ORION TANA HAIFAR TAURARI A RAƘUMI, KOWACE SHEKARA MILIYAN 5

Ana haifar taurari a cikin gizagizai na iskar gas, sau da yawa a cikin manyan rukunoni da ke ci gaba da samar da sababbin zuriyoyi tsawon miliyoyin shekaru. Yadda wannan samarwa ke gudana yana faɗi abubuwa da yawa game da abin da ke tafiyar da shi. Shin samuwar taurari tana tafiya ne ba tare da tsari ba, ko tana bin tsare-tsare da za a iya sake ginawa? Shin tsofaffin taurari ne ke jawo sababbi, waɗanda iskarsu da fashewarsu ke matse iskar gas da ke kewaye?

Babu yarjejeniya, in ji takardar: wani bita na 2022 ya samu ƙaramar shaida ko babu ta tsare-tsare masu daidaito. Raba rukunonin taurari matasa da suka warwatse dalla-dalla ya zama mai yiwuwa ne kawai saboda tauraron ɗan Adam Gaia, wanda ke auna wurare da motsin taurari a faɗin sararin sama.

Misali a maƙwabta

A cikin rukunin Scorpius-Centaurus na kusa, wani bincike da aka wallafa a 2023 ya samu tsare-tsare masu daidaito a sarari da lokaci, har da lokuta da yawa na ƙaruwar samuwar taurari da tazarar kusan shekaru miliyan 5, suna yaɗuwa daga ciki zuwa waje, kamar tasirin taurarin da suka gabata ne ke tafiyar da su. Shin haka zai kasance a Orion, yankin samuwar taurari mafi yawan nazari a kusa da mu?

Alena Rottensteiner, João Alves da abokan aikinsu a Jami’ar Vienna, tare da masu bincike a Barcelona, Prague, Cambridge (Massachusetts) da Cibiyar Lura ta Kudancin Turai (European Southern Observatory), sun yi amfani da wani sabon ƙidayar Orion da aka gina daga bayanan Gaia: rukunonin taurari 47, masu shekaru miliyan 1.5 zuwa 25, tare da membobi 11,996 masu inganci, kuma an samo shekarun ta hanya ɗaya ga kowane rukuni. A wannan aikin, “cluster” na nufin cunkoson taurari na ƙididdiga, ba lallai rukuni da nauyi ke riƙe shi tare ba.

Raƙumi huɗu

Shekarun ba su yi santsi ba. Idan aka auna su da yawan taurarinsu, suna samar da ƙololuwa huɗu, a shekaru miliyan 6.4, 11.3, 16.2 da 21.4, tazararsu shekaru miliyan 5.0, 4.8 da 5.2. Kowace ƙololuwa tana ɗauke da taurari fiye da wadda ta gabace ta.

Rarraba shekarun rukunoni 47 na Orion, an auna su da yawan membobinsu (sama) ko ba a auna ba (ƙasa); an yi wa ƙololuwa huɗu da tazararsu alama. — Hoto na 1, Rottensteiner da abokan aiki (2026), arXiv:2610.00481.

Marubutan suna taka-tsantsan game da abin da suke iƙirari:

• Ƙololuwa biyu mafi kusa da yau, a shekaru miliyan 6.4 da 11.3, za a iya gano su ta ƙididdiga, tare suna ɗauke da kusan kashi 59% na dukan taurari, kuma suna tsira idan aka sake ɗaukar samfurin bayanan da canje-canje a yadda ake daidaita shekaru. Wani gwaji na ƙololuwa da yawa ya ƙi yarda da kumburi guda santsi ga rarraba taurari a matakin 10%.
• Ƙololuwa biyu mafi tsufa, a shekaru miliyan 16.2 da 21.4, ana ganin su amma ba za a iya nuna cewa suna da ƙarfi ba tukuna. Tsofaffin rukunoni sun rasa kusan kashi ɗaya cikin uku na membobinsu, waɗanda suka yi nesa, kuma hakan yana raunana alamarsu.
• Ƙasa da kashi 0.5% na tarihohi santsi 10,000 da aka kwaikwaya ne ke samar da gibi uku masu tsari kamar waɗannan. Marubutan sun jaddada cewa wannan bayani ne game da ƙololuwar da ke cikin hotonsu, “ba iƙirarin cewa lokuta huɗu daban-daban sun faru tabbas ba”.

Sun kuma tabbatar cewa hanyar ba za ta iya ƙirƙirar tsarin ba. Matakin rarraba rukunoni yana amfani da wurare da motsi kawai, ba shekaru ba. Kuma grid ɗin shekaru yana da tazara daidai a cikin logarithm na lokaci, wanda ba zai iya samar da ƙololuwa masu tazara daidai a cikin lokacin kansa ba. Rukunonin da aka haifa a raƙumi ɗaya kuma suna zama kusa da juna: kashi 68% suna da maƙwabci mafi kusa a ƙololuwa ɗaya, idan aka kwatanta da kashi 34% idan da an rarraba ƙololuwar ba tare da tsari ba.

Bugu ɗaya, rawa daban

Sabanin Scorpius-Centaurus, Orion ba ta nuna tsari ɗaya na yaɗuwa zuwa waje a faɗin dukan rukunin ba. Maimakon haka, ƙungiyar ta samu jerin abubuwa na gida: sarƙoƙin rukunonin taurari uku masu yiwuwa da ke ƙara ƙuruciya a tsawonsu, ɗaya daga cikinsu yana miƙewa kusan parsec 130 daga gajimaren Orion A zuwa taurarin Ɗamarar Orion, da yankuna biyu na rukunoni masu alaƙa. Biyu daga cikin sarƙoƙin suna farawa ne a cikin wani rami mai faɗaɗawa da aka sani da Orion Shell kuma suna ƙara ƙuruciya zuwa waje.

Marubutan ba su ga wani saɓani da samuwar taurari da tasirin taurari ke tafiyarwa ba. Orion ta fi Scorpius-Centaurus nauyi, tana da ragowar iskar gas da yawa, kuma babbar fashewarta ita ce ta kwanan nan, yayin da Scorpius-Centaurus ta kai ƙololuwa shekaru miliyan 15 da suka wuce. Ƙarin iskar gas da ƙarin taurari matasa masu nauyi suna barin sarari ga mu’amaloli masu sarƙaƙiya: tasirin taurari zai iya matse iskar gas zuwa sababbin taurari, ko ya tarwatsa gizagizai.

Taurarin da aka binne, bugun da ba a sani ba

Taurari matasa sosai da har yanzu ke binne a cikin ƙura ba su cikin ƙidayar Gaia — tsakanin kusan ’yan takara 1,850 zuwa 2,430. Za su iya ƙara ƙololuwa ta biyar, ta kwanan nan, ko da yake ba za su canza huɗun da aka riga aka samu ba. Ainihin shekaru kuma sun dogara da samfuran taurari da aka yi amfani da su, da shekaru miliyan 1 zuwa 3.

Abin da ya rage shi ne kari da aka gani a gidajen haihuwar taurari biyu daban-daban. “Dalilin tazarar ~shekaru miliyan 5 har yanzu asiri ne,” in ji marubutan; mai yiwuwa yana da alaƙa da saurin da tasirin taurari ke tafiya ta cikin iskar gas, tambayar da suka bari don ƙarin bincike.