Rapidly oscillating TESS A-F main-sequence stars: are the roAp stars a distinct class?

被引:0
作者
Balona, L. A. [1 ]
机构
[1] South African Astron Observ, POB 9, ZA-7935 Cape Town, South Africa
基金
新加坡国家研究基金会;
关键词
stars: chemically peculiar; stars: oscillations; THEORETICAL INSTABILITY STRIP; LINE-PROFILE VARIATIONS; DELTA-SCUTI; PULSATION; FREQUENCY; STABILITY; MECHANISM; MODES;
D O I
10.1093/mnras/stac011
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
From sector 1-44 TESS observations, 19 new rapidly oscillating Ap (roAp) stars, 103 ostensibly non-peculiar stars with roAp-like frequencies, and 617 delta Scuti stars with independent frequencies typical of roAp stars were found. Examination of all chemically peculiar stars observed by TESS resulted in the discovery of 199 Ap stars that pulsate as delta Sct or gamma Dor variables. The fraction of pulsating Ap stars is the same as the fraction of pulsating chemically normal stars. There is no distinct separation in frequency or radial order between chemically peculiar delta Sct stars and roAp stars. In fact, all the features that originally distinguished roAp from delta Sct stars in the past have disappeared. There is no reason to assume that the high frequencies in roAp stars are driven by a different mechanism from the high frequencies in chemically normal stars. However, chemically peculiar stars are far more likely to pulsate with high frequencies. The term 'roAp' should be dropped: all roAp stars are normal delta Scuti stars.
引用
收藏
页码:5743 / 5759
页数:17
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