CHEOPS Archives

Phase-folded RVs from the best-fit informed RV model with GPs removed. Binned data shown by the large, purple points (10 bins). Phasefolded on the period of the planet (12.761421 d). -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Venus

The Mass Of The Exo-Venus Gliese 12 b, As Revealed By HARPS-N, ESPRESSO, And CARMENES

by Keith CowingJune 27, 2025September 18, 2025

Small temperate planets are prime targets for exoplanet studies due to their possible similarities with the rocky planets in the Solar System.

Overview of the CHEOPS operational chain. The ground segment components, MOC and SOC, are represented by coloured boxes. The orange arrows describe the weekly operations from reviewing and ingesting the observations requests to the uplink of the TCs. The grey arrows trace the Science and Housekeeping data flow, from raw, to stored processed data accessible to the community, as well as the orbit and pass time determination, crucial for the planning phase. Finally, the steps outlined in this paper are marked with a bold number corresponding to their respective section. astro-ph.IM

Exoplanets, -moons, -comets, Imaging & Spectroscopy, Missions & Hardware, Status Report

CHEOPS Ground Segment: Systems And Automation For Mission and Science Operations

by Keith CowingMay 15, 2025May 15, 2025

The CHEOPS, the first ESA small-class mission, has been performing photometric astronomical observations with a particular emphasis on exoplanetary science for the past five years.

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report

Updating the Ephemeris and Physical Properties of Five Long-period Transiting Exoplanets Using TESS and CHEOPS

by Keith CowingApril 3, 2025April 3, 2025

The transiting long-period exoplanets are the most interesting follow-up targets for the next-generation instruments, using the most sophisticated observational techniques.

The CHEOPS transit light curves of planet K2-266 d (top, orange) and K2-266 e (bottom, purple). For each planet, we show the corrected light curve and best-fit model (left) as well as the residuals (right). The data are plotted with respect to the linear ephemeris from Rodriguez et al. (2018). -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Stellar Cartography

Towards High Precision Mass Measurements of Two Sub-Neptunes in the K2-266 Planetary System Through Transit Timing

by Keith CowingMarch 16, 2025

Sub-Neptunes have been found to be one of the most common types of exoplanets, yet their physical parameters and properties are poorly determined and in need of further investigation.

Top: Transmission Spectroscopy showing extra absorption in the Na doublet’s core lines across different global abundances, measured in PPM. This plot compares three injected models, illustrating the presence or absence of TiO and VO. It features one example with error bars plus a main strand after several runs. In light blue, regions below 200 ppm are highlighted, indicating areas under the estimated error threshold coming from models without signals. Bottom: Three examples of Transmission Spectroscopy in PPM are presented. Black points represent data binned by a factor of 100, the light blue area denotes a 95% confidence interval, magenta highlights the core lines, and red dashed lines indicate the standard deviation of the continuum. Below these plots are normalised flux profiles centred on the core lines, with a dashed blue line marking the Na doublets. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

A Closer Look at LTT 9779b: The ESPRESSO Endeavour to Pierce the Atmospheric Veil

by Keith CowingFebruary 3, 2025February 2, 2025

The proliferation of exoplanet discoveries in exotic environments like the Neptune desert challenges our understanding of planetary atmospheres under intense irradiation. The unexpected discovery of LTT9779 b, an ultra-hot Neptune […]

TESS aperture field around the target star TOI-1803. (Image generated with tpfplotter, Aller et al. (2020)). -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

A Joint Effort To Discover And Characterize Two Resonant Mini Neptunes Around TOI-1803 With TESS, HARPS-N And CHEOPS

by Keith CowingDecember 16, 2024December 16, 2024

We present the discovery of two mini Neptunes near a 2:1 orbital resonance configuration orbiting the K0 star TOI-1803. We describe their orbital architecture in detail and suggest some possible […]

Stability analysis of the TOI-561 planetary system. For fixed initial conditions (Table 2), the parameter space of the system is explored by varying the orbital period and the eccentricity of planet- 𝑓 . The step size is 0.25 day in the orbital period and 0.0025 in the eccentricity. For each initial condition, the system is integrated over 10 000 yr, and a stability indicator is calculated, which involved a frequency analysis of the mean longitude of the inner planet. The chaotic diffusion is measured by the variation in the main frequency. Red points correspond to highly unstable orbits, while blue points correspond to orbits that are likely to be stable on Gyr timescales. The black curve corresponds to 𝐾 = 1.88 m/s and the black dot shows the values of the best fit solution (Table 2). -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Architecture Of TOI-561 Planetary System

by Keith CowingOctober 27, 2024October 27, 2024

We present new observations from CHEOPS and TESS to clarify the architecture of the planetary system hosted by the old Galactic thick disk star TOI-561.

Artist’s impression of the hotspot in WASP-76 b (Credit: Tania Cunha (Planetário do Porto - Centro Ciência Viva)/Instituto de Astrofísica e Ciências do Espaço)

Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Press Release

Instituto de Astrofísica e Ciências do Espaço Paves The Way In The Field Of Exoclimatology

by Keith CowingSeptember 6, 2024September 6, 2024

Three papers about “hot jupiter” WASP-76 b, led by Instituto de Astrofísica e Ciências do Espaço researchers, will be the foundation for understanding the global climate of a giant exoplanet.

Observed and best-fit model light-curves (one transit event) for WASP-79 b, WASP-94A b, WASP-131 b and WASP-82 b. For each observed transit, Top: the unprocessed light-curve (cyan), light-curve after wavelet denoising (magenta), the best-fit transit model (blue). Middle: the residual after modelling without GP regression (magenta), the mean (blue) and 1-σ interval (cyan) of the best-fit GP regression model. Bottom: mean residual flux (blue). The mean residual flux corresponds to the residual flux considering the mean of the best fit GP regression model. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Precise Transit Photometry Using TESS II: Revisiting 28 Additional Transiting Systems With Updated Physical Properties

by Keith CowingAugust 13, 2024August 13, 2024

Precise physical properties of the known transiting exoplanets are essential for their precise atmospheric characterization using modern and upcoming instruments. Leveraging the large volume of high SNR photometric follow-up data […]

Mean−subtracted RV data plotted in gray dotted points for each of the HARPS (top panel), ESPRESSO (middle panel), and PFS (bottom panel) instruments, along with separate model curves for the planet model (blue solid line), the GP model (green solid line) and the full planet + GP model (magenta solid line). The error bars include the jitter component 𝜎 for each instrument, which was added in quadrature to the RV error for each data point. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

TOI-757 b: An Eccentric Transiting Mini-Neptune On Aa 17.5-d Orbit

by Keith CowingAugust 12, 2024August 10, 2024

We report the spectroscopic confirmation and fundamental properties of TOI-757 b, a mini-Neptune on a 17.5-day orbit transiting a bright star (V=9.7 mag) discovered by the TESS mission. We acquired […]

CHEOPS

The Mass Of The Exo-Venus Gliese 12 b, As Revealed By HARPS-N, ESPRESSO, And CARMENES

CHEOPS Ground Segment: Systems And Automation For Mission and Science Operations

Updating the Ephemeris and Physical Properties of Five Long-period Transiting Exoplanets Using TESS and CHEOPS

Towards High Precision Mass Measurements of Two Sub-Neptunes in the K2-266 Planetary System Through Transit Timing

A Closer Look at LTT 9779b: The ESPRESSO Endeavour to Pierce the Atmospheric Veil

A Joint Effort To Discover And Characterize Two Resonant Mini Neptunes Around TOI-1803 With TESS, HARPS-N And CHEOPS

Architecture Of TOI-561 Planetary System

Instituto de Astrofísica e Ciências do Espaço Paves The Way In The Field Of Exoclimatology

Precise Transit Photometry Using TESS II: Revisiting 28 Additional Transiting Systems With Updated Physical Properties

TOI-757 b: An Eccentric Transiting Mini-Neptune On Aa 17.5-d Orbit

Roman Space Telescope: Enabling Images Of Distant Worlds

NASA Solar System Exploration Research Virtual Institute (SSERVI) Cooperative Agreement Notice (NNH26ZDA016C) Final Text And Due Dates

Interstellar Aromatic Infrared Bands: IR Absorption Spectroscopy Of The Lowest Triplet State Of Naphthalene

The Highly Unusual Behavior And Chemical Composition Of Interstellar Comet 2I/Borisov

Volatile Depletion In Rocky Planets As A Chemical Fingerprint Of Hybrid Accretion