英语单词分类 轻松记单词

ra

异体字: Re

ra基本解释

abbr.[化]元素镭(radium)的符号

ra同义词

  • re关于
  • celestial longitude黄经
  • right ascension赤经
  • radium[化]镭(元素符号Ra)...

ra英英释义

Noun:
  • an intensely radioactive metallic element that occurs in minute amounts in uranium ores

  • ancient Egyptian sun god with the head of a hawk; a universal creator; he merged with the god Amen as Amen-Ra to become the king of the gods

  • (astronomy) the equatorial coordinate specifying the angle, measured eastward along the celestial equator, from the vernal equinox to the intersection of the hour circle that passes through an object in the sky; usually expressed in hours and minutes and seconds; used with declination to specify positions on the celestial sphere;

    "one hour of right ascension equals fifteen degrees"