting intermediate-mass (1.5 - 5 M$_\odot$) giant stars of spectral types G and early K. We searched for exoplanets orbiting the four stars HD 87816, HD 94890, HD 102888, and HD 121056. We used data obtained with the CORALIE spectrograph, mounted on the Leonhard Euler Swiss telescope located at La Silla Observatory in Chile. We gathered high-precision radial-velocity measurements over more than ten years for each of the aforementioned targets. We started by performing a search for periodic signals in the radial-velocity time series of the four targets by using periodograms. Following this, we fit for a Keplerian model using the significant peak with the highest power of the periodogram as the starting guess for the period. We then subtracted this model and repeated the procedure iteratively on the residuals until no significant peaks were found. Finally, to explore the posterior distribution of our models, the final solution was determined using a Markov chain Monte Carlo approach. We report the discovery of five new massive planets around HD 87816, HD 94890, and HD 102888 as well as the presence of a distant, potentially substellar, companion around HD 102888. We confirm the presence of a previously announced exoplanet orbiting the HD 121056 multi-object system with a period of 89 days and propose an update to the period of the outer companion.
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Submitted 23 June, 2025; v1 submitted 20 May, 2025;
originally announced May 2025.
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Discovery of a cold giant planet and mass measurement of a hot super-Earth in the multi-planetary system WASP-132
Authors:
N. Grieves,
F. Bouchy,
D. J. Armstrong,
B. Akinsanmi,
A. Psaridi,
S. Ulmer-Moll,
Y. G. C. Frensch,
R. Helled,
S. Muller,
H. Knierim,
N. C. Santos,
V. Adibekyan,
L. Parc,
M. Lendl,
M. P. Battley,
N. Unger,
G. Chaverot,
D. Bayliss,
X. Dumusque,
F. Hawthorn,
P. Figueira,
M. A. F. Keniger,
J. Lillo-Box,
L. D. Nielsen,
A. Osborn
, et al. (3 additional authors not shown)
Abstract:
Hot Jupiters generally do not have nearby planet companions, as they may have cleared out other planets during their inward migration from more distant orbits. This gives evidence that hot Jupiters more often migrate inward via high-eccentricity migration due to dynamical interactions between planets rather than more dynamically cool migration mechanisms through the protoplanetary disk. Here we fu…
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Hot Jupiters generally do not have nearby planet companions, as they may have cleared out other planets during their inward migration from more distant orbits. This gives evidence that hot Jupiters more often migrate inward via high-eccentricity migration due to dynamical interactions between planets rather than more dynamically cool migration mechanisms through the protoplanetary disk. Here we further refine the unique system of WASP-132 by characterizing the mass of the recently validated 1.0-day period super-Earth WASP-132c (TOI-822.02), interior to the 7.1-day period hot Jupiter WASP-132b. Additionally, we announce the discovery of a giant planet at a 5-year period (2.7 AU). We also detected a long-term trend in the radial velocity data indicative of another outer companion. Using over nine years of CORALIE radial velocities (RVs) and over two months of highly sampled HARPS RVs, we determined the masses of the planets from smallest to largest orbital period to be M$_{\rm{c}}$ = $6.26^{+1.84}_{-1.83}$ $M_{\oplus}$, M$_{\rm{b}}$ = $0.428^{+0.015}_{-0.015}$ $M_{\rm{Jup}}$, and M$_{\rm{d}}\sin{i}$ = $5.16^{+0.52}_{-0.52}$ $M_{\rm{Jup}}$, respectively. Using TESS and CHEOPS photometry data, we measured the radii of the two inner transiting planets to be R$_{\rm{c}}$ = $1.841^{+0.094}_{-0.093}$ $R_{\oplus}$ and R$_{\rm{b}}$ = $0.901^{+0.038}_{-0.038}$ $R_{\rm{Jup}}$. We find a bulk density of $ρ_{\rm{c}}$ = $5.47^{+1.96}_{-1.71}$ g cm$^{-3}$ for WASP-132 c, which is slightly above the Earth-like composition line on the mass-radius diagram. WASP-132 is a unique multi-planetary system in that both an inner rocky planet and an outer giant planet are in a system with a hot Jupiter. This suggests it migrated via a rarer dynamically cool mechanism and helps to further our understanding of how hot Jupiter systems form and evolve.
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Submitted 22 February, 2025; v1 submitted 22 June, 2024;
originally announced June 2024.
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NIRPS first light and early science: breaking the 1 m/s RV precision barrier at infrared wavelengths
Authors:
Étienne Artigau,
François Bouchy,
René Doyon,
Frédérique Baron,
Lison Malo,
François Wildi,
Franceso Pepe,
Neil J. Cook,
Simon Thibault,
Vladimir Reshetov,
Xavier Dumusque,
Christophe Lovis,
Danuta Sosnowska,
Bruno L. Canto Martins,
Jose Renan De Medeiros,
Xavier Delfosse,
Nuno Santos,
Rafael Rebolo,
Manuel Abreu,
Guillaume Allain,
Romain Allart,
Hugues Auger,
Susana Barros,
Luc Bazinet,
Nicolas Blind
, et al. (89 additional authors not shown)
Abstract:
The Near-InfraRed Planet Searcher or NIRPS is a precision radial velocity spectrograph developed through collaborative efforts among laboratories in Switzerland, Canada, Brazil, France, Portugal and Spain. NIRPS extends to the 0.98-1.8 $μ$m domain of the pioneering HARPS instrument at the La Silla 3.6-m telescope in Chile and it has achieved unparalleled precision, measuring stellar radial velocit…
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The Near-InfraRed Planet Searcher or NIRPS is a precision radial velocity spectrograph developed through collaborative efforts among laboratories in Switzerland, Canada, Brazil, France, Portugal and Spain. NIRPS extends to the 0.98-1.8 $μ$m domain of the pioneering HARPS instrument at the La Silla 3.6-m telescope in Chile and it has achieved unparalleled precision, measuring stellar radial velocities in the infrared with accuracy better than 1 m/s. NIRPS can be used either stand-alone or simultaneously with HARPS. Commissioned in late 2022 and early 2023, NIRPS embarked on a 5-year Guaranteed Time Observation (GTO) program in April 2023, spanning 720 observing nights. This program focuses on planetary systems around M dwarfs, encompassing both the immediate solar vicinity and transit follow-ups, alongside transit and emission spectroscopy observations. We highlight NIRPS's current performances and the insights gained during its deployment at the telescope. The lessons learned and successes achieved contribute to the ongoing advancement of precision radial velocity measurements and high spectral fidelity, further solidifying NIRPS' role in the forefront of the field of exoplanets.
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Submitted 13 June, 2024; v1 submitted 12 June, 2024;
originally announced June 2024.
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Discovery of two warm mini-Neptunes with contrasting densities orbiting the young K3V star TOI-815
Authors:
Angelica Psaridi,
Hugh Osborn,
François Bouchy,
Monika Lendl,
Léna Parc,
Nicolas Billot,
Christopher Broeg,
Sérgio G. Sousa,
Vardan Adibekyan,
Omar Attia,
Andrea Bonfanti,
Hritam Chakraborty,
Karen A. Collins,
Jeanne Davoult,
Elisa Delgado-Mena,
Nolan Grieves,
Tristan Guillot,
Alexis Heitzmann,
Ravit Helled,
Coel Hellier,
Jon M. Jenkins,
Henrik Knierim,
Andreas Krenn,
JackJ. Lissauer,
Rafael Luque
, et al. (108 additional authors not shown)
Abstract:
We present the discovery and characterization of two warm mini-Neptunes transiting the K3V star TOI-815 in a K-M binary system. Analysis of the spectra and rotation period reveal it to be a young star with an age of $200^{+400}_{-200}$Myr. TOI-815b has a 11.2-day period and a radius of 2.94$\pm$0.05$\it{R_{\rm\mathrm{\oplus}}}$ with transits observed by TESS, CHEOPS, ASTEP, and LCOGT. The outer pl…
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We present the discovery and characterization of two warm mini-Neptunes transiting the K3V star TOI-815 in a K-M binary system. Analysis of the spectra and rotation period reveal it to be a young star with an age of $200^{+400}_{-200}$Myr. TOI-815b has a 11.2-day period and a radius of 2.94$\pm$0.05$\it{R_{\rm\mathrm{\oplus}}}$ with transits observed by TESS, CHEOPS, ASTEP, and LCOGT. The outer planet, TOI-815c, has a radius of 2.62$\pm$0.10$\it{R_{\rm\mathrm{\oplus}}}$, based on observations of three non-consecutive transits with TESS, while targeted CHEOPS photometry and radial velocity follow-up with ESPRESSO were required to confirm the 35-day period. ESPRESSO confirmed the planetary nature of both planets and measured masses of 7.6$\pm$1.5 $\it{M_{\rm \mathrm{\oplus}}}$ ($ρ_\mathrm{P}$=1.64$^{+0.33}_{-0.31}$gcm$^{-3}$) and 23.5$\pm$2.4$\it{M_{\rm\mathrm{\oplus}}}$ ($ρ_\mathrm{P}$=7.2$^{+1.1}_{-1.0}$gcm$^{-3}$) respectively. Thus, the planets have very different masses, unlike the usual similarity of masses in compact multi-planet systems. Moreover, our statistical analysis of mini-Neptunes orbiting FGK stars suggests that weakly irradiated planets tend to have higher bulk densities compared to those suffering strong irradiation. This could be ascribed to their cooler atmospheres, which are more compressed and denser. Internal structure modeling of TOI-815b suggests it likely has a H-He atmosphere constituting a few percent of the total planet mass, or higher if the planet is assumed to have no water. In contrast, the measured mass and radius of TOI-815c can be explained without invoking any atmosphere, challenging planetary formation theories. Finally, we infer from our measurements that the star is viewed close to pole-on, which implies a spin-orbit misalignment at the 3$σ$ level.
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Submitted 30 January, 2024; v1 submitted 28 January, 2024;
originally announced January 2024.
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New Mass and Radius Constraints on the LHS 1140 Planets -- LHS 1140 b is Either a Temperate Mini-Neptune or a Water World
Authors:
Charles Cadieux,
Mykhaylo Plotnykov,
René Doyon,
Diana Valencia,
Farbod Jahandar,
Lisa Dang,
Martin Turbet,
Thomas J. Fauchez,
Ryan Cloutier,
Collin Cherubim,
Étienne Artigau,
Neil J. Cook,
Billy Edwards,
Tim Hallatt,
Benjamin Charnay,
François Bouchy,
Romain Allart,
Lucile Mignon,
Frédérique Baron,
Susana C. C. Barros,
Björn Benneke,
B. L. Canto Martins,
Nicolas B. Cowan,
J. R. De Medeiros,
Xavier Delfosse
, et al. (21 additional authors not shown)
Abstract:
The two-planet transiting system LHS 1140 has been extensively observed since its discovery in 2017, notably with $Spitzer$, HST, TESS, and ESPRESSO, placing strong constraints on the parameters of the M4.5 host star and its small temperate exoplanets, LHS 1140 b and c. Here, we reanalyse the ESPRESSO observations of LHS 1140 with the novel line-by-line framework designed to fully exploit the radi…
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The two-planet transiting system LHS 1140 has been extensively observed since its discovery in 2017, notably with $Spitzer$, HST, TESS, and ESPRESSO, placing strong constraints on the parameters of the M4.5 host star and its small temperate exoplanets, LHS 1140 b and c. Here, we reanalyse the ESPRESSO observations of LHS 1140 with the novel line-by-line framework designed to fully exploit the radial velocity content of a stellar spectrum while being resilient to outlier measurements. The improved radial velocities, combined with updated stellar parameters, consolidate our knowledge on the mass of LHS 1140 b (5.60$\pm$0.19 M$_{\oplus}$) and LHS 1140 c (1.91$\pm$0.06 M$_{\oplus}$) with unprecedented precision of 3%. Transits from $Spitzer$, HST, and TESS are jointly analysed for the first time, allowing us to refine the planetary radii of b (1.730$\pm$0.025 R$_{\oplus}$) and c (1.272$\pm$0.026 R$_{\oplus}$). Stellar abundance measurements of refractory elements (Fe, Mg and Si) obtained with NIRPS are used to constrain the internal structure of LHS 1140 b. This planet is unlikely to be a rocky super-Earth as previously reported, but rather a mini-Neptune with a $\sim$0.1% H/He envelope by mass or a water world with a water-mass fraction between 9 and 19% depending on the atmospheric composition and relative abundance of Fe and Mg. While the mini-Neptune case would not be habitable, a water-abundant LHS 1140 b potentially has habitable surface conditions according to 3D global climate models, suggesting liquid water at the substellar point for atmospheres with relatively low CO$_2$ concentration, from Earth-like to a few bars.
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Submitted 18 December, 2023; v1 submitted 23 October, 2023;
originally announced October 2023.
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The HARPS search for southern extra-solar planets. XLVII. Five Jupiter-mass planets in long-period orbits, one highly irradiated Neptune, one brown dwarf, and five stellar binaries
Authors:
Y. G. C. Frensch,
G. Lo Curto,
F. Bouchy,
M. Mayor,
G. Hébrard,
C. Lovis,
C. Moutou,
F. A. Pepe,
D. Queloz,
N. Santos,
D. Segransan,
S. Udry,
N. Unger
Abstract:
Our aim is to detect and characterise long-period companions around main sequence stars (spectral types late F to early M). We use the RV method to search for exoplanets around stars. The RV variations are measured with HARPS at the ESO 3.6 metre telescope. The true mass and inclination of our heavier companions are provided by astrometry, for which we use proper motions from Hipparcos and Gaia. F…
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Our aim is to detect and characterise long-period companions around main sequence stars (spectral types late F to early M). We use the RV method to search for exoplanets around stars. The RV variations are measured with HARPS at the ESO 3.6 metre telescope. The true mass and inclination of our heavier companions are provided by astrometry, for which we use proper motions from Hipparcos and Gaia. Five Jupiter-mass exoplanets are reported to orbit HIP54597, BD-210397 (x2), HD74698, and HD94771 with 8.9 yr, 5.2 yr, 17.4 yr, 9.4 yr, and 5.9 yr orbits, and to have minimum masses of $2.01 \pm 0.03$, $0.7 \pm 0.1$, $2.4^{+1.5}_{-0.2}$, $0.40 \pm 0.06$, and $0.53 \pm 0.03 M_J$ respectively. HD74698 also hosts a highly irradiated Neptune in a 15 day orbit with a minimum mass of $0.07 \pm 0.01 M_J$. The mass of HIP54597 b can maximally increase by 10% - 30%, the minimum mass of HD74698 c is likely equal to its true mass, and BD-210397 c has a mass of $2.66^{+0.63}_{-0.32} M_J$. HD62364 hosts a brown dwarf with a true mass of $18.77^{+0.66}_{-0.63} M_J$ in an orbit of 14 yr. HD56380B, HD221638B, and HD33473C have minimum masses within the brown dwarf limits, in orbits of 8.9 yr, 16.6 yr, and 50 yr respectively; however, astrometric measurements reveal them to be stellar binaries, with masses of $375.3^{+8.6}_{-8.4}$, $110.0^{+3.9}_{-3.7}$, and $271.0^{+3.9}_{-3.8} M_J$. The orbits of the stellar binaries HD11938 and HD61383 are incomplete. The preliminary result for HD61383 is a 0.190 $M_{\odot}$ binary in a 39 yr orbit. The secondary of the binary system HD11938 has a mass of 0.33 $M_{\odot}$ - which is confirmed by a secondary peak in the CCF - and a preliminary period of 35 yr. The origin of the 3.0 yr RV signal of HD3964 is uncertain as it shows entanglement with the magnetic cycle of the star. We finally report one more star, HD11608, with a magnetic cycle that mimics a planetary signal.
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Submitted 7 June, 2023;
originally announced June 2023.