Searching for magnetic fields in pulsating A-type stars: the discovery of a strong field in the probable δ Sct star HD 340577 and a null result for the γ Dor star HR 8799

Q1 Earth and Planetary Sciences Monthly Notices of the Royal Astronomical Society: Letters Pub Date : 2023-08-16 DOI:10.1093/mnrasl/slad116

S. Hubrig, S. Jarvinen, J. Alvarado‐Gómez, I. Ilyin, M. Scholler

{"title":"Searching for magnetic fields in pulsating A-type stars: the discovery of a strong field in the probable δ Sct star HD 340577 and a null result for the γ Dor star HR 8799","authors":"S. Hubrig, S. Jarvinen, J. Alvarado‐Gómez, I. Ilyin, M. Scholler","doi":"10.1093/mnrasl/slad116","DOIUrl":null,"url":null,"abstract":"\n Numerous δ Sct and γ Dor pulsators are identified in the region of the Hertzsprung-Russell diagram that is occupied by chemically peculiar magnetic Ap stars. The connection between δ Sct and γ Dor pulsations and the magnetic field in Ap stars is however not clear: theory suggests for magnetic Ap stars some critical field strengths for pulsation mode suppression by computing the magnetic damping effect for selected p and g modes. To test these theoretical considerations, we obtained PEPSI spectropolarimetric snapshots of the typical Ap star HD 340577, for which δ Sct-like pulsations were recently detected in TESS data, and the γ Dor pulsator HR 8799, which is a remarkable system with multiple planets and two debris disks. Our measurements reveal the presence of a magnetic field with a strength of several hundred Gauss in HD 340577. The measured mean longitudinal field would be the strongest field measured so far in a δ Sct star if the pulsational character of HD 340577 is confirmed spectroscopically. No magnetic field is detected in HR 8799.","PeriodicalId":18951,"journal":{"name":"Monthly Notices of the Royal Astronomical Society: Letters","volume":"53 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2023-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Monthly Notices of the Royal Astronomical Society: Letters","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1093/mnrasl/slad116","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Earth and Planetary Sciences","Score":null,"Total":0}

引用次数: 0

Abstract

Numerous δ Sct and γ Dor pulsators are identified in the region of the Hertzsprung-Russell diagram that is occupied by chemically peculiar magnetic Ap stars. The connection between δ Sct and γ Dor pulsations and the magnetic field in Ap stars is however not clear: theory suggests for magnetic Ap stars some critical field strengths for pulsation mode suppression by computing the magnetic damping effect for selected p and g modes. To test these theoretical considerations, we obtained PEPSI spectropolarimetric snapshots of the typical Ap star HD 340577, for which δ Sct-like pulsations were recently detected in TESS data, and the γ Dor pulsator HR 8799, which is a remarkable system with multiple planets and two debris disks. Our measurements reveal the presence of a magnetic field with a strength of several hundred Gauss in HD 340577. The measured mean longitudinal field would be the strongest field measured so far in a δ Sct star if the pulsational character of HD 340577 is confirmed spectroscopically. No magnetic field is detected in HR 8799.

查看原文

微信好友朋友圈 QQ好友复制链接

本刊更多论文

在脉动a型恒星中寻找磁场:在可能的δ Sct恒星HD 340577中发现了一个强磁场，而在γ Dor恒星HR 8799中发现了一个无效结果

在赫茨普龙-罗素图中被化学上特殊的磁性Ap星占据的区域，发现了许多δ Sct和γ Dor脉冲。然而，Ap星中δ Sct和γ Dor脉动与磁场之间的联系尚不清楚:理论表明，通过计算选定的p和g模式的磁阻尼效应，磁性Ap星具有抑制脉动模式的临界场强。为了验证这些理论考虑，我们获得了典型Ap恒星HD 340577的PEPSI光谱偏振快照，其中最近在TESS数据中检测到δ Sct-like脉动，以及γ Dor脉动HR 8799，这是一个由多行星和两个碎片盘组成的非凡系统。我们的测量显示，HD 340577中存在一个强度为几百高斯的磁场。如果HD 340577的脉动特性在光谱上得到证实，那么测量到的平均纵向场将是迄今为止在δ Sct恒星中测量到的最强场。在HR 8799中没有检测到磁场。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文去求助

来源期刊

Monthly Notices of the Royal Astronomical Society: Letters Earth and Planetary Sciences-Space and Planetary Science

CiteScore

8.80

自引率

0.00%

发文量

136

期刊介绍： For papers that merit urgent publication, MNRAS Letters, the online section of Monthly Notices of the Royal Astronomical Society, publishes short, topical and significant research in all fields of astronomy. Letters should be self-contained and describe the results of an original study whose rapid publication might be expected to have a significant influence on the subsequent development of research in the associated subject area. The 5-page limit must be respected. Authors are required to state their reasons for seeking publication in the form of a Letter when submitting their manuscript.

期刊最新文献

A tight N/O–potential relation in star-forming galaxies Constraining fundamental constants with fast radio bursts: Unveiling the role of energy scale TeV afterglow from GRB 221009A: photohadronic origin? Emirical calibration for helium abundance determinations in active galactic nuclei One-sided Hα excess before the first pericentre passage in galaxy Pairs