The "Other" Centuries-Long Record of Solar Magnetic Activity Cycles: Lessons From the Stars
Abstract
Studies of space climate and solar magnetic activity and studies of stellar dynamos and magnetic cycles are separated by discipline and by the quality of the data we have to work with: the Sun gives us detailed knowledge of a single star, while the stars give us comparatively sparse data across a range of (sometimes poorly known) masses and ages. This review, a collaboration among scientists with expertise in stellar astronomy, space climate, and solar physics, seeks to provide a guide to what the Sun's and stars' magnetic activity records can tell us about how stellar dynamos operate on decadal, millennial, and stellar-evolutionary timescales. It reviews the historical Solar sunspot record, terrestrial cosmogenic isotope records, and decades-long chromospheric activity measurements of dozens of sun-like stars across a range of masses, ages, and metallicities near the solar value. Particular emphasis is placed on the Maunder minimum, and the hunt for similar events in the stellar record, especially the recently discovered grand minimum event ongoing in the star HD 166620. These records show that solar-like dynamos are a common feature of Sun-like stars, and magnetic grand minimum events akin to the Maunder minimum might be very rare, with only one identified in 3,000 star-years of magnetic activity records. Together, solar and stellar dynamo studies are bringing a still-fuzzy picture into focus in which stellar magnetic activity weakens as stars spin down over billions of years towards a critical Rossby number near the solar value, at which point stellar cycles begin to be frustrated. These periods of frustration manifest as magnetic grand minima, and increase in frequency until they become permanent and stars enter a period of very low and constant magnetic activity.
Related
- Activity Cycles in Solar-Type Stars
- Large-Scale Latitude-time Relationships Between the Green-Line Corona and Sunspot Activity During Solar Cycles 18-24
- Reconstruction of pretelescopic and early telescopic solar activity cycles from auroral records
- Cross-layer coupling in active-region upflows: Statistical connections between photospheric magnetic field, chromospheric activity, and coronal blueshifts
- Stellar Parameters and Magnetic Activity of Eruptive Variable Stars Based on TESS Light Curves and the LAMOST Spectral Survey
BibTeX
@misc{wright2026other,
title = {{The "Other" Centuries-Long Record of Solar Magnetic Activity Cycles: Lessons From the Stars}},
author = {Jason T. Wright and Travis S. Metcalfe and Kristof Petrovay and Hisashi Hayakawa},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.22473},
eprint = {2609.22473},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.22473},
}
RIS
TY - UNPB
TI - The "Other" Centuries-Long Record of Solar Magnetic Activity Cycles: Lessons From the Stars
AU - Jason T. Wright
AU - Travis S. Metcalfe
AU - Kristof Petrovay
AU - Hisashi Hayakawa
PY - 2026
DA - 2026/09/18
PB - arXiv
DO - 10.48550/arxiv.2609.22473
UR - https://arxiv.org/abs/2609.22473
AB - Studies of space climate and solar magnetic activity and studies of stellar dynamos and magnetic cycles are separated by discipline and by the quality of the data we have to work with: the Sun gives us detailed knowledge of a single star, while the stars give us comparatively sparse data across a range of (sometimes poorly known) masses and ages. This review, a collaboration among scientists with expertise in stellar astronomy, space climate, and solar physics, seeks to provide a guide to what the Sun's and stars' magnetic activity records can tell us about how stellar dynamos operate on decadal, millennial, and stellar-evolutionary timescales. It reviews the historical Solar sunspot record, terrestrial cosmogenic isotope records, and decades-long chromospheric activity measurements of dozens of sun-like stars across a range of masses, ages, and metallicities near the solar value. Particular emphasis is placed on the Maunder minimum, and the hunt for similar events in the stellar record, especially the recently discovered grand minimum event ongoing in the star HD 166620. These records show that solar-like dynamos are a common feature of Sun-like stars, and magnetic grand minimum events akin to the Maunder minimum might be very rare, with only one identified in 3,000 star-years of magnetic activity records. Together, solar and stellar dynamo studies are bringing a still-fuzzy picture into focus in which stellar magnetic activity weakens as stars spin down over billions of years towards a critical Rossby number near the solar value, at which point stellar cycles begin to be frustrated. These periods of frustration manifest as magnetic grand minima, and increase in frequency until they become permanent and stars enter a period of very low and constant magnetic activity.
ER -