First results of a magnetic survey of classical Cepheids
Fuente:
arXiv
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Preprint |
| Published: |
2022
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866915025181999104 |
|---|---|
| author | Barron, James A. Wade, Gregg A. Folsom, Colin P. Kochukhov, Oleg |
| author_facet | Barron, James A. Wade, Gregg A. Folsom, Colin P. Kochukhov, Oleg |
| contents | We report recent ESPaDOnS and HARPSpol spectropolarimetric observations from our ongoing magnetic survey of the brightest twenty-five classical Cepheids. Stokes $V$ magnetic signatures are detected in eight of fifteen targets observed to date. The Stokes $V$ profiles show a diversity of morphologies with weak associated longitudinal field measurements of order 1 G. Many of the Stokes $V$ profiles are difficult to interpret in the context of the normal Zeeman effect. They consist of approximately unipolar single or double lobe(s) of positive or negative circular polarization. We hypothesize that these unusual signatures are due to the Zeeman effect modified by atmospheric velocity or magnetic field gradients. In contrast, the Stokes $V$ profiles of Polaris and MY Pup appear qualitatively similar to the complex magnetic signatures of non-pulsating cool supergiants, possibly due to the low pulsation amplitudes of these two stars. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2207_09255 |
| institution | arXiv |
| publishDate | 2022 |
| record_format | arxiv |
| spellingShingle | First results of a magnetic survey of classical Cepheids Barron, James A. Wade, Gregg A. Folsom, Colin P. Kochukhov, Oleg Solar and Stellar Astrophysics We report recent ESPaDOnS and HARPSpol spectropolarimetric observations from our ongoing magnetic survey of the brightest twenty-five classical Cepheids. Stokes $V$ magnetic signatures are detected in eight of fifteen targets observed to date. The Stokes $V$ profiles show a diversity of morphologies with weak associated longitudinal field measurements of order 1 G. Many of the Stokes $V$ profiles are difficult to interpret in the context of the normal Zeeman effect. They consist of approximately unipolar single or double lobe(s) of positive or negative circular polarization. We hypothesize that these unusual signatures are due to the Zeeman effect modified by atmospheric velocity or magnetic field gradients. In contrast, the Stokes $V$ profiles of Polaris and MY Pup appear qualitatively similar to the complex magnetic signatures of non-pulsating cool supergiants, possibly due to the low pulsation amplitudes of these two stars. |
| title | First results of a magnetic survey of classical Cepheids |
| topic | Solar and Stellar Astrophysics |
| url | https://arxiv.org/abs/2207.09255 |