A radiogenic nuclide is a nuclide that is produced by a process of radioactive decay.It may itself be radioactive (a radionuclide) or stable (a stable nuclide).. Radiogenic nuclides (more commonly referred to as radiogenic isotopes) form some of the most important tools in geology.They are used in two principal ways: In comparison with the quantity of the radioactive 'parent isotope' in …

A K-type main-sequence star, also referred to as a K-type dwarf or an orange dwarf, is a main-sequence (hydrogen-burning) star of spectral type K and luminosity class V. These stars are intermediate in size between red M-type main-sequence stars ("red dwarfs") and yellow/white G-type main-sequence stars.They have masses between 0.5 and 0.8 times the mass of the Sun …

「year」の意味・翻訳・日本語 - 年、年間、(特定の計算による) 1 年、年度、学年、…歳、年(とし)、年齢、(特に)老年、…期の学級｜Weblio英和・和英辞書