首页     开始     To Survive in the Universe    
Inhabited Sky
    News@Sky     天文图片     收集     论坛     Blog New!     常见问题     新闻     登录  

HD 69939


目录

图像

上传图像

DSS Images   Other Images


相关文章

On the dispersion in brightness of far-ultraviolet emission lines of cool giant stars
Low-resolution spectra have been obtained with the short-wavelengthcamera of IUE for late-type giant stars of spectral type F5 III-G8 III.These stars are believed to be in their first crossing of the H-Rdiagram, as inferred from their location along the blue edge of theHertzsprung gap or their high abundance of lithium. From the earliestspectral type observed along the blue edge of the gap, the normalized CIV flux, which is indicative of 100,000 K plasma, increases to a maximumat G0 and then falls with advancing spectral type. The total range inemission measure of 100,000 K gas is an order of magnitude or more amongstars making their first appearance as yellow giants and averages about25 times higher in these stars than in other G8-K0 yellow giants, themajority of which are probably He-burning post-red giants. Theobservations tentatively show that transition region emission, and byinference coronal emission, increases in intensity with the growth ofconvection zones in late-type giants and then declines at lower surfacetemperatures, perhaps because of rotational spin-down and a weakening ofdynamo action.

提交文章


相关链接

  • - 没有找到链接 -
提交链接


下列团体成员


观测天体数据

星座:長蛇座
右阿森松:08h19m25.87s
赤纬:+01°36'10.5"
视星:8.97
距离:1063.83 天文距离
右阿森松适当运动:-6.4
赤纬适当运动:-0.5
B-T magnitude:8.996
V-T magnitude:8.973

目录:
适当名称   (Edit)
HD 1989HD 69939
TYCHO-2 2000TYC 196-2272-1
USNO-A2.0USNO-A2 0900-05885790
HIPHIP 40783

→ 要求更多目录从vizier