Stars like the Sun host dynamo-driven magnetic fields that heat the stellar atmosphere to millions of degrees and drive quasi-steady stellar winds. Due to the loss of angular momentum in these magnetized stellar winds, stars between 0.2 and 1.5 solar masses efficiently spin-down during the main sequence which effectively links rotation (and magnetic activity) to stellar age. Gyrochronology takes advantage of this in order to estimate stellar ages from rotation period observations. This technique will be used in the upcoming PLATO mission along with other techniques such as asteroseismology. However, the wealth of rotation period observations from the Kepler/K2 mission and the asteroseismic rotation periods of older Sun-like stars have highlighted several features that are missing from current theories of rotation period evolution.
Rotation evolution models can now account for the exchange of angular momentum between a young star and its disk, exchanges between the radiative core and convective envelope, and the loss of angular momentum in the stellar wind. However, only a few models attempt to explain the epoch of stalling observed around 0.6 to 1 billion into the main sequence lifetime of a Sun-like star (the intermediate-rotation gap) and the weakened magnetic braking needed to explain the rotation of Sun-like stars older than the Sun. The physical mechanism(s) behind these epochs of stalling currently lack a strong theoretical basis, and limit the accuracy of stellar ages from gyrochronology. Advances in modelling stellar winds, measuring magnetic fields through spectro-polarimetry, and recovering stellar structure and rotation from asteroseismology, are allowing the community to examine these epochs of stalling in greater detail. Given the Sun’s positioning with respect the weaking of magnetic braking, the increased interest in coronal and solar wind physics due to Parker Solar Probe and Solar Orbiter may allow us to determine if the Sun is in a state of transition or not.
ESA’s upcoming PLAnetary Transits and Oscillations of stars (PLATO) mission will significantly increase the number of rotation period measurements and asteroseismic detections. However, the ambiguity surrounding the epochs of apparent stalling in the rotation evolution of Sun-like stars will limit the reliability of stellar ages from gyrochronology. Therefore, leading up to the launch of PLATO in 2026, the community must seek to better understand the physical processes at play during these epochs. This research topic aims to explore the mechanisms that may be responsible for the observed gaps or epochs of stalling in the rotation evolution of Sun-like stars.
We welcome:
(a) Reviews and mini-reviews on topics such as; modelling the angular momentum-loss rates of Sun-like stars; accounting for the stalling of rotation in gyrochronology and magneto-gyrochronology; calibrating photometric and asteroseismic rotation periods; contextualizing the upcoming ESA PLATO mission.
(b) Original research from observations of solar/stellar magnetism to models of solar/stellar coronae, winds, and rotation-evolution.
(c) Hypothesis and Theory that meet the challenges posed by the current observational constraints.
Keywords:
solar-like stars, gyrochronology, stellar magnetic field, PLATO, Kepler, asteroseismology, stellar rotation
Important Note:
All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.
Stars like the Sun host dynamo-driven magnetic fields that heat the stellar atmosphere to millions of degrees and drive quasi-steady stellar winds. Due to the loss of angular momentum in these magnetized stellar winds, stars between 0.2 and 1.5 solar masses efficiently spin-down during the main sequence which effectively links rotation (and magnetic activity) to stellar age. Gyrochronology takes advantage of this in order to estimate stellar ages from rotation period observations. This technique will be used in the upcoming PLATO mission along with other techniques such as asteroseismology. However, the wealth of rotation period observations from the Kepler/K2 mission and the asteroseismic rotation periods of older Sun-like stars have highlighted several features that are missing from current theories of rotation period evolution.
Rotation evolution models can now account for the exchange of angular momentum between a young star and its disk, exchanges between the radiative core and convective envelope, and the loss of angular momentum in the stellar wind. However, only a few models attempt to explain the epoch of stalling observed around 0.6 to 1 billion into the main sequence lifetime of a Sun-like star (the intermediate-rotation gap) and the weakened magnetic braking needed to explain the rotation of Sun-like stars older than the Sun. The physical mechanism(s) behind these epochs of stalling currently lack a strong theoretical basis, and limit the accuracy of stellar ages from gyrochronology. Advances in modelling stellar winds, measuring magnetic fields through spectro-polarimetry, and recovering stellar structure and rotation from asteroseismology, are allowing the community to examine these epochs of stalling in greater detail. Given the Sun’s positioning with respect the weaking of magnetic braking, the increased interest in coronal and solar wind physics due to Parker Solar Probe and Solar Orbiter may allow us to determine if the Sun is in a state of transition or not.
ESA’s upcoming PLAnetary Transits and Oscillations of stars (PLATO) mission will significantly increase the number of rotation period measurements and asteroseismic detections. However, the ambiguity surrounding the epochs of apparent stalling in the rotation evolution of Sun-like stars will limit the reliability of stellar ages from gyrochronology. Therefore, leading up to the launch of PLATO in 2026, the community must seek to better understand the physical processes at play during these epochs. This research topic aims to explore the mechanisms that may be responsible for the observed gaps or epochs of stalling in the rotation evolution of Sun-like stars.
We welcome:
(a) Reviews and mini-reviews on topics such as; modelling the angular momentum-loss rates of Sun-like stars; accounting for the stalling of rotation in gyrochronology and magneto-gyrochronology; calibrating photometric and asteroseismic rotation periods; contextualizing the upcoming ESA PLATO mission.
(b) Original research from observations of solar/stellar magnetism to models of solar/stellar coronae, winds, and rotation-evolution.
(c) Hypothesis and Theory that meet the challenges posed by the current observational constraints.
Keywords:
solar-like stars, gyrochronology, stellar magnetic field, PLATO, Kepler, asteroseismology, stellar rotation
Important Note:
All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.