SAZI KASIPHO MAJOLA
NGELEDLULE sikhulume ngesimonkanyezi ( star system) selanga okuyilapho siphila khona. Namuhla sizothi halamuzi ngomakhonya walesi simonkanyezi, okuyilona uqobo ilanga.
Ilanga leli liyinkanyezi etholakala enkabeni yesimonkanyezi salo. Liyindilinga eyakhiwe ngokusagqinsi, okusaluketshezi namagesi ahlukene. Liwumnyombo wempilo emhlabeni.
Usuku lokuqala esontweni ngesiNgisi, uSunday, luqanjwe ngale nkanyezi ( Sun’s day — okuyigama elilinganiselwa eminyakeni engama-700 ubudala. AmaNgisi aliboleke kwisiLatin, okuwu- dies solis (okusho usuku lwelanga).
UBULONA
Ilanga liyingxenye yezinkanyezi ezibizwa nge- G-type main-sequence stars - okuyizinkanyezi ezibuye zaziwe ngezinkanyezi-mbumbulu eziphuzi ( yellow dwarf star). Empeleni le nkanyezi yethu iyimibala eyahlukene ehlangene ndawonye kodwa uma ibukwa, ibonakala imhlophe.
Le mibala eyahlukene yelanga ibonakala kahle othingweni lwenkosanazana ( rainbow). Ilanga yilona elinesisindo esikhulu kulesi simonkanyezi njengoba linesingama-99.86%, liyisi- +4.83 Absolute magnitude [okuyindlela yokukala ukukhanya kwezakhiwomkhathi ( celestial objects), okwenza likhanye kakhulu kunezinyankezi ezingama-85% ezikumaxhobela ( galaxy), uMilky Way, kwazise iningi lazo liyizinkanyezi-mbumbulu ezibomvu.
Kucatshangelwa ukuthi ilanga, elisemphakathini wokuqala wezinkanyezi ( Population I Stars) lakhiwe wukushintsha isigubhukane kwamandla omoya odalwe wukuqhuma kwenkanyezikazi noma izinkanyezikazi ezevile kweyodwa ( supernovae).
Okwenza kucatshangelwe kulokhu, wukuthi esimeninkanyezi selanga ziyinsada izinsimbi eziyigugu okubalwa kuzona igolide neuranium uma kuqhathaniswa nasezinkanyezini ezisemphakathini wesibili ( Population II) - ezinembijana yokusansimbi.
Ilanga yisona sakhiwomkhathi esikhanya kunazo zonke ezisesibhakabhakeni uma ubuka use- mhlabeni, lingama- -26.76 apparent magnitude (m) (okuyindlela yokukala ukukhanya uma kubonwa ngumuntu osemhlabeni).
Lokhu kukhanya kungaphindaphindwa kayizi-13 billion apparent magnitude uma kuqhathaniswa nokukaSirius - okuyikanyezi elandelayo ngokugqama esibhakabhakeni sethu, uma siyibheke sisemhlabeni - okwakhe kuwu- -1.46 apparent magnitude.
Ukusuka enkabeni yelanga uya kweyomhlaba, wu-1 Astronomical Unit (AU) okuyizi-150 000 000 km - yize leli banga liye lishintshashintshe ngenxa yokuthi umhlaba kawushayi umzungezo ( orbit) endaweni eyodwa.
NgoMasingana (January) usuke uzungenza eduze nelanga ( perihelion) kanti ngoNtulikazi (July) usuke uqhelile kulona ( aphelion). Ukukhanya kuthatha imizuzu eyisi-8 nemizuzwana eli-19 ukusuka elangeni kuya emhlabeni kanti uma umhlaba nelanga kusondelene, ukukhanya kufinyeza isikhathi ngemizuzwana emibili.
Ukukhanya kwelanga - njengoba sesishilo - kuyisisekelo sempilo emhlabeni futhi yikhona okuholela ekuguquguqukeni kwesimo sezulu. Ilanga kalinawo umngcele - lapho ligcina khona - ngqo, kodwa ukubumbana kwalo ( density) kuncipha ngokushesha lapho kuqala khona izikocwazi-ndilinga ( photosphere) (lapho kuqala khona ukubonakala kokukhanya kwalo okuthanda ukushuba).
Uma-ke likalwa, ingxenye-mugqankaba ( radius), ibalwa kusuka enkabeni yelanga kuya ekugcineni kwezikocwazi-ndilinga - okuyiyona ndawo ebonakalayo yobusomhlaba ( surface) belanga.
IZAKHIWO ZAMAKHEMIKHALI EZISELANGENI
Ilanga liqukethe kakhulu i- hydrogen (74.9% ne- helium (23.9%) ethanjeni ( core) nakwizikocwazi-ndilinga. Zonke izinto ezichazwa njengokusansimbi okuyigugu kwezezinkanyezi, zingaphansi kwe-2% kanti umoyampilo ( oxygen) ungaphansi kwe-1%, umoyasikhutha ( carbon) uyi-0.3%, i- neon iyi-0.2%, insimbi ( iron) iyi-0.2%.
IZINGXENYE ZALO Ithambo lelanga lilinganiselwa ema-20-25% ukusuka enkabeni uhamba ngengxenye-mugqankaba. Ukushuba kwalo ithambo leli, kuwu-150 g/cm3 - okuwukushuba okuphindwe kali-150 uma kuqhathaniswa namanzi - ukushisa kwalo kulinganiselwa ezi-15.7 million kelvins sius).
Noma-ke ithambo lishisa ngale ndlela kodwa ebuswenimhlaba belanga ukushisa kulinganiselwa ezi5800 K (4726,85 degrees celsius). Ucwaningo lwakamuva olwenziwe yiSolar and Heliospheric Observatory (SOHO), luveza ukuthi ilanga lizungeza ngesivinini esiphezulu ethanjeni kunasenyameni ( radiative zone - okuyindawo esuka onqenqemeni lwethambo iya esikhunjeni ( convetive zone). (K) (15699726,85 degrees cel- Ukushisa kuyehla enyameni yelanga cishe kusuka ezi-7-2 million K (6999726,85 - 1999726,85 degrees celsius) uma ngasemngceleni wenyama nesikhumba kanti nokushuba kwelanga kuyahlelembeka kusuka ema-20g/cm3 kuya e-0.2g/cm3 - ukusuka e-0.25-0.7% lengxenye-mugqankaba.
Inyama nesikhumba kuhlukaniswe yisiyingana esibizwa nge- tachocline. Isikhumba selanga sisuka e-0.7% (200 000 km) kuya ebuswenimhlaba. Yingxenye yelanga okuyiyona ebonakalayo uma usemhlabeni kodwa eyenza ukuba ungakwazi ukubona ethanjeni lalo.
NGAMAFUPHI * Ibanga ukusuka emhlabeni uya elangeni: 1 Astronomical Unit (AU) 150 000 000 000km
* Ukukhanya kwalo uma kukalwa ngumuntu osemhlabeni: -26.74 apparent magnitude.
* Ukukhanya uma kubonwa ngumuntu esemhlabeni: 4.83 Absolute magnitude.
* Lingaphansi kwaliphi iqoqo lezinkanyezi: G main sequence Stars.
* Okungeyona i- hydrogen ne- helium elangeni: kuwu-0.0122Z.
* Ibanga ukusuka ethanjeni likamaxhobela ( galaxy), uMilky Way kuya lapho likhona: 2.7e+13 (okuyinto elingana no-1 000 000 000 000 x 1 000 000 000 000 x 2.7)
* Isikhathi elisithathayo lizungeza inkaba kaMilky Way: silinganiselwa ezi-2 500 000 000 year.
* Isivinini salo uma lizungeza: 220 km/s.
* Ukusuka enkabeni uya onqenqemeni: yizi-695 700km (okwenza umugqankaba ( diameter) ube yizi1.3 million).
Ubukhulu balo: ungahlanganisa imihlaba eli-109 ( 43790000 km).
Ubudala balo: 4.6 billion years
UKWAKHEKA KWEZIKOCWAZI-NDILINGA Hydrogen 73.46% Helium: 24.85% Oxygen: 0.77% Carbon: 0.29% Iron: 0.16% Neon: 0.12% Nitrogen: 0.09% Silicon: 0.07% Magnesium: 0.05% Sulphur: 0.04%