He aha te tikanga o te pūtaiao whetū karihi?
Ko te ahupūngao whetū karihi he peka o te pūtaiao e ako ana i ngā tukanga karihi e puta ana i te ao whānui me te āhua o tā rātou hanga, te whakarerekē, me te tohatoha i ngā mea o te ao tūroa. Ahakoa e pā ana te ahupūngao whetū ki ngā mea o te rangi—pērā i ngā whetū, ngā aorangi, ngā nebulae, me ngā tupua whetu—e whakaatu ana te ahupūngao whetū i ngā "mīhini" e mahi ana i roto i a rātou: ngā tauhohenga karihi, te pirau irahiko, me ngā taunekeneke matūriki kaha-teitei e whakatau ana i te whanaketanga o ngā whetū me te takenga mai o ngā huānga matū.
I roto i te oranga o ia rā, e mōhio ana tātou ko te karihi ngota te pokapū o te ngota, he mea tito mai i ngā porotona me ngā neutron. I te wāhi mokowhiti, kāore ēnei karihi e noho noa iho i reira; ka tauhohe rātou i roto i ngā taiao tino pāmahana me te pēhanga. Hei tauira, i te pokapū o te whetu, ka eke te pāmahana ki te miriona ki te piriona nekehanga. Mā ēnei āhuatanga ka taea e ngā karihi ngota te tukinga me te whakakotahi i ngā karihi mama ki ngā karihi taumaha, me te tuku i te pūngao. Ko tēnei pūngao te mea e tiaho ai ngā whetu, ā, koia te "wheketere" matua mō te hanganga o ngā huānga i roto i te ao whānui.
He aha te hiranga o te ahupūngao whetū karihi?
Ka arohia e te ahupūngao whetū ngā pātai pūtaiao nui. Tuatahi: nō hea mai ngā huānga matū? Kāore ngā huānga pēnei i te waro i roto i ō tātou tinana, te hāora e manawahia ana e tātou, tae noa ki te koura i roto i ngā whakapaipai e puta noa mai ana i te hau angiangi. Ka hangaia ēnei mā roto i tētahi raupapa o ngā tauhohenga karihi i roto i ngā whetū me ngā huihuinga ao tino nui, kātahi ka horapa ki te wāhi i waenga i ngā whetū mā roto i ngā hau whetū, i ngā pahūtanga supernova rānei. Tuarua: me pēhea te ora me te mate o ngā whetū? Ko te huringa ora o te whetū ka whakatauhia nuitia e te "wahie" karihi e wātea ana i roto i tōna pūtake me ngā tauhohenga e kaha ana i tētahi wāhanga. Tuatoru: me pēhea tātou e whakamātautau ai i ngā ture o te ahupūngao i raro i ngā āhuatanga tino nui? He tino tiketike ngā āhuatanga pēnei i ngā whetū neutron, ka waiho hei taiwhanga taiao mō te whakamātautau i ngā ariā o te matū i ngā tino nui.
Ngā ariā taketake: te hanumi, te pirau, me te hopu matūriki
E tīmata ana te ahupūngao whetū karihi i ngā tukanga matua e toru.
1. Te hanumitanga karihi: te hanumitanga o ngā karihi māmā ki ngā karihi taumaha. Ko te tauira tino rongonui ko te hurihanga o te hauwai ki te hēriuma i roto i ngā whetū pērā i te Rā. Ka tukuna te pūngao e te hanumitanga nā te mea he iti ake te papatipu katoa o ngā hua i te papatipu o ngā matū tauhohe; ka hurihia tēnei rerekētanga papatipu hei pūngao e ai ki te whārite \(E = mc^2\).
2. Te pirau irahiko: ka huri ngā karihi kore pumau hei karihi kē atu mā te tuku i ngā matūriki, i te irahiko rānei. He mea nui tēnei pirau i roto i ngā horopaki maha, pērā i te noho hei pūtake wera ā-roto i roto i ētahi mea o te rangi, me te noho hei "karaka" ao whānui hei whakatau i te pakeketanga.
3. Te hopu i ngā matūriki: hei tauira, te hopu i ngā niutorone, i ngā porotona rānei e te karihi. He mea nui tēnei tukanga ki te hanganga o ngā huānga taumaha, inā koa he nui ngā niutorone, ā, he poto noa te wā e wātea ana.
Ka puta ēnei tukanga e toru i ngā tere e pāngia ana e te pāmahana, te mātotoru, te hanganga rauemi, me te tūponotanga o te tauhohenga. Koinei te wāhi e tino hira ai ngā raraunga ahupūngao karihi—pērā i ngā wāhanga whakawhiti tauhohenga me ngā haurua-ora.
Te ahupūngao whetū karihi i roto i ngā whetū: mai i te "tahu" hauwai ki te rino
Ka whiwhi ngā whetū i te pūngao mai i tētahi tauhohenga mekameka o ngā tauhohenga karihi e kiia nei ko te wāhanga "tahu", ahakoa he rerekē i te tahunga matū. Ko te raupapa o ēnei wāhanga e whakawhirinaki ana ki te papatipu o te whetū.
– Te tahunga hauwai: I roto i ngā whetū pērā i te Rā, ka hanumi te hauwai hei hanga i te heriuma mā te mekameka porotona-porotona. I roto i ngā whetū nui ake, wera ake, ko te huringa CNO (waro-hauota-hāora) te mea matua; ko ngā huānga C, N, me O hei whakakorikori.
– Te tahunga o te heriuma: I te mimiti haere o te hauwai i roto i te pūtake, ka mimiti te pūtake, ka wera, ka taea ai te hanumi o te heriuma mā te tukanga triple-alpha hei hanga waro. Mai i tēnei, ka taea hoki te hanga i ngā huānga pēnei i te hāora.
– Ngā wāhanga matatau i roto i ngā whetū nunui: Ka taea e ngā whetū nunui te whakakotahi tonu i ngā huānga taumaha: te waro, te neon, te hāora, tae atu ki te silicon. Ka puta ake i ēnei wāhanga ngā matua taumaha ake, ā, ka tata ki te rino.
He aha i kiia ai te rino ko te rohe? Nā te mea kāore te hanumitanga o ngā karihi taumaha atu i te rino e tuku i te pūngao, engari me tuku. Nō reira, ina kī tonu te uho o tētahi whetu nui i ngā huānga rite ki te rino, ka mutu te whai hua o te "mīhini" pūngao hanumi. I tēnei wā, kei te tata te whetu nui ki te hinganga o te kaha ā-papa, ka arahi pea ki tētahi supernova.
Ngā supernova me te whānautanga o ngā huānga taumaha
He huihuinga nui ngā supernova i roto i te ahupūngao whetū karihi. Ina hinga te pūtake o tētahi whetu nui, ka puta he pahūtanga nui. I raro i ēnei āhuatanga tino kino, ka puta he rerenga niutron kaha, ka taea ai te hanga i ngā huānga taumaha atu i te rino mā te hopu niutron.
I te nuinga o te wā, e rua ngā tikanga mō te hanganga o ngā huānga taumaha:
– Te tukanga-s (te hopu pōturi i te niutron): ka pōturi ake te hopu i te niutron i te pirau beta. Ko te tikanga ka puta tēnei tukanga i roto i ngā whetū nunui whero (hei tauira, ngā whetū i te wāhanga AGB) ā, ka puta mai ētahi huānga pēnei i te strontium, te barium, me te mata.
– Te tukanga-r (te hopu tere i te niutron): ka tere ake te hopu i te niutron i te pirau beta. Me whai taiao tino nui te niutron i tēnei tukanga. Haunga ngā supernovae, kua mōhiotia inaianei ko ngā hanumitanga o ngā whetu niutron tētahi o ngā pūtake nui o te tukanga-r, e whakaputa ana i ngā huānga pēnei i te koura, te konukawata, me ētahi atu huānga taumaha.
Ko te kitenga o ngā ngaru ā-papa mai i ngā hanumitanga o ngā whetu niutron me te mātakitaki i ngā kilonovae e whakakaha ana i te whakaaro ka taea te "whakaputa" i ngā huānga taumaha i roto i ēnei huihuinga. E whakaatu ana tēnei i te hononga o te ahupūngao whetū karihi ki te ariā, te mātakitaki, me te whakamātautau ki roto i tētahi kōrero ao kotahi.
Te tūranga o ngā whetū niutron, ngā hihi o te ao, me ngā niutrino
Haunga ngā whetū noa, he kaupapa nui anō hoki ngā mea tino nui pērā i ngā whetū niutron. He toenga supernova tino matotoru ngā whetū niutron; ka taea e te tīpune o ā rātou rauemi te taumaha i ngā piriona tāne. I reira, ko ngā taunekeneke karihi e uru ana ki ngā āhua o te rauemi i ngā kiato uaua ki te tārua i roto i te taiwhanga. Ka akohia hoki e te ahupūngao whetū karihi ngā tauhohenga i roto i te kiri o ngā whetū niutron, pērā i ngā mea e puta ana ina taka ngā rauemi mai i tētahi whetū hoa ki roto (accretion), ka puta he pahūtanga hihi-X.
I taua wā tonu, ka taea e ngā hihi o te ao tūroa—ngā matūriki tino kaha e haere ana i te wāhi—te tukinga ki ngā āhuarangi o ngā aorangi, ki ngā mea rānei o waenga-whetu, ka puta te pakaru, ka pakaru ngā karihi ki ngā huānga māmā ake pērā i te lithium, te beryllium, me te boron. Koinei te take he onge noa iho ētahi huānga māmā ake i roto i te hanumitanga o ngā whetu, engari kei te kitea tonu i roto i te taiao.
He mea tino nui anō hoki ngā neutrino. Kāore ēnei matūriki e taunekeneke ki ngā mea, engari he nui te rahinga e puta mai ana i roto i ngā pūtake o ngā whetū, inā koa i ngā wā o ngā supernova. Mā te kitenga o ngā neutrino mai i ngā supernova (pērā i a SN 1987A) ka kitea tika ngā tukanga karihi me ngā whanaketanga karihi kāore e kitea mā te mārama anake.
Me pēhea te rangahau a ngā kaipūtaiao?
He mara e hono ana ngā momo mātauranga ki te ahupūngao whetū karihi. Ko ōna tikanga ko:
1. Ngā tirohanga whetū: Ka whakamahia te tirotiro whetū hei tautuhi i ngā huānga o roto i ngā whetū me ngā nebulae mā roto i ngā rārangi whetū. Mā te nui o ngā huānga ka kitea ngā tukanga karihi e puta ana.
2. Ngā whakamātautau ahupūngao karihi: I roto i te taiwhanga, ka inehia e ngā kaipūtaiao te whakawhiti-wāhanga o ngā tauhohenga i ngā pūngao e pā ana ki ngā āhuatanga o ngā whetu. Ko te wero ko te maha o ngā tauhohenga i roto i ngā whetu ka puta i ngā pūngao iti me ngā tūponotanga iti, nō reira me whakamahi ngā taputapu kite tino tairongo me ngā taputapu motuhake mō ngā whakamātautau.
3. Ngā whakatauira rorohiko: Nā te mea he maha ngā tukanga e puta ana i raro i ngā āhuatanga tino kino, ā, he nui hoki ngā whatunga tauhohenga e uru ana, ka whakamahia ngā tauira tau hei whakatauira i te whanaketanga o ngā whetu, ngā supernovae, me te hanganga huānga.
4. Ngā matūriki whetū: Ka tāpirihia ngā mōhiohio mai i te mārama e kitea ana e ngā kitenga o ngā neutrino, ngā hihi gamma, me ngā ngaru ā-papa, ā, ka hangaia te wā o te "whetu whetū maha-karere".
Whakamutunga
Ko te ahupūngao whetū karihi te ako i te āhua o ngā tauhohenga karihi e whakakaha ana i ngā whetū, e whakaoho ana i ngā huihuinga nui whakaharahara o te ao, me te hanga i ngā huānga matū e hanga ana i te ao e karapoti nei i a tātou. Mai i te hanumitanga hauwai i roto i te Rā ki ngā pahūtanga supernova me ngā hanumitanga whetū niutron e whakaputa ana i ngā huānga taumaha, he wāhanga katoa ēnei o te kōrero kotahi: i whanake te ao mā roto i ngā tukanga karihi. Ko te mārama ki te ahupūngao whetū karihi ko te mārama ki ngā takenga mai o te matū, te hītori o ngā whetū, me ngā tikanga taketake e hanga ana i te ao ki tōna āhua o nāianei.
Ki te hiahia koe, ka taea e au te hanga i tētahi putanga rongonui ake o tēnei tuhinga (he reo māmā ake), he putanga mātauranga ake rānei (me ngā tātai, ngā tauira tauhohenga, me ngā tohutoro ki ngā ariā pēnei i te mekameka pūmua-pūmua, te toru-ārepa, me te tukanga s/r me ētahi atu taipitopito).
