Free Astronomy Magazine September-October 2024

thandisksaroundhigh-massstars. A program called the MIRI (Mid- Infrared Instrument) Mid-INfrared Disk Survey (MINDS) aims to use Webb’s unique capabilities to builda bridge between the chemical in- ventory of disks and the propertiesof exoplanets. “Webbhasbettersensitivityand spectralresolutionthanpreviousin- frared space telescopes,” explained lead author Aditya Arabhavi of the University of Groningen in the Netherlands. “These observations arenotpossiblefromEarth,because the emissions from the disk are blocked by our atmosphere.” Inanewstudy,thisteamexplored the region around a very low-mass star known as ISO-ChaI 147, a 1 to 2 million-year-oldstarthatweighs just 0.11timesasmuchastheSun.The spectrum revealed by Webb’s MIRI shows the richest hydrocarbon chemistry seen to date in a proto- planetarydisk–atotalof13differ- entcarbon-bearingmolecules.The ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 15 رﺳﻢ ﺗﺨ ﻠﻲ ـﺎر ـﻢﺷـﺎب ﻣﺤـﺎط ﻘـﺮصﻣـﻦ اﻟﻐـﺎز واﻟﻐ ﻋﻦ ﻧ . اﺳـﺘﺨﺪم ﻓﺮ ـﻖ دوﻟـﻲﻣـﻦ ﻋﻠﻤـﺎء اﻟﻔﻠـﻚ ـﺐ اﻟﻔﻀـﺎﺋﻲ اﻟﺘـﺎﺑﻊ ﻟ ﺗﻠﺴـ ﻮبﺟـ ﻤﺲو ﻮ ﺎﻟـﺔ ﻧﺎﺳـﺎ ﻟﺪراﺳـﺔ اﻟﻘـ ـﻢﺷـﺎب وﻣـﻨﺨﻔﺾ اﻟﻜﺘﻠـﺔ ﺮصﺣـﻮل ﻧ اً ﺟﺪ ﻌﺮف ﺎﺳﻢ ISO-ChaI147 . وﺗﻜﺸﻒ اﻟﻨﺘﺎﺋﺞ اﻵن ـﺔ ﺷـﻮﻫﺪتﺣـ ـﺎء ﻫ ﺪروﻛﺮﻮﻧ ﻛ ﻤ ﻋـﻦ أﻏـ أوﻟﻲ ﻓﻲﻗﺮص ﻮﻛ ] . NASA-JPL [ - ﺳﺒﺘﻤﺒﺮ ﺃﻛﺘﻮﺑﺮ 2 0 2 4 ذات اﻟﻜﺘﻠﺔ اﻟﻌﺎﻟﻴﺔ وﻳﻬﺪف ﺑﺮﻧﺎﻣﺞ ﻳﺴﻤﻰ MIRI) ( أداة اﻷﺷــﻌﺔ ﺗﺤ ــﺖ اﻟﺤﻤـــﺮاء ا ﺘﻮﺳـﻄﺔ ( ﺴـﺢ ﻗـﺮص اﻷﺷـﻌﺔ ﺗﺤـﺖ اﻟﺤﻤﺮاء ا ﺘﻮﺳﻄﺔ (MINDS) إﱃ اﺳﺘﺨﺪام ﻗﺪرات وﻳـﺐ اﻟﻔﺮﻳـﺪة ﻟﺒﻨـﺎء ﺟـ ـ ﴪ ﺑـ ا ﺨﺰون اﻟﻜﻴﻤﻴﺎﺋﻲ ﻟﻸﻗـﺮاص وﺧﺼـﺎﺋﺺ اﻟﻜﻮاﻛﺐ اﻟﻨﺠﻤﻴﺔ . أوﺿﺢ ا ﺆﻟﻒ اﻟﺮﺋـ ﻴﴘ ـ أدﻳﺘﻴﺎ أراﺑﻬﺎﰲ ﻣـﻦ ﺟﺎﻣﻌـﺔ ﺟـﺮوﻧﻴﻨﺠﻦ ﰲ ــــ : " ﻫﻮﻟﻨﺪا ﻳﺘﻤﺘﻊ ﺗﻠﺴﻜﻮب وﻳﺐ ﺑﺤﺴﺎﺳـﻴﺔ ودﻗـﺔ ﻃﻴﻔﻴــﺔ أﻓﻀـﻞ ﻣـﻦ اﻟﺘﻠﺴـﻜﻮﺑﺎت اﻟﻔﻀﺎﺋﻴﺔ اﻟﺴـﺎﺑﻘﺔ اﻟﺘـﻲ ﺗﻌﻤـﻞ ﺑﺎﻷﺷـﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮ اء ." ﻫﺬه اﻷ رﺻﺎد ﻏـ ﻣﻤﻜﻨـﺔ ﻣـﻦ اﻷرض ﻷن اﻻﻧﺒﻌﺎﺛـﺎت اﻟﺼـﺎدر ة ﻋـﻦ اﻟﻘﺮص ﻳﺤﺠﺒﻬﺎ ﻏﻼﻓﻨﺎ اﻟﺠﻮي . ﰲ دراﺳﺔ ﺟﺪﻳﺪة اﺳﺘﻜﺸـﻒ ﻫـﺬا اﻟﻔﺮﻳـﻖ ا ﻨﻄﻘﺔ ا ﺤﻴﻄﺔ ﺑ ﻨﺠﻢ ﻣﻨﺨﻔﺾ اﻟﻜﺘﻠﺔ ﺟﺪ اً ﻳُﻌﺮف ﺑﺎﺳـﻢ ISO-ChaI 147 وﻫـﻮ ﻧﺠـﻢ ﻋﻤﺮه ﻣﻦ ﻋﺎم إﱃ ﻣﻠﻴﻮن ﻋﺎم وﻳـﺰن ﺣـﻮاﱄ 0.11 ﺿﻌﻒ ﺣﺠﻢ اﻟﺸﻤﺲ . ﻳُﻈﻬ ـﺮ اﻟﻄﻴــﻒ اﻟــﺬي ﻛﺸ ـﻔﻪ ﺟﻬ ـﺎز (MIRI) اﻟﺘﺎﺑﻊ ﻟﺘﻠﺴﻜﻮب وﻳﺐ أﻏﻨﻰ ﻛﻴﻤﻴﺎء ﻫﻴﺪروﻛﺮﺑﻮﻧﻴﺔ ﺷ ﻮﻫﺪت ﺣﺘﻰ اﻵن ﰲ ﻗﺮص ﻛﻮﻛﺒﻲ أوﱄ إﺟﻤـﺎﱄ 13 ﺟﺰﻳﺌـﺎت ﻣﺨﺘﻠﻔـﺔ ﺣﺎﻣﻠﺔ ﻟﻠﻜﺮﺑﻮن