Seismic constraints on the spin evolution of slowly rotating young intermediate-mass stars
Fuente:
arXiv
Gespeichert in:
| Hauptverfasser: | , , , |
|---|---|
| Format: | Preprint |
| Veröffentlicht: |
2025
|
| Schlagworte: | |
| Online-Zugang: | |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| _version_ | 1866915272239087616 |
|---|---|
| author | Singh, K. H. Panda, S. K. Hanasoge, S. M. Dhanpal, S. |
| author_facet | Singh, K. H. Panda, S. K. Hanasoge, S. M. Dhanpal, S. |
| contents | $δ$ Scuti stars are hot, rapid rotators and are a poorly understood class of pulsators. Asteroseismology provides the only means with which to probe their interior dynamics. However, their complex and unexplained oscillation patterns restrict analyses to only a small fraction with interpretable pulsations. Here, we identify 5381 $δ$ Scuti stars from 63 sectors of TESS observations, of which 300 had interpretable oscillations, with 24 showing rotational splittings. We inferred compositions and ages ($τ$) for the 300 stars finding them in near-ZAMS states (Bedding et al. 2020), and measured the mean envelope rotation rates ($< f_{rot} >$) for 24 of them. Analyzing their age-dependent rotation, we found these stars essentially exhibit weak-to-no spindown, while evolving past the ZAMS across a narrow time-span during which they show regular pulsations. A quantitative fit to their spin-evolution results in a trend $f_{rot} (d^{-1}) \propto (τ/{Gyr})^{-0.048 \pm 0.016}$, much slower than the spindown of cooler late-type stars due to magnetic braking (Skumanich's law: $f_{rot} (d^{-1}) \propto (τ/{Gyr})^{-0.5}$). Based on stellar evolution calculations, we show this weak spindown is consistent with the gradual increase in their moment-of-inertia. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2504_08229 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Seismic constraints on the spin evolution of slowly rotating young intermediate-mass stars Singh, K. H. Panda, S. K. Hanasoge, S. M. Dhanpal, S. Solar and Stellar Astrophysics $δ$ Scuti stars are hot, rapid rotators and are a poorly understood class of pulsators. Asteroseismology provides the only means with which to probe their interior dynamics. However, their complex and unexplained oscillation patterns restrict analyses to only a small fraction with interpretable pulsations. Here, we identify 5381 $δ$ Scuti stars from 63 sectors of TESS observations, of which 300 had interpretable oscillations, with 24 showing rotational splittings. We inferred compositions and ages ($τ$) for the 300 stars finding them in near-ZAMS states (Bedding et al. 2020), and measured the mean envelope rotation rates ($< f_{rot} >$) for 24 of them. Analyzing their age-dependent rotation, we found these stars essentially exhibit weak-to-no spindown, while evolving past the ZAMS across a narrow time-span during which they show regular pulsations. A quantitative fit to their spin-evolution results in a trend $f_{rot} (d^{-1}) \propto (τ/{Gyr})^{-0.048 \pm 0.016}$, much slower than the spindown of cooler late-type stars due to magnetic braking (Skumanich's law: $f_{rot} (d^{-1}) \propto (τ/{Gyr})^{-0.5}$). Based on stellar evolution calculations, we show this weak spindown is consistent with the gradual increase in their moment-of-inertia. |
| title | Seismic constraints on the spin evolution of slowly rotating young intermediate-mass stars |
| topic | Solar and Stellar Astrophysics |
| url | https://arxiv.org/abs/2504.08229 |