![Radial velocity timeseries of K2-3 used in the analysis. Here the second dimension for the multi-dimensional quasi-periodic gaussian process kernes used the D2V activity indicator to disentangle the stellar activity from the Keplerian signals. The Keplerian models for all three planets are assumed to be circular orbits for this figure (Model 1 in Table C.3). The various instruments used in the analysis are colour coded. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/Uncovering.png?resize=1200%2C719&ssl=1)
[astro-ph.EP] The K2-3 system is one of the most unique planetary systems as it features three transiting sub-Neptunes in decreasing order of radii, spanning the radius valley.
HARPS-N
Posted inExoplanets, -moons, -comets
Mass Constraints For The K2-223 System Planets: An Ultra-short-period sub-Earth, A Short-period Super-Earth, And A Tentative Long-period Giant Planet
[astro-ph.EP] We present mass constraints of two short-period, terrestrial-sized planets transiting K2-223, based on high-precision radial velocity measurements from HARPS-N and ESPRESSO, as well as a tentative indication of an […]
Posted inExoplanets, -moons, -comets
Hidden Worlds: A Non-transiting Candidate Planet In The Neptunian Desert Around The Solar-type Pulsator KIC 9139163
[Astronomy & Astrophysics] Close-in substellar companions experience strong tidal and magnetic interactions with their host stars and are therefore subject to fast orbital evolution.
![Detection map of our sample (excluding system with inner giant planets). Red dots represent the known planets, including the new candidates discussed in Section 6.3. [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/The-GAPS-Programme-.png?resize=1200%2C720&ssl=1)
Posted inExoplanets, -moons, -comets
The GAPS Programme with HARPS-N at TNG LXXVII. Occurrence Rates Of Small Close-in Planets In The Presence Of Cold Jupiters
[astro-ph.EP] Context. The architecture of our Solar System, with inner small planets (ISPs) and outer giants, may or may not be common. Understanding whether a correlation exists between ISPs and […]
Posted inExoplanets, -moons, -comets
The GAPS Programme at TNG LXXIV. A Reanalysis Of The Planetary Systems TOI-1272 And TOI-1694 With HARPS-N And Retraction Of The Planetary Interpretation Of TOI-1272 c
[astro-ph.EP] Hot Neptunes are close-in exoplanets that occupy a sparsely populated region of parameter space known as the “hot-Neptune desert”.
Posted inAstronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy
A Decade Of Monitoring The HIP 41378’s Planetary System
Multi-planetary systems provide key constraints on planet formation and evolution, as their architecture encodes the dynamical history of planets formed within a common protoplanetary disk.
Posted inAstronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report
The RoPES Project With HARPS and HARPS-N III. Two Candidate Planets Orbiting The G-type Star HD 161098
Context. The development of refined instruments and techniques for a detailed analysis of the radial velocities (RVs) of stars other than the Sun allows the presence of planetary signals of […]
Posted inAstronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, TRAPPIST-1
The Multi-planet System TOI-5624: Four Transiting Sub-Neptunes With An Outer Companion Revealed By Transit-timing Variations
Following the 2022 alert of a TESS object of interest transiting TOI-5624 (a G7 V star ∼100 pc away), a CHEOPS campaign in 2023 detected four planetary signals at Pb≈3.4, […]
Posted inAstronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report
Constraining Small Planet Compositions for Future Missions
Accurate mass and radius measurements of small transiting exoplanets are essential for probing their compositions, formation histories, and potential habitability.
Posted inAtmospheres, Climate, Weather, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report
The GAPS Programme At The TNG: LXX. TOI-5734b: A Hot Sub-Neptune Orbiting A Relatively Young K Dwarf With An Earth-like Density
Increasing interest in young exoplanets is leading to a growing effort to understand the formation and evolutionary processes responsible for their different architectures. One interesting target is TOI-5734, a relatively […]