Anomalously Fast Core and Envelope Rotation in Red Giants
Red giants undergo dramatic and complex structural transformations as they evolve. Angular momentum is transported between the core and envelope during this epoch, a poorly understood process. Here, we infer envelope and core rotation rates from Kepler observations of ∼1517 red giants. While many me...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2025-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ade2d1 |
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| author | Siddharth Dhanpal Othman Benomar Shravan Hanasoge Jim Fuller |
| author_facet | Siddharth Dhanpal Othman Benomar Shravan Hanasoge Jim Fuller |
| author_sort | Siddharth Dhanpal |
| collection | DOAJ |
| description | Red giants undergo dramatic and complex structural transformations as they evolve. Angular momentum is transported between the core and envelope during this epoch, a poorly understood process. Here, we infer envelope and core rotation rates from Kepler observations of ∼1517 red giants. While many measurements are consistent with the existing studies, our investigation reveals systematic changes in the envelope-to-core rotation ratio and we report the discovery of anomalies such as clump stars with rapidly rotating cores and red giants with envelopes rotating faster than their cores. We propose binary interactions as a possible mechanism by which some of these cores and envelopes are spun up. These results pose challenges to current theoretical expectations and can have major implications for compact remnants born from stellar cores. |
| format | Article |
| id | doaj-art-da4154565d9d420490847860930c604e |
| institution | DOAJ |
| issn | 1538-4357 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj-art-da4154565d9d420490847860930c604e2025-08-20T02:48:19ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-01988222410.3847/1538-4357/ade2d1Anomalously Fast Core and Envelope Rotation in Red GiantsSiddharth Dhanpal0https://orcid.org/0000-0001-8699-3952Othman Benomar1https://orcid.org/0000-0001-9405-5552Shravan Hanasoge2https://orcid.org/0000-0003-2896-1471Jim Fuller3https://orcid.org/0000-0002-4544-0750Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research , Mumbai, 400005, India; Scientific Computing Department , Rutherford Appleton Laboratory, Science and Technology Facilities Council, Didcot, UKCenter for Space Science, NYUAD Institute, New York University Abu Dhabi , PO Box 129188, Abu Dhabi, UAE; Division of Solar and Plasma Astrophysics , NAOJ, Mitaka, Tokyo, JapanDepartment of Astronomy and Astrophysics, Tata Institute of Fundamental Research , Mumbai, 400005, India; Center for Space Science, NYUAD Institute, New York University Abu Dhabi , PO Box 129188, Abu Dhabi, UAETAPIR, California Institute of Technology , Pasadena, CA 91125, USARed giants undergo dramatic and complex structural transformations as they evolve. Angular momentum is transported between the core and envelope during this epoch, a poorly understood process. Here, we infer envelope and core rotation rates from Kepler observations of ∼1517 red giants. While many measurements are consistent with the existing studies, our investigation reveals systematic changes in the envelope-to-core rotation ratio and we report the discovery of anomalies such as clump stars with rapidly rotating cores and red giants with envelopes rotating faster than their cores. We propose binary interactions as a possible mechanism by which some of these cores and envelopes are spun up. These results pose challenges to current theoretical expectations and can have major implications for compact remnants born from stellar cores.https://doi.org/10.3847/1538-4357/ade2d1Red giant branchNeural networksAsteroseismologyStellar rotation |
| spellingShingle | Siddharth Dhanpal Othman Benomar Shravan Hanasoge Jim Fuller Anomalously Fast Core and Envelope Rotation in Red Giants The Astrophysical Journal Red giant branch Neural networks Asteroseismology Stellar rotation |
| title | Anomalously Fast Core and Envelope Rotation in Red Giants |
| title_full | Anomalously Fast Core and Envelope Rotation in Red Giants |
| title_fullStr | Anomalously Fast Core and Envelope Rotation in Red Giants |
| title_full_unstemmed | Anomalously Fast Core and Envelope Rotation in Red Giants |
| title_short | Anomalously Fast Core and Envelope Rotation in Red Giants |
| title_sort | anomalously fast core and envelope rotation in red giants |
| topic | Red giant branch Neural networks Asteroseismology Stellar rotation |
| url | https://doi.org/10.3847/1538-4357/ade2d1 |
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