CHEOPS Archives

Radius-period distribution of the known young planet population. Planets are colored based on their ages, with darker purples representing the younger systems. TIC 434398831 b and c are denoted by the stars. We plot the distribution of the known exoplanet population in greyscale for reference. Both TIC 434398831 b and c lie above the mature exoplanet distribution. As they continue to evolve, both planets will likely evolve to lie in the Kepler distribution. -- astro-ph.EP

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

A Transiting Multi-planet System In The 61 Million Year Old Association Theia 116

by Keith CowingJuly 30, 2024July 30, 2024

Observing and characterizing young planetary systems can aid in unveiling the evolutionary mechanisms that sculpt the mature exoplanet population.

Detrended TESS (top row) and CHEOPS (bottom row) light curves, phase-folded to the orbital periods of HIP 29442 b (left), c (middle) and d (right). The coloured points show the 30-min binned data, the solid black lines show the best-fit transit models. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Gas Giants, Icy Worlds, Imaging & Spectroscopy, Press Release, Water/Hycean Worlds & Oceanography

Unveiling the Internal Structure And Formation History Of The Three Planets Transiting HIP 29442 (TOI-469) With CHEOPS

by Keith CowingJune 28, 2024June 28, 2024

Multiplanetary systems spanning the radius valley are ideal testing grounds for exploring the proposed explanations for the observed bimodality in the radius distribution of close-in exoplanets. One such system is […]

Mass-radius diagram for WASP-132c. The lines show the massradius relation for a pure water model (blue), an Earth-like model (green), and a pure-iron model (gray). The other exoplanets are taken from the PlanetS catalouge (Otegi et al. 2020). -- astro-ph.EP

Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Status Report

Refining the WASP-132 Multi-planetary System: Discovery of a Cold Giant Planet and Mass Measurement of a hot Super-Earth

by Keith CowingJune 27, 2024June 27, 2024

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.

Phase folded TESS transit data with modeled allesfitter fit (grey), and residuals plot on the bottom. Also plotted are the phase folded points binned to 30 minutes (black). -- astro-ph.EP

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

HD 21520 b: A Warm Sub-Neptune Transiting A Bright G Dwarf

by Keith CowingJune 17, 2024June 17, 2024

We report the discovery and validation of HD 21520 b, a transiting planet found with TESS and orbiting a bright G dwarf (V=9.2, Teff=5871±62 K, R⋆=1.04±0.02R⊙).

Evolution of the distribution of the dark current in hot pixels. The colours indicate the time when the dark M&C were taken. -- astro-ph.IM

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

CHEOPS in-flight Performance: A Comprehensive Look At The First 3.5 Years Of Operations

by Keith CowingJune 5, 2024June 5, 2024

CHEOPS is a space telescope specifically designed to monitor transiting exoplanets orbiting bright stars. In September 2023, CHEOPS completed its nominal mission and remains in excellent operational conditions. The mission […]

Stability analysis of the TOI-421 planetary system. For fixed initial conditions (Table 6), the parameter space of the system was explored by varying the orbital period Pb and the eccentricity eb of planet-b (left panel) and the eccentricities of both planets (right panel). The step size was 10−3 day in orbital period and 0.0025 in eccentricity. For each initial condition, the system was integrated over 5000 yr and a stability indicator was calculated, which involved a frequency analysis of the mean longitude of the inner planet. The chaotic diffusion was measured by the variation in the frequency (see text). Red points correspond to highly unstable orbits, while blue points correspond to orbits which are likely to be stable on a billion-years timescale. The black dots show the values of the best fit solution (Table 6). -- astro-ph.EP

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

Characterisation Of The TOI-421 Planetary System Using CHEOPS, TESS, and Archival Radial Velocity Data

by Keith CowingApril 20, 2024

The TOI-421 planetary system contains two sub-Neptune-type planets and is a prime target to study the formation and evolution of planets and their atmospheres.

Phase-folded light curves from TESS (upper panels) and CHEOPS (lower panels) measurements. The best-fit model of the transit is plotted in black for HD 15337 b (left) and HD 15337 c (right). The bottom panels for each instrument show the residuals of the best-fit model. We over-plot the binned light curves and residuals with 20-min bins. -- astro-ph.EP

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

Precise Characterisation Of HD 15337 With CHEOPS: A Laboratory For Planet Formation And Evolution

by Keith CowingMarch 26, 2024March 26, 2024

We aim to constrain the internal structure and composition of HD 15337 b and c, two short-period planets situated on opposite sides of the radius valley, using new transit photometry […]

Tracing a link between two neighbour planet at regular time interval along their orbits, creates a pattern unique to each couple. The six planets of the HD110067 system create together a mesmerising geometric pattern due to their resonance-chain. CREDIT Thibaut Roger/NCCR PlanetS

Astronomy & Telescopes, Exoplanets, -moons, -comets, Press Release, TRAPPIST-1

Six Planets Orbit HD110067 System In A Harmonic Rhythm

by Keith CowingNovember 29, 2023April 14, 2026

An international collaboration between astronomers using the CHEOPS and TESS space satellites, including NCCR PlanetS members from the University of Bern and the University of Geneva, have found a key […]

Best-fit occultation depths of individual CHEOPS visits (blue) along with their posteriors on the right. The horizontal solid and dashed lines represent the mean occultation depth of 82.4 ± 5.6 ppm. The panel on the right-side displays the best-fit posterior distribution. The green shaded regions indicate the span of the TESS Sectors 40, 41 and 54 while the brown points indicate sector-wise occultation depth. -- astro-ph.EP

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

CHEOPS Observations Of KELT-20 b/MASCARA-2 b: An Aligned Orbit And Signs Of Variability From A Reflective Dayside

by Keith CowingNovember 8, 2023November 8, 2023

Occultations are windows of opportunity to indirectly peek into the dayside atmosphere of exoplanets. High-precision transit events provide information on the spin-orbit alignment of exoplanets around fast-rotating hosts.

Results of the transit injection-and-recovery tests performed on the TESS (upper panel) and CHEOPS (lower panel) data to assess the detectability of potential additional transiting planets in the TOI-178 system. For both panels, the red stars show the locations of the 6 known planets in the system. -- astro-ph.EP

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

Refining The Properties Of The TOI-178 System With CHEOPS And TESS

by Keith CowingAugust 23, 2023August 23, 2023

The TOI-178 system consists of a nearby late K-dwarf transited by six planets in the super-Earth to mini-Neptune regime, with orbital periods between 1.9 and 20.7 days.

CHEOPS

A Transiting Multi-planet System In The 61 Million Year Old Association Theia 116

Unveiling the Internal Structure And Formation History Of The Three Planets Transiting HIP 29442 (TOI-469) With CHEOPS

Refining the WASP-132 Multi-planetary System: Discovery of a Cold Giant Planet and Mass Measurement of a hot Super-Earth

HD 21520 b: A Warm Sub-Neptune Transiting A Bright G Dwarf

CHEOPS in-flight Performance: A Comprehensive Look At The First 3.5 Years Of Operations

Characterisation Of The TOI-421 Planetary System Using CHEOPS, TESS, and Archival Radial Velocity Data

Precise Characterisation Of HD 15337 With CHEOPS: A Laboratory For Planet Formation And Evolution

Six Planets Orbit HD110067 System In A Harmonic Rhythm

CHEOPS Observations Of KELT-20 b/MASCARA-2 b: An Aligned Orbit And Signs Of Variability From A Reflective Dayside

Refining The Properties Of The TOI-178 System With CHEOPS And TESS

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