VARIABILITY OF EMISSION-LINES IN THE PLANETARY-NEBULAE IC-4997 AND NGC-6572

被引：31

作者：

FEIBELMAN, WA ^{[1
]}

ALLER, LH ^{[1
]}

HYUNG, S ^{[1
]}

机构：

[1] UNIV CALIF LOS ANGELES,DEPT ASTRON,LOS ANGELES,CA 90024

来源：

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC | 1992年 / 104卷 / 675期

关键词：

D O I：

10.1086/133003

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We compare new IUE high-dispersion data and recent ground-based spectra of the planetary nebulae IC 4997 and NGC 6572 with equivalent IUE observations taken in 1980 and optical data taken in 1974-1990. Significant changes are detected in many emission-line fluxes in IC 4997, and primarily in He II and C IV for NGC 6572. We interpret these changes as due to recent temperature increases in the central stars of the planetaries which are known to belong to a small set which have shown variability in the past.

引用

页码：339 / 349

页数：11

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