Umubumbe w’ubururu ahagwa imvura y’ibirahure kandi “unuka nk’amagi yaboze”
Roberto Molar Candanosa/Johns Hopkins UniversityUmubumbe HD 189733 b uri ku ntera y’imyaka-urumuri 64 uvuye hano ku Isi. Hagwa imvura y’amabuye ashashagirana nk’ibirahure kandi haba imiyaga irenza umuvuduko wa 800km ku isaha
Uwo mubumbe utari mu mibumbe igaragiye izuba wari usanzwe uzwiho ikirere cy’ubushyuhe buteye ubwoba. Ariko hari ikindi kiwuranga cyavumbuwe: unuka nk’amagi yaboze.
Abahanga muri siyanse bo kuri kaminuza ya John Hopkins muri Leta Zunze Ubumwe za Amerika, bakoresheje amakuru yatanzwe na ya ndebakure idasanzwe James Webb maze biga uyu mubumbe wa kure witwa HD 189733 b.
Ni umubumbe rutura w’ubururu ufite ubunini nk’ubwa Jupiter, iyi iruta inshuro 11 mu bunini uyu mubumbe wacu w’isi.
Ikirere cy’uriya mubumbe kirimo ibimenyetso by’umwuka wa sulfure d’hydrogène (H₂S), iyi ni molécule ubusanzwe itanga kunuka kudasanzwe kw’amagi yaboze ndetse no kunuka kw’imisuzi.
“Iyaba izuru ryawe ryashobora kwinukiriza mu bushyuhe bwa 1,000 °C, ikirere cy’aho hantu cyakunukira nk’igi ryaboze”, ni ibivugwa na Guangwei Fu, inzobere mu bumenyi bw’isanzure wo kuri kaminuza ya John Hopkins wayoboye ubwo bushakashatsi.
HD 189733 b iri ku ntera y’imyaka-urumuri (light-years) 64 uvuye ku isi. Abahanga bavuga ko ‘light-years’ imwe ireshya na kilometero tiriyari icyenda (9.000.000.000.000km).
Abahanga mu by’isanzure bavuga ko uyu mubumbe ari “Jupiter ishyushye” iri hafi hashoboka babasha kureba, kandi ari wo wakozweho ubushakashatsi bwinshi mu mibumbe yo hanze y’igaragiye izuba (solar system/système solaire), kuva wavumburwa mu 2005, nk’uko Fu abisobanura.
Bifata iminsi ibiri yo ku isi kugira ngo uyu mubumbe ubashe kwizengurukaho. Ubaho ubushyuhe bukabije bugera kuri 1,000 °C ndetse ugwaho imvura y’amabuye ashashagirana nk’ibirahure (crystals), kandi haba imiyaga igira umuvuduko wa 8,000 km ku isaha.
“Ntabwo turi gushakayo ubuzima”
Kuvumbura ‘molecule’ ya ‘sulfure d’hydrogène’ kuri HD 189733 b biri mu kuboneka kwa mbere kwabayeho kwa ‘sulfure d’hydrogène’ hanze y’imibumbe igaragiye izuba.
Nubwo ‘sulfure d’hydrogène’ ari umwe mu myuka isobanuye ko imibumbe ya kure ishobora kubaho ibinyabuzima bitari ibya hano ku isi, abashakashatsi ntabwo barimo gushaka ubuzima kuri uyu mubumbe, kuko ari umubumbe w’imyuka kimwe na Jupiter, kandi urashyushye bikabije.
Gusa, kuvumburayo ‘sulfure d’hydrogène’ ni intambwe mu gusobanukirwa ukubaho kw’imibumbe, nk’uko abashakashatsi babivuga.
Roberto Molar Candanosa/Johns Hopkins University Légende image,Fu agira ati: “Ntabwo dushaka ubuzima kuri uriya mubumbe kuko ushyushye cyane, ariko kuvumburayo ‘sulfure d’hydrogène’ ni ikintu gikomeye mu kumenya uko imibumbe inyuranye ibaho”.
Uretse kubona ‘sulfure d’hydrogène’ mu kirere cya HD 189733 b, abahanga muri siyanse banapimye ahantu h’ibanze hava imyuka ya oxygène na carbone kuri uyu mubumbe, ni ukuvuga: amazi, ‘dioxyde de carbone’ na ‘monoxyde de carbone’.
Fu ati: “ ‘sulfure’ ni ikintu cy’ingenzi mu kubaho kw’ibindi binyabutabire nka carbone, azote, oxygène na phosphate, abahanga muri siyanse bagomba gushakisha kurushaho kugira ngo bamenye uko imibumbe yirema n’ibiyigize.”
Ibyuma by’amayobera
Abashakashatsi basesenguye kandi imyuka ya méthane kuri dans HD 189733 b maze bapima ikigero cy’ibyuma biyirimo.
Imibumbe minini cyane y’urubura nka Neptune na Uranus, ifite ibyuma byinshi kurusha imibumbe minini cyane y’imyuka nka Jupiter na Saturne, iyi ni nayo iruta iyindi mu igaragiye izuba.
Kugaragara kw’ibyuma byinshi ku mibumbe ya Neptune na Uranus gusobanuye ko mu kwirema kw’ibanze kw’iyi mibumbe yagize urubura rwinshi, amabuye n’ibindi bintu biremereye ugereranyije n’imyuka nka hydrogène na hélium.
Abahanga muri siyanse ntibarasubanukirwa impamvu y’ibyuma kuri uriya mubumbe w’ubururu, bityo barashaka kumenya niba ibyabaye kuri Neptune cyangwa Jupiter ari nako byagenze ku mibumbe yo hanze y’igaragiye izuba nk’uyu, nk’uko Fu abisobanura.
Ati: “Ubu rero dufite ibipimo bishya byerekana ko mu by’ukuri, kuba hari ibyuma byinshi kuri uriya mubumbe [HD 189733 b] ari ikintu cy’ingenzi cyo kwiga”.
Indebakure y’impinduramatwara
Ahavuye isanamu,NASA, ESA, CSA, Northrop Grumman
Indebakure (Telescop) James Webb yafunguye idirishya rishya mu gusesengura ibinyabutabire bigize imibumbe ya kure cyane yacu, ituma abahanga mu isanzure bamenya byinshi ku nkomoko yayo.
Fu ati: “Mu by’ukuri [James Webb ] yahinduye ubumenyi bw’isanzure. Yakoze ibyo yari yitezweho ndetse hamwe na hamwe yarengeje ibyari biyitezweho.”
Mu mezi ari imbere, ikipe ya Fu irateganya gukorashe amakuru (data) y’iriya ndebakure mu gushakisha umwuka wa ‘sulfur’ ku yindi mibumbe yo hanze y’igaragiye izuba, kugira ngo bamenye uko yabayeho bagereranyije n’inyenyeri nkuru igaragiye. (urugero; inyenyeri nkuru mu mibumbe igaragiye izuba ni izuba).
Ibyabonywe n’aba bashakashatsi byatangajwe mu kinyamakuru cya siyanse Nature.
