Work

Predicting Macroturbulence in F/G/K Dwarfs to 100 m/s Precision

Year: 2026

Type: preprint

Abstract: We leverage the high resolution and spectral stability of the Keck Planet Finder (KPF) spectrograph to investigate macroturbulence broadening via the stellar cross-correlation function (CCF). As our calibration sample, we use main sequence benchmark slow-rotators v$\sin$i < 4 km/s where rotation rates were derived from the most robust asteroseismic mode splitting measurements, independent from spectral line broadening. We fit a linear relationship for macroturbulence as a function of derived $ν_{max}$, the frequency of maximum power due to stellar oscillations, with an RMS scatter of 90 m/s. Previous studies have calibrated macroturbulence against T$_{eff}$, but we find $ν_{max}$ to be a lower dispersion predictor by a factor of 4 indicating a deeper relationship between $ν_{max}$and convective motions.

Source: arXiv (Cornell University)

DOI: 10.48550/arxiv.2609.17693

Authors: Lubin, Jack, Petigura, Erik, Masuda, Kento, Halverson, Samuel, Angelo, Isabel, Huber, Daniel, Palumbo, Michael L., III, Wang, Songhu, Wang, Xian-Yu

Institutions: University of California, Los Angeles, The University of Osaka, Jet Propulsion Laboratory, Search for Extraterrestrial Intelligence, University of Hawaiʻi at Mānoa, University of Hawaii System, Flatiron Institute, Indiana University Bloomington, Indiana University

Language: English

Topic: Stellar, planetary, and galactic studies

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: National Aeronautics and Space Administration, California Institute of Technology, Indian Council of Agricultural Research, Jet Propulsion Laboratory, Japan Society for the Promotion of Science

Awards: G1380325028, G2599221627, G2676722403, Probing the Evolution of Exoplanetary Systems Using Large-Scale Survey Data, G3648211085, G830101876

OpenAlex ID: W7213525066

Cites: 24

Cited by:

Related to: 10