Explanipedia

HARPS-N, TESS, and CHEOPS discover a transiting sub-Neptune and two outer companions around the bright solar analogue HD 85426 Open

A. Mortier, A. Collier Cameron, M. Cretignier, A. Anna John, J. A. Egger , et al. · 2025

We provide a detailed characterisation of the planetary system orbiting HD 85426 (TOI-1774). This bright G-type star (M*: 0.99 M⊙; R*: 1.13 R⊙; age: 7.4 Gyr; V mag: 8.25) hosts a transiting sub-Neptune, HD 85426 b, with an orbital period o…

HARPS-N, TESS, and CHEOPS discover a transiting sub-Neptune and two outer companions around the bright solar analogue HD 85426 Open

F. Lienhard, A. M. J. Mortier, A. Collier Cameron, L. Borsato, A. Anna John , et al. · 2025

We provide a detailed characterisation of the planetary system orbiting HD 85426 (TOI-1774). This bright G-type star ($M_{\ast}$: 0.99 $\text{M}_{\odot}$; $R_{\ast}$: 1.13 $\text{R}_{\odot}$; age: 7.4 Gyr; V mag: 8.25) hosts a transiting s…

Detailed cool star flare morphology with CHEOPS and TESS <i>(Corrigendum)</i> Open

G. Bruno, I. Pagano, A. Brandeker, G. Olofsson, A. Fortier , et al. · 2025

Atmospheric composition and circulation of the ultra-hot Jupiter WASP-121b with joint NIRPS, HARPS and CRIRES+ transit spectroscopy Open

Valentina Vaulato, R. Allart, Joost P. Wardenier, H. Chakraborty, D. Ehrenreich , et al. · 2025

Ultra-hot gas giants such as WASP-121b provide unique laboratories for exploring atmospheric chemistry and dynamics under extreme irradiation conditions. Uncovering their chemical composition and atmospheric circulation is critical for tra…

Unveiling the nature of HE 0107-5240 Open

E. Caffau, M. Steffen, P. Molaro, P. Bonifacio, N. Christlieb , et al. · 2025

The vast majority of the most iron-poor stars in the Galaxy exhibit a strong carbon enhancement, with C/H ratios only about two orders of magnitude below solar. This unusual chemical composition likely reflects the properties of the gas cl…

An ultra-short period super-Earth and sub-Neptune spanning the Radius Valley orbiting the kinematic thick disc star TOI-2345 Open

Yoshi Nike Emilia Eschen, T. G. Wilson, A. Bonfanti, C. M. Persson, S. G. Sousa , et al. · 2025

A crucial chemical link between stars and their orbiting exoplanets is thought to exist. If universal, this connection could affect the formation and evolution of all planets. Therefore, this potential vital link needs testing by character…

An Ultra-Short Period Super-Earth and Sub-Neptune Spanning the Radius Valley Orbiting the Kinematic Thick Disk Star TOI-2345 Open

Yoshi Nike Emilia Eschen, T. G. Wilson, A. Bonfanti, C. M. Persson, S. G. Sousa , et al. · 2025

A crucial chemical link between stars and their orbiting exoplanets is thought to exist. If universal, this connection could affect the formation and evolution of all planets. Therefore, this potential vital link needs testing by character…

Cuidado à criança com Síndrome de Down sob à ótica de enfermeiras Open

Rosália Teixeira Luz, Cecília Correia, N. C. Santos, Norma Lopes de Magalhães Velasco Bastos, Marizete Argolo Teixeira · 2025

Conhecer de que forma as enfermeiras das Unidades Básicas de Saúde percebem o cuidado à criança com Síndrome de Down. Trata-se de uma pesquisa de caráter exploratória e descritiva de natureza qualitativa que foi desenvolvida em 4 unidades …

SOAPv4: A new step toward modeling stellar signatures in exoplanet research Open

E. Cristo, J. P. Faria, N. C. Santos, W. Dethier, B. Akinsanmi , et al. · 2025

Context. In the era of high-resolution spectroscopy, methods for characterizing exoplanets and their atmospheres are advancing rapidly. As these techniques are refined and allow for the detection of even the most minute signals from the pl…

NIRPS and TESS reveal a peculiar system around the M dwarf TOI-756: A transiting sub-Neptune and a cold eccentric giant Open

Léna Parc, F. Bouchy, Neil J. Cook, Nolan Grieves, Étienne Artigau , et al. · 2025

Context . 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 p…

Transit timing variations in HIP 41378: CHEOPS and TESS confirm a non-transiting sixth planet in the system Open

P. Leonardi, L. Borsato, L. Pagliaro, Daria Kubyshkina, J.A. Egger , et al. · 2025

In multiple-planet systems, gravitational interactions of exoplanets could lead to transit timing variations (TTVs), whose amplitude becomes significantly enhanced when planets are in or near mean-motion resonances (MMRs), making them more…

ATREIDES Open

V. Bourrier, M. Steiner, A. Castro-González, D. J. Armstrong, O. Attia , et al. · 2025

The distribution of close-in exoplanets is shaped by a complex interplay between atmospheric and dynamical processes. The Desert, Ridge, and Savanna (respectively a lack, overoccurence, and mild deficit of Neptunes with increasing periods)…

Chromaticity of stellar activity in radial velocities Open

P. Larue, X. Delfosse, A. Carmona, N. Meunier, Étienne Artigau , et al. · 2025

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 signals are wavelength-dependent or chromatic, unlike pla…

Three hot Jupiters transiting K-dwarfs with significant heavy element masses Open

Yolanda G. C. Frensch, F. Bouchy, G. Lo Curto, S. Ulmer-Moll, S. G. Sousa , et al. · 2025

Context . Despite predictions from planetary population synthesis models indicating that such systems should be exceedingly rare, short-period gas giants do exist around low-mass stars ( T eff < 4965 K), albeit at lower frequency than arou…

A comprehensive study on radial velocity signals using ESPRESSO: Pushing precision to the 10 cm/s level Open

P. Figueira, J. P. Faria, A. M. Silva, A. Castro-González, J. Gomes da Silva , et al. · 2025

Aims . We analyse ESPRESSO data for the stars HD 10700 ( τ Ceti), HD 20794 ( e Eridani), HD 102365, and HD 304636 acquired via its Guaranteed Time Observations (GTO) programme. We characterise the stars’ radial velocity (RV) signals down t…

Radial velocity homogeneous analysis of M dwarfs observed with HARPS Open

L. Mignon, X. Delfosse, N. Meunier, Guillaume Chaverot, Remo Burn , et al. · 2025

Aims . We aim to 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 rates using the large volume of the sample but …

Studying the variability of the He triplet to understand the detection limits of evaporating exoplanet atmospheres Open

Samson J. Mercier, X. Dumusque, V. Bourrier, Khaled Al Moulla, M. Cretignier , et al. · 2025

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 upcomin…

Hydride ion continuum hides absorption signatures in the NIRPS near-infrared transmission spectrum of the ultra-hot gas giant WASP-189b Open

Valentina Vaulato, Stefan Pelletier, D. Ehrenreich, R. Allart, E. Cristo , et al. · 2025

Context . Ultra-hot Jupiters showcase one-of-a-kind extreme atmospheric conditions, including the dissociation of molecules into atomic species, ionisation, and significant day-to-night temperature contrasts. The proximity to their host st…

Diving into the planetary system of Proxima with NIRPS Open

A. Suárez Mascareño, Étienne Artigau, L. Mignon, X. Delfosse, Neil J. Cook , et al. · 2025

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 ms −1 and a median uncertai…

NIRPS detection of delayed atmospheric escape from the warm and misaligned Saturn-mass exoplanet WASP-69 b Open

R. Allart, Yann Carteret, V. Bourrier, L. Mignon, Frédérique Baron , et al. · 2025

Context . Near-infrared high-resolution échelle 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 …

HD 35843: A Sun-like Star Hosting a Long-period Sub-Neptune and Inner Super-Earth Open

Katharine Hesse, Ismael Mireles, F. Bouchy, Diana Dragomir, Solène Ulmer-Moll , et al. · 2025

We report the discovery and confirmation of two planets orbiting the metal-poor Sun-like star HD 35843 (TOI 4189). HD 35843 c is a temperate sub-Neptune transiting planet with an orbital period of 46.96 days that was first identified by Pl…

Empowering Maritime Spatial Planning and Marine Conservation Efforts Through Digital Engagement: The Role of Online Platforms Open

Débora Gutierrez, Helena Calado, Femke van Toor, Mariana Moreira, Maria Luz Paramio , et al. · 2025

This study addresses the performance of digital platforms in enhancing ocean governance by improving communication and collaboration among stakeholders. It analyses several platforms based on their collaborative initiatives, digital tools,…

A comprehensive study on radial velocity signals using ESPRESSO: Pushing precision to the 10 cm/s level Open

P. Figueira, A. M. Silva, A. Castro-González, J. Gomes da Silva, S. G. Sousa , et al. · 2025

We analyse ESPRESSO data for the stars HD10700, HD20794, HD102365, and HD304636 acquired via its Guaranteed Time Observations (GTO) programme. We characterise the stars' radial velocity (RV) signals down to a precision of 10 cm/s on timesc…

Neither rocky nor icy: Exploring the nature of steam worlds Open

Bárbara Soares, Caroline Dorn, V. Adibekyan, Sérgio Sousa, E. Delgado Mena , et al. · 2025

As the number of exoplanets found gradually increases, so does the types of planets existing, leading to a very diverse population. While the formation processes of some are thought to be known, others remain yet to be explained. Such is t…

A systematic bias in template-based radial velocity extraction algorithms Open

A.M. Silva, N. C. Santos, J. P. Faria, J. H. C. Martins, E. Cristo , et al. · 2025

Context . The radial velocity (RV) method plays a key role in modern-day astrophysics. One of the most common techniques for extracting precise RVs from state-of-the-art spectrographs is template-matching (TM) algorithms. They have been sh…

CORALIE radial-velocity search for companions around evolved stars (CASCADES) Open

E. Fontanet, S. Udry, D. Ségransan, P. Figueira, J.A. Acevedo Barroso , et al. · 2025

Context . 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 companion…

The ESPRESSO transmission spectrum of HD189733 b Open

Dany Mounzer, W. Dethier, C. Lovis, V. Bourrier, Angelica Psaridi , et al. · 2025

Context . While transmission spectroscopy has allowed us to detect many atomic and molecular species in exoplanet atmospheres, the improvement in resolution and signal-to-noise ratio (S/N) enabled us to become sensitive to planet-occulted …

NIRPS joining HARPS at ESO 3.6 m Open

F. Bouchy, R. Doyon, F. Pepe, Claudio Melo, Étienne Artigau , et al. · 2025

Context . The Near-InfraRed Planet Searcher (NIRPS) is a high-resolution, high-stability near-infrared (NIR) spectrograph equipped with an adaptive optics (AO) system. Installed on the ESO 3.6-m telescope at La Silla Observatory, Chile, it…

IA NA EDUCAÇÃO A DISTÂNCIA Open

Silvana Maria Aparecida Viana Santos, Alexandre Azenha Alves de Rezende, Edney Rodrigues Dutra, M. S. Cunha, Maria Lúcia Góes Araujo , et al. · 2025

Este estudo abordou o uso da Inteligência Artificial (IA) nos cursos a distância, analisando suas vantagens, desvantagens e desafios. Partiu-se do problema: quais são as vantagens, desvantagens e desafios do uso da Inteligência Artificial …

The TOI-1117 multiplanetary system: 3 sub-Neptunes, 1 in both the Neptunian Desert and Radius Valley Open

Isobel S Lockley, D. J. Armstrong, Jorge Fernández Fernández, Sarah Millholland, Henrik Knierim , et al. · 2025

We present the discovery of three sub-Neptune planets around TOI-1117, a Sun-like star with mass $0.97\pm 0.02\,{\mathrm M}_{\odot }$, radius $1.05\pm 0.03\,{\mathrm {R}}_{\odot }$, age $4.42\pm 1.50$ Gyr, and effective temperature $5635\p…

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