INVESTIGATION OF MICROFLARING AND SECULAR AND QUASI-PERIODIC VARIATIONS IN DME FLARE STARS .7. A REVIVED PLANETESIMAL-IMPACT HYPOTHESIS AND THE YOUNG DM0.5E-STAR, GLIESE-182

被引:0
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作者
ANDREWS, AD
机构
关键词
STELLAR ATMOSPHERES; DME FLARE STARS; SURFACE ACTIVITY; STELLAR PHOTOMETRY; ASTEROIDS; PLANETESIMALS;
D O I
暂无
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
A schematic connection is made between stellar flares and planetesimal penetration and subsequent explosion within young dMe stars in an "impact" hypothesis. We suggest that impacts may modify the velocity spectrum in the convective motions at the footpoints of closed coronal loops, and also may induce the triggering of the flare mechanism in young dMe stars. Some relevant results from continuous photoelectric monitoring in 1981 of the young, dM0-1e flare star, Gliese 182 (= V 1005 Ori), a possible candidate to possess a planetesimal system, are presented. Using Fourier analysis techniques, we find that the U-band light curve over 1.6h may be accurately represented by frequency components from near zero to 16.7 mHz (down to period of 1 min). Negligible power exists beyond this upper frequency limit. This monitoring interval includes a very large flare (1981, Oct. 2 at 01:35:34 UT) and extensive pre-flare and post-flare, quiescent data. Moreover, at maximum light, a fragment of a sinusoidal variation, with period 59 s and amplitude 5%, was noted lasting 2.5 min. A time signature of 59 s is discussed in the context of Ionson-Mullan resonating coronal loop model and the planetesimal scenario.
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页码:219 / 231
页数:13
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