HARPS-N Archives

Time series of RV and activity indicators.

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

The RoPES Project With HARPS and HARPS-N II. A Third Planet In The Multi-planet System HD 176986

by Keith CowingJanuary 29, 2026January 29, 2026

Context. Earth-like planets orbiting in the habitable zone of K- to G-type stars create an RV effect in amplitude of less than 1 m s−1 and have orbital periods of […]

Stability analysis of the TOI-5788 planetary system. For fixed initial conditions (Table 4), the parameter space of the system is explored by varying the orbital period and the eccentricity of planet c (left panel) and the eccentricities of both planets (right panel). The step size is 0.0025 in the eccentricities, 0.001 d in the orbital period of planet b, and 0.003 d in the orbital period of planet c. For each initial condition, the system is integrated over 5000 yr and, from a frequency analysis of the mean longitude of the outer planet, a stability indicator is calculated. The colours in the plot represent the chaotic diffusion, measured by the variation in the frequency (see text). Red points correspond to highly unstable orbits, whilst blue points correspond to orbits which are likely to be stable on Gyr timescales. The black dots show the values of the best fit solution (Table 4). -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Stellar Cartography, Water/Hycean Worlds & Oceanography

Discovery and Characterisation of Two Exoplanets Orbiting the Metal-poor, Solar-type Star TOI-5788 with TESS, CHEOPS, and HARPS-N

by Keith CowingJanuary 28, 2026January 28, 2026

We present the discovery and characterisation of two transiting exoplanets orbiting the metal-poor, solar-type star TOI-5788.

VOYAGERS target stars were selected from 47,864 GES members following several screening steps. Available stellar properties were used to screen to 156 candidates. TRES spectra were then used to identify 41 candidates that would be best for a precision RV survey. Our initial survey includes 11 high priority main sequence (R/R⊙ < 2.5) and 11 more evolved (R/R⊙ < 7.5) targets. We plan to focus more observations on 10 main sequence targets for upcoming observations. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Interstellar, Status Report

Searching For Exoplanets Born Outside The Milky Way: VOYAGERS Survey Design

by Keith CowingNovember 12, 2025

Observations over the past few decades have found that planets are common around nearby stars in our Galaxy, but little is known about planets that formed outside the Milky Way.

[LEFT] GJ 536 b and c in context. The upper panel shows the masses of known planets, for masses below 100 M⊕, and periods shorter than 1000 days, with the planets of the system of GJ 536 highlighted, and the solar system planets as reference. The middle panel shows the same, but as a function of insolation. The lower panel shows the contrast in reflected light of low-mass planets orbiting bright stars (mV < 12), compared to their angular separation to their parent star. The dotted vertical lines indicate the limits in which ANDES wil be able to observe (Palle et al. 2025). The red symbols for the planets of GJ 536 show the potential range of contrasts. The green squares show the position of the ANDES golden sample. [RIGHT] Parameters of the planets of the system of GJ 536, using the adopted (circular) model. -- astro-ph.EP

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

A Second Low-mass Planet Orbiting The Nearby M-dwarf GJ 536

by Keith CowingSeptember 18, 2025September 18, 2025

GJ 536 is a low-mass star, located 10 pc away from the Sun, that hosts a low-mass planet orbiting with a period of 8.71 days.

RVs of TOI-1438. Top: The HARPS-N (blue) and HIRES (orange) RV time series with the best-fitting three Keplerian model in grey with residuals shown in the panel below. Lower: The phasefolded RV curves for planet b (left) and c (middle) as well as signal d (right). The best-fitting models are shown as the grey lines with the shaded area denoting the 1 and 2σ intervals in the K-amplitude. Residuals are given below. -- astro-ph.EP

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

TOI-1438: A Rare System With Two Short-period Sub-Neptunes And A Tentative Long-period Jupiter-like Planet Orbiting A K0V star

by Keith CowingSeptember 4, 2025September 4, 2025

We present the detection and characterisation of the TOI-1438 multi-planet system discovered by TESS.

Transit light curves and fits for HD 60779 b. The transit models were all fit simultaneously with the RVs, details listed in Table 2. The upper left panel shows the flattened 120 s cadence data from TESS Sector 34. This is the original transit detection. The lower left panel shows the flattened 20 s cadence data from TESS Sector 88. The upper right panel shows the CHEOPS light curve, with the detrending model plotted. The lower right panel shows the detrended CHEOPS transit light curve, fit with the transit model. In all panels, the black points show the data in bins of 0.025 d. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Press Release

The HD 60779 Planetary System: A Transiting Sub-Neptune On A 30-day Orbit And A More Massive Outer World

by Keith CowingAugust 28, 2025August 28, 2025

We present the discovery of the planetary system orbiting the bright (V = 7.2), nearby (35 pc), Sun-like star HD 60779, which has a mass of 1.050 +/- 0.044 solar […]

Snapshot of the triple transit of planet b, c, and d as seen by K2 at the end of 2016. This artistic representation has been created with the software tango (https://github.com/oscaribv/tango).

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

Discovery Of A Multi-planetary System Orbiting The Aged Sun-like Star HD 224018

by Keith CowingAugust 23, 2025August 23, 2025

In 2016, Kepler/K2 detected a system of two sub-Neptunes transiting the star HD 224018, one of them showing a mono-transit event.

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.

The Rossiter-McLaughlin effect of WASP-129 Ab, WASP-162b, Qatar-7b, and EPIC 219388192b. The observed data points (black) are shown with their error bars. The systemic and Keplerian orbit velocities were removed. The blue line shows the best fitting model to the data, together with 1-σ (dark grey) and 3-σ (light grey) confidence intervals. -- astro-ph.EP

Ariel Mission, Astronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Ten Aligned Orbits: Planet Migration in the Era of JWST and Ariel

by Keith CowingMay 28, 2025May 28, 2025

Understanding the diverse formation and migration pathways that shape exoplanetary systems requires characterizing both their atmospheric properties and their orbital dynamics.

The architectures of the systems with both small planets and cold Jupiters considered in this work and ordered according to increasing semi-major axis of the innermost planet (from bottom to top). The cold Jupiters in the left (27 systems) and right (23 systems) panels have masses 0.3 ≤ Mp ≤ 13 MJup and 0.5 ≤ Mp ≤ 20 MJup, respectively, with a large overlap for cold Jupiters with 0.5 ≤ Mp ≤ 13 MJup. The planet circles have sizes proportional to their mass (see legend in the top right corner), and colors depending on the orbital eccentricity (more eccentric planets are shown in yellow). The host stars are color coded as a function of stellar metallicity (metallicity increases from blue to red). -- astro-ph.EP

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

Cold Jupiters And Small Planets: A Search For Correlations With The Largest Exoplanet Samples

by Keith CowingMay 27, 2025May 27, 2025

Finding out whether there is any correlation between the presence of short-period small planets (SPs) with P≲100 d (a≲0.4 AU) and 1<Mp<20 M⊕ and that of outer cold Jupiters (CJs) […]

HARPS-N

The RoPES Project With HARPS and HARPS-N II. A Third Planet In The Multi-planet System HD 176986

Discovery and Characterisation of Two Exoplanets Orbiting the Metal-poor, Solar-type Star TOI-5788 with TESS, CHEOPS, and HARPS-N

Searching For Exoplanets Born Outside The Milky Way: VOYAGERS Survey Design

A Second Low-mass Planet Orbiting The Nearby M-dwarf GJ 536

TOI-1438: A Rare System With Two Short-period Sub-Neptunes And A Tentative Long-period Jupiter-like Planet Orbiting A K0V star

The HD 60779 Planetary System: A Transiting Sub-Neptune On A 30-day Orbit And A More Massive Outer World

Discovery Of A Multi-planetary System Orbiting The Aged Sun-like Star HD 224018

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

Ten Aligned Orbits: Planet Migration in the Era of JWST and Ariel

Cold Jupiters And Small Planets: A Search For Correlations With The Largest Exoplanet Samples

Material Cycling Across Earth’s Spheres And Triggers Of Cambrian Explosion: A Tectonic Perspective

Where Does Earth’s Nitrogen Go? Two Atoms Offer A Clue

Exotic Methanol Discovered In Planet-Building Zones

More Than One Thousand TESS Planets

First Detection Of Variable Water Clouds Outside Of Our Solar System