Greg Gilbert
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gjgilbert.bsky.social
Greg Gilbert
@gjgilbert.bsky.social
Astronomer @Caltech
If you want all the details, you can read my paper in PNAS (www.pnas.org/doi/10.1073/...) and Sheila’s paper is on arXiv (arxiv.org/abs/2507.07169).
PNAS
Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans...
www.pnas.org
July 17, 2025 at 8:28 PM
In contrast, Sheila’s analysis of M-dwarfs does not detect this feature. The M-dwarf sample size is small (236 planets), so non-detection is not necessarily evidence of non-existence. Nevertheless, giant planets are rare around small stars, so there is reason to think the trend could be real.
July 17, 2025 at 8:28 PM
We do see one difference though. My analysis of FGK stars detected tentative (2-sigma) evidence for elevated eccentricies in the so-called exoplanet radius valley, which we hypothesize arises from giant impacts mediated by giant planets.
July 17, 2025 at 8:28 PM
The straightforward conclusion is that the astrophysics of planet formation are largely similar for cool stars (M-dwarfs) compared to more Sun-like stars (FGK dwarfs).
July 17, 2025 at 8:28 PM
Now, UF graduate student Sheila Sagear has demonstrated that the same trends hold for planets orbiting smaller M-dwarf stars.
July 17, 2025 at 8:28 PM
A conspicuous eccentricity rise at approximately 3.5 Earth-radii also coincides with known transitions in occurrence rates and host star metallicities, providing clues to formation physics.
July 17, 2025 at 8:28 PM
The eccentricity-radius relation holds for both single-transiting and multi-transiting systems, suggesting these singles and multis belong to the same parent population.
July 17, 2025 at 8:28 PM
A few months ago, I published a paper demonstrating that planets larger than Neptune have elevated orbital eccentricities compared to smaller planets. Our analysis measured eccentricities for 1646 transiting planets orbiting FGK stars, by far the largest sample of exoplanet eccentricities to-date.
July 17, 2025 at 8:28 PM
I've noticed recently that published versions of PDFs have sometimes been much larger than arXiv versions. One or two big (in terms of memory) figures can really slow down load times. Maybe something changed in LaTeX compiling?
December 16, 2024 at 5:29 PM