Alkam agejdan

Alkam agejdan di tesnallunt d azlem uddinan n yitran issiliɣ-d azal n 80% seg yitran yemgaraden deg umeɣrad, tessegraw-it-id yiwet n twenɣa ,i wakken ad t-ittessesmel s unect n yini d tedwast n usfijjej. Itran n welkem agejdan ttwassnen s akken tafasa n usfijjej-nsen d tin i d-yekkan seg tsedmirt n wezday aɣisan n uhidṛujin deg wul n yitri, dɣa anecta iga d snat n tsedmirin n wezday aɣisan i d-igellun s [[Hilyum|uhilyum].

23,000 seg telmas yemgaraden n yitran i d-yettbinen deg twenɣa-ayi. Asuneɣ yemmal-d d akken tilmas n yitran ṭṭafarent tameknut imalen deg telɣa yuzdawen seg teɣmert tazelmaṭ tafellayt (itran mellulen, izeqqlen s waṭas) ɣer teɣmert tayeffust taddayt (itran ur nzeqqel ara s waṭas), tagrawt-a tettwasemma s welkem agejdan. Akken i yella uẓuni n iwezlanen imellalen, akken i yella sufell n welkem tagrawt n yizuncafcalen (subgiants), d tegrawt n yicafcalen (giants), d yifelcafcalen (supergiants) igebren seg - s unect n yisem-is - itran meqqren s waṭas s wassaɣ ɣer tkura tanafukt. Ma d tafukt tella deg tlemmast n welkem agejdan d itri yegdan 1 n tkura tanafukt, d wazal amagdez yegdan 4,8, d umatar n yini 0.66 (B-V color index) d teẓɣelt 5.780 C d telmest n waylal G2.

Tawenɣa issegrawen ger n tkura n yitri d yini n yini waylal-is d tedwast n usfijjej-is tettwasemma s usesmel n Hertzsprung–Russell, ma d tagrawt n yitran n ubaggus-a di twenɣa-ayi tettwasemma s welkem agejdan, acku tessiliɣ-d azal n 80% seg telmas n yitran yellan deg umeɣrad. Ma d isesmilen n yitran yeffɣen seg ubaggus-a agejdan ssesmilen-d 20% seg yitran n umeɣrad, dɣa ttemsegrawen-d di twenɣa ɣef sin n yibaggusen niḍen, yerna iglamen-nsen mgaraden s waṭas ɣef yiglamen n yitran n welkem agejdan, acku asufeɣ-nsen d ufares-nsen i tfasa yettuɣal ɣer tsedmirin niḍen anagar azday aɣisan n uhidṛujin i d-igellun s uhilyum.