Ta hanyar auna yanayin yanayin taurari a cikin Milky Way za a iya kimanta shekarun taurari na farko ta hanyar auna yawan abubuwan da ke da rai na tsawon lokaci kamar thorium-232 da uranium-238, sannan a kwatanta sakamakon da kimantawar yawan su na asali, wata dabara da ake kira nucleocosmochronology. Waɗannan ƙididdigar suna samar da kimanin shekaru 12.5 ± 3 biliyan don CS 31082-001 da 13.8 ± 4 biliyan na shekaru don BD +17 ° 3248. Da zarar an kafa farin farin, sai ya fara yin sanyaya na radiation kuma yawan zafin jiki na farfajiyar ya sauka a hankali. Ta hanyar auna yanayin zafi na waɗannan ƙananan dwarfs na farin dwarfs da kuma kwatanta su da shekarun da ake tsammani, za a iya ƙayyade ƙayyadadden zafin jiki na farko. Tare da wannan ma'auni na taurari a cikin Milky Way, ana iya ƙididdige shekarun shekarun taurari na tsawon lokaci kamar thorium-232 da uranium-238, sannan a kwatanta sakamakon da ƙididdigar ƙididdigar yawan shekarun su na asali, wata da ake kira nucleocosmochronology
Shekaru biliyan 13.2