Free Astronomy Magazine July-August 2023 ARABIC VERSION

convective and therefore do not carry information about the ele- ments generated in the thermonu- clear forge to the surface. The crux of the matter is precisely to understand whether the nucleus of Betelgeuse is burning helium or carbon. The models would be decisive if it were possible to “feed” them with less ap- proximate data, but since, as we have seen, this is not feasi- ble, wide freedom of interpre- tation remains, so much so that Saio’s team comes to question the paradigm of fun- damentality of the 400-420 day period, proposing that in- stead it is the one of about 2200 days that is fundamental. This would lead to a different estimate of the star’s size and a different current evolution- ary stage, with the conse- quence that Betelgeuse would already be going through the carbon fusion phase, which would significantly shorten the supernova wait time. In fact, a star with an initial mass of about twenty solar masses, the entrance to the main sequence, runs out of hydrogen in about 10 million years, helium in about one million years, carbon in just a thou- sand years. The subsequent contrac- tions of the nucleus and consequent fusions of increasingly heavier ele- ments last less and less time, until the photodisintegration of the silicon, which ends in about a day and can hinder the continuation of the chain towards nickel, cobalt and iron, ele- ments which are the last gen- erated by the stars in the imminence of their explosion. All the heavier elements pres- ent in nature are instead pro- duced by supernovae. The majority of specialists in the sector favor the scenario in which the fusion of helium into carbon is still taking place in the nucleus of Betel- geuse, also because it is about a thousand times more likely. But if reality were the one described by Saio’s team, we could be on the eve of a grandiose and rare galactic event. Considering that Betelgeuse is 600 (±100) light years away from us, the explosion may have already occurred, while we continue to see the star as it was hundreds of years ago and some amount of time as Betelgeuse probably was at prior to the explosion.     ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 9 ﺗﻈﻬـﺮ ﻫــﺬﻩ اﻟﺼــﻮراﻟــﺜﻼث اﻟــﻨ ﻢ ـ ﻣﻨﻜــﺐ اﻟــ ﺠﻮزاء اﻟ ﺴــﺎر : ﺻــﻮرة ــﺎس اﻟﺘــﺪاﺧﻞ ﻟﻠﻔﻮﺗﻮﺳــﻔ ، اﻟ ﻗ : ﻮﺳــﻂ ﺻــﻮرة ﺼــﺮ ﺔ ﺗ ــﺔ ـﺔ اﻷﻟــﻮان ﻣﺮﻛ ــﺔ ﺛﻼﺛ ﻜ ﻔ وﻋﻠﻰ اﻟ ﻤ : ﺻﻮرة ﻋﻨﺪ ١٠.٤٩ ﻣ ﻜﺮوﻣ ﻣﻦ اﻻﻧ ﻌﺎث اﻟ ـ ﺤﺮاري ﻟﻠﻐ ﺎر اﻟﻤﺤ ﻂ ] . ـﻮﻛﺲ، وﺧﻮﺳـ ﮫ إﺗـﺶ ـﮫ ـﻚ إل ﺟ ﺎﺋﻴﻞ ﻧﺰي ، وﺷ ﺎو ﺗﺸـﻲ ، وﻧ ﻟﻲ ، وﻣﻴ ﺎ ﻮ ﻣﺎﺗﺴﻮرا ، وﺳﺎﻟﻲ أوي ، وﺟﺎي إسﺳ ﻨﻐﻔﻴﻞ د ﺟﺮوﻩ ، وﻣﺎر ﻦ ﻏ ﺮو ، وﺑﻴ ﻛ ﻓ ﻼ ، وﺷ - ﻟﻮ ، وﺳﺘ ﻔﺎﻧﻲواﺗﺸ [ وﺑﺎﻟﺘﺎﱄ ﻻ ﺗﺤﻤﻞ ﻣﻌﻠﻮﻣﺎت ﺣﻮل اﻟﻌﻨـﺎﴏ ا ﺘﻮﻟــﺪة ﰲ اﻻﻧ ـﺪﻣﺎج اﻟﻨ ـﻮوي ﺣ ـﺮاري اﱃ اﻟﺴﻄ . ﺢ ان ﺟﻮﻫﺮ اﻷﻣﺮ ﻋﲆ وﺟﻪ اﻟﺘﺤﺪﻳﺪ ﻫﻮ ﻓﻬـﻢ ﻣﺎ إذا ﻛﺎﻧﺖ ﻧـﻮاة ﻣﻨﻜـﺐ اﻟﺠـﻮزاء ﺗﺤـﺮق اﻟﻬﻴﻠﻴﻮم أو اﻟﻜﺮﺑﻮن ﻟـﺬﻟﻚ ﺳـﺘﻜﻮن اﻟﻨﻤﺎذج ﺣﺎﺳﻤﺔ إذا ﻛﺎن ﻣﻦ ا ﻤﻜـﻦ " ﺗﻐﺬﻳﺘﻬﺎ " ﺑﺒﻴﺎﻧﺎت أﻗﻞ ﺗﻘﺎرﺑﺎً وﻟﻜﻦ ﺑﻤﺎ أن ﻫﺬا ﻏ ﻣﻤﻜـﻦ ، ﻛﻤـﺎ رأﻳﻨـﺎ ﻓـﻼ ﺗـ ﺰال ﻫﻨـﺎك ﺣﺮﻳـﺔ واﺳـﻌﺔ ﰲ اﻟﺘﻔﺴ ﻟﺪرﺟﺔ أن ﻓﺮﻳﻖ ﻳﺄﺗﻲ ﺳﺎﻳﻮ ﻟﻠﺘﺸﻜﻴﻚ ﰲ ﻧﻤﻮذج اﻷﺳﺎﺳﻴﺎت ﻟﻔﱰة 400 - 420 ﻳﻮﻣًﺎ ﻳﻘﱰح أﻧﻪ ﺑﺪﻻً ﻣﻦ ذﻟﻚ ﻫﻮ واﺣﺪ ﻣﻦ ﺣﻮاﱄ 2200 ﻳﻮﻣًـﺎ ﻳﻌﺘﱪ أﻣﺮًا أﺳﺎﺳﻴًﺎ وﻫﺬا ﺳـﻴﺆدي إﱃ ﺗﻘﺪﻳﺮ ﻣﺨﺘﻠﻒ ﻟﺤﺠﻢ ا ﻟﻨﺠﻢ وﻣﺮﺣﻠﺔ ﺗﻄﻮر ﺣﺎﻟﻴﺔ ﻣﺨﺘﻠﻔﺔ ﻣﻤﺎ ﻳـﺆدي إﱃ أن ﻣﻨﻜ ـﺐ اﻟﺠ ـﻮزاء ﻳﻤ ـ ﺮ ﺑﺎﻟﻔﻌ ـﻞ ﺑﻤﺮﺣﻠﺔ اﻧﺪﻣﺎج اﻟﻜﺮﺑﻮن واﻟﺘﻲ ﻣـﻦ ﺷﺄﻧﻬﺎ ﺗﻘﺼ وﻗﺖ اﻧﺘﻈﺎر ﺣـﺪوث ا ﺴـﺘﻌﺮ اﻷﻋﻈـﻢ ﺑﺸـﻜﻞ ﻛﺒـ ﰲ . اﻟﺤﻘﻴﻘﺔ أن ﻧﺠﻢ ﻛﺘﻠﺘﻪ اﻷوﻟﻴﺔ ﺗﺒﻠـﻎ ـ ﺣﻮاﱄ ﻋﺸ ﺮﻳﻦ ﻛﺘﻠﺔ ﺷﻤﺴـﻴﺔ ﻣﺜـﻞ ﻣﻨﻜﺐ اﻟﺠﻮزاء ﻣﻦ ا ﺤﺘﻤﻞ أن ﻳﻜﻮن ﻋﻨﺪ ﻣﺪﺧﻞ اﻟﺘﺴﻠﺴﻞ ﻴﴘـ اﻟﺮﺋ ﻧﻔـﺪ ﺣﻴـﺚ ﻣﻨﻪ اﻟﻬﻴﺪروﺟ ﰲ ﺣﻮاﱄ ة ﻋﺸــﺮ ﻣﻼﻳـ ﺳــﻨﺔ واﻟﻬﻴﻠﻴ ـﻮم ﰲ ﺣـﻮاﱄ ﻣﻠﻴــﻮن ﺳــﻨﺔ واﻟﻜﺮﺑﻮن ﰲ أﻟﻒ ﺳﻨﺔ ﻓﻘﻂ . ﺗﺴــﺘﻤﺮ اﻻﻧﻜﻤﺎﺷــﺎت اﻟﻼﺣﻘــﺔ ﻟﻠﻨــﻮاة ــــــــ واﻻﻧﺪﻣﺎج اﻟﻼﺣـﻖ ﻟﻌﻨـﺎﴏ أﺛﻘـﻞ ﺑﺸـﻜﻞ ﻣﺘﺰاﻳﺪ وﻗﺘًﺎ أﻗﻞ وأﻗﻞ ﺣﺘﻰ اﻟﺘﻔﻜﻚ اﻟﻀﻮﺋﻲ ﻟﻠﺴﻴﻠﻴﻜﻮن واﻟﺬي ﻳﻨﺘﻬﻲ ﰲ ﻏﻀـﻮن ﻳـﻮم ﺗﻘﺮﻳﺒًﺎ وﻳﻤﻜﻦ أن ﻳﻌﻴﻖ اﺳﺘﻤﺮار اﻟﺴﻠﺴـﻠﺔ ﻧﺤـﻮ اﻟﻨﻴﻜــﻞ واﻟﻜﻮﺑﺎﻟــﺖ واﻟﺤﺪﻳـﺪ وﻫـﻲ ــــــ ﻋﻨﺎﴏ آﺧﺮ ﻣﺎ اﻧﺘﺠﺘﻪ اﻟﻨﺠﻮم ﻋﻨـﺪ اﻗ ﱰاب اﻧﻔﺠﺎرﻫﺎ . ﺑﺪﻻً ﻣﻦ ذﻟﻚ ﻳـﺘﻢ إﻧﺘــﺎج ﺟﻤﻴــﻊ اﻟﻌﻨــﺎﴏ اﻷﺛﻘــﻞ ا ﻮﺟــﻮدة ﰲ اﻟﻄﺒﻴﻌـــﺔ ﺑﻮاﺳــﻄﺔ ا ﺴﺘﻌﺮات اﻟﻌﻈﻤﻰ . ﻳﻔﻀﻞ ﻏﺎﻟﺒﻴﺔ ا ﺘﺨﺼﺼـ ﰲ ﻫـﺬا ا ﺠﺎل اﻟﺴﻴﻨﺎرﻳﻮ اﻟﺬي ﻻ ﻳـﺰال ﻓﻴـﻪ اﻧﺪﻣﺎج اﻟﻬﻠﻴﻮم ﰲ اﻟﻜ ﺮﺑﻮن ﻳﺤﺪث ﰲ ﻧـﻮاة ﻣﻨﻜـﺐ اﻟﺠـﻮزاء أﻳﻀًـ ﺎ ﻷﻧ ـﻪ اﺣﺘﻤﺎل أﻛﱪ ﺑﻨﺤﻮ أﻟﻒ ﻣﺮة ﻟﻜﻦ إذا و ﻛﺎﻧﺖ اﻟﺤﻘﻴﻘﺔ ﻫـﻲ اﻟﺘـﻲ وﺻـﻔﻬﺎ ﻓﺮﻳﻖ ﺳﺎﻳﻮ، ﻓﻘﺪ ﻧﻜﻮن ﻋﺸﻴﺔ ﺣﺪث ﻣﺠﺮي اﺳﺘﺜﻨﺎﺋﻲ . وﻧﺎدر ﺑﺎﻟﻨﻈﺮ إﱃ أن ﻣﻨﻜﺐ اﻟﺠـﻮزاء ﻳﺒﻌـﺪ ﻋﻨـﺎ 600 ) ± 100 ( ﺳـﻨﺔ ﺿـﻮﺋﻴﺔ ﻓﻘﺪ ﻳﻜﻮن اﻻﻧﻔﺠﺎر ﻗﺪ ﺣﺪث ﺑﺎﻟﻔﻌﻞ ﺑﻴﻨﻤﺎ ﻧﺴﺘﻤﺮ ﰲ رؤﻳﺔ اﻟﻨﺠﻢ ﻛﻤﺎ ﻛﺎن ﻣﻨﺬ ﻣﺌﺎت اﻟﺴﻨ وﺑﻌﺾ اﻟﻮﻗﺖ ﻗﺒﻞ ﺣﺪوث اﻻﻧﻔﺠﺎر . ﻳﻮﻟﻴﻮ - ﺃﻏﺴﻄﺲ 2 0 2 3 ﺗُﻈﻬـﺮﻫــﺬﻩ اﻟﺼـﻮر اﻟﻌﻤــﻼق اﻷ ﻤـﺮ ﻣﻨﻜــﺐ اﻟــ ـ ﻨــ ﺾو ﺘﻀـ ﻢ ﺠﻮزاء اﻟــﺬ و ﻨ ﻤﺶ ﺸ ﻞ ﻏ ﻣﺘﻤﺎﺛﻞ ﻓﻲ اﻷﺷﻌﺔ ﻓﻮق اﻟ ﻨﻔﺴﺠ ﺔ . ] Alex Lobel, Andrea Dupree, Ronald Gilliland, CfA, STScI, NASA, ESA [