metal-rich star Archives

Planet mass (or minimum mass) as a function of orbital period for planetary systems hosting cold Jupiters.

Exoplanets, -moons, -comets, Gas Giants, Habitable Zones, Ice Giant, Icy Worlds, Status Report, Stellar Cartography

TESS Planets In Known Radial Velocity Cold Jupiter Systems: Hot Super Earth Occurrence Is Enhanced By Cold Jupiters

by Keith CowingFebruary 14, 2026February 14, 2026

The correlation between inner super-Earths (SEs) and outer cold Jupiters (CJs) provides an important constraint on the formation and dynamical evolution of planetary systems. Previous studies have suggested a positive […]

Distribution of stellar isochrone mass (top) and spectroscopic metallicity (bottom) with isochrone (left) and gyrochronology (right) ages where the colour indicates the number of data points in each bin, with equal number of bins across the four distributions. These distributions illustrate that the two samples of isochrone and gyrochronology ages span a different parameters space in mass and metallicity despite sharing the same stars. It also shows the relationship between mass and metallicity with age which could bias the trend between occurrence rate and age. -- astro-ph.EP

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

Exoplanet Occurrence Rate with Age for FGK Stars in Kepler

by Keith CowingJanuary 24, 2025January 24, 2025

We measure exoplanet occurrence rate as a function of isochrone and gyrochronology ages using confirmed and candidate planets identified in Q1-17 DR25 Kepler data.

Super-Earth occurrence for Kepler (black circles) and K2 (gray circles), TESS data assuming all candidates are real (teal square), and 99.7% confidence intervals to calculate the upper limits for TESS data assuming all candidates are false positives (teal triangles) as a function of metallicity. The [−0.25, −0.5] bin occurrence rates are offset horizontally for visual clarity. The best-fit power-law trend line for the Kepler and K2 data (yellow) is displayed and extrapolated to [Fe/H] = −0.75 showing the 1σ uncertainties (Zink et al. 2023). We show the combined best-fit exponential trend line for Kepler, K2, and TESS (purple; Equation (6)) including the 1σ uncertainties. Each metallicity bin is indicated by gray dashed lines. Within the [−0.75, −1] bin, there is insufficient data to further constrain the super-Earth occurrence rate as a function of metallicity (denoted by the gray hatched region). -- The Astronomical Journal

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

Formation Of Super-Earths Proven To Be Limited Near Metal-poor Stars

by Keith CowingSeptember 10, 2024September 10, 2024

In a new study, astronomers report novel evidence regarding the limits of planet formation, finding that after a certain point, planets larger than Earth have difficulty forming near low-metallicity stars.

Are the observed high-density exoplanets metal-rich remnants of giant impacts? a, Super-Earths are predicted to complete their formation through giant impacts whose energies are too low to strip their rocky mantles and form metal-rich planets (Scora et al., 2020, 2022; Poon et al., 2020; Esteves et al., 2022; Goldberg and Batygin, 2022). b, After their formation ceases, super-Earths may remain on closely spaced orbits typical of observed compact systems (Weiss et al., 2022) and can experience instabilities over timescales comparable to the main-sequence lifetime of the host stars (Volk and Gladman, 2015; Pu and Wu, 2015; Tamayo et al., 2020; Volk and Malhotra, 2020). c, If a compact system becomes unstable, super-Earths may experience a second stage of giant impacts that are more energetic than those that occurred during their formation (Volk and Gladman, 2015). These late giant impacts may erode the silicate mantles of the super-Earths to form metal-rich, high-density planets. d, The final, post-instability planetary system may have a metal-rich world with density akin to the measured densities of observed high-density exoplanets (Table 1). Colors indicate different planetary compositions: orange is metal-rich, blue indicates planets with a terrestrial composition (that is, differentiated in an iron core and a rocky mantle).-- astro-ph.EP

Astrochemistry, Astrogeology, Exoplanets, -moons, -comets, Impact events, Status Report

Can Metal-rich Worlds Form By Giant Impacts?

by Keith CowingAugust 30, 2024August 29, 2024

Planets and stars are expected to be compositionally linked because they accrete from the same material reservoir. However, astronomical observations revealed the existence of exoplanets whose bulk density is far […]

Left: Average completeness map for the super-Earth RV sample with detected gas giants overplotted in teal. Right: Average completeness map for the super-Earth transit sample with detected gas giants overplotted in teal. Color scale represents detection probability. On average, the RV sample has higher completeness to distant gas giants typically driven by much longer time baselines and more data points. Accounting for differences in individual system sensitivity as well as these broad trends between transit and RV samples is key to calculating frequencies of gas giants in our sample of super-Earth systems. -- astro-ph.EP

Exoplanets, -moons, -comets, Gas Giants, Status Report, Stellar Cartography

Strong Correlation Between Inner Super-Earths And Outer Gas Giant

by Keith CowingMarch 15, 2024

The connection between outer gas giants and inner super-Earths reflects their formation and evolutionary histories. Past work exploring this link has suggested a tentative positive correlation between these two populations, […]