Free Astronomy Magazine January-February 2024 ARABIC VERSION

A Rocky planets can form in extreme environments by NASA/ESA/CSA Bethany Downer n international team of as- tronomers has used NASA’s James Webb Space Telescope to provide the first observation of water and other molecules in the highly irradiated inner, rocky-planet- forming regions of a disk in one of the most extreme environments in our galaxy. These results suggest that the conditions for rocky planet formation can occur in a possible broader range of environments than previously thought. These are the first results from the eXtreme Ultraviolet Environments (XUE) James Webb Space Telescope program, which focuses on the char- acterization of planet-forming disks (vast, spinning clouds of gas, dust, and chunks of rock where planets form and evolve) in massive star- forming regions. These regions are likely representative of the environ- ment in which most planetary sys- tems formed. Understanding the impact of environment on planet formation is important for scientists to gain insights into the diversity of the different types of exoplanets. The XUE program targets a total of 15 disks in three areas of the Lobster Nebula (also known as NGC 6357), a large emission nebula roughly 5,500 light-years away from Earth in the constellation Scorpius. The Lobster Nebula is one of the youngest and closest massive star-formation com- plexes, and is host to some of the most massive stars in our galaxy. Massive stars are hotter, and there- fore emit more ultraviolet (UV) radi- ation. This can disperse the gas, making the expected lifetime of the disk as short as a million years. Thanks to Webb, astronomers can now study the effect of UV radiation on the inner terrestrial-planet form- ing regions of protoplanetary disks around stars like our Sun. “Webb is the only telescope with the spatial resolution and sensitivity to study planet-forming disks in massive star-forming regions,” said team lead María Claudia Ramírez- Tannus of the Max Planck Institute for Astronomy in Germany. Astronomers aim to characterize the physical properties and chemical composition of the rocky-planet- JANUARY-FEBRUARY 2024 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 42 اﻟ ﻮاﻛـــــﺐ اﻟﺼـــــﺨﺮ ﺔ ﻤﻜـــــﻦ أن ﺗﺘﺸ ﻞﻓﻲاﻟﺒﻴﺌﺎت اﻟﻘﺎﺳ ﺔ : ﻘﻠﻢ ﺑ ﺜﺎﻧﻲ داوﻧﺮ و ﺎﻻت اﻟﻔﻀﺎء ﻧﺎﺳﺎ ا ﺴﺎ / / اﻟﻜﻨﺪ ﺔ اﺳـﺘﺨﺪم ﻓﺮﻳ ـﻖ دوﱄ ﻣـﻦ ﻋﻠﻤـﺎء اﻟﻔﻠ ـﻚ ﺗﻠﺴﻜﻮب ﺟﻴﻤﺲ وﻳﺐ اﻟﻔﻀﺎﺋﻲ اﻟﺘﺎﺑﻊ ﻟﻨﺎﺳﺎ ﻟﺘﺤﻘﻴﻖ أول رﺻﺪ ﻟﻠﻤﻴﺎه واﻟﺠﺰﻳﺌﺎت اﻷﺧﺮى ﰲ ا ﻨــﺎﻃﻖ اﻟﺪاﺧﻠﻴــﺔ اﻟﺼــﺨﺮﻳﺔ ا ﻜﻮﻧــﺔ ﻟﻠﻜﻮاﻛﺐ ﺷﺪﻳﺪة اﻹﺷﻌﺎع ﰲ اﻟﻘﺮ صﰲ واﺣﺪة ﻣﻦ أﻛﺜﺮ اﻟﺒﻴﺌﺎت ﺗﻄﺮﻓ ﺎً . ﰲ ﻣﺠﺮﺗﻨﺎ ﺗﺸ ﻫـﺬه اﻟﻨﺘـﺎﺋﺞ إﱃ أن ﻇـﺮوف ﺗﻜـﻮﻳﻦ اﻟﻜﻮاﻛﺐ اﻟﺼﺨﺮﻳﺔ ﻳﻤﻜﻦ أن ﺗﺤﺪث ﰲ ﻧﻄﺎق أوﺳﻊ ﻣﻦ اﻟﺒﻴﺌﺎت ا ﺤﺘﻤﻠﺔ ﻣﻤﺎ ﻛﺎن ﻳُﻌﺘﻘـﺪ إن . ﺳﺎﺑﻘًﺎ ﻫﺬه ﻫﻲ اﻟﻨﺘﺎﺋﺞ اﻷوﱃ ﻣﻦ ﺑﺮﻧﺎﻣﺞ ﺟﻴﻤﺲ وﻳـﺐ ﻟﺘﻠﺴـﻜﻮب اﻟﻔﻀـﺎء ﻟﻠﺒﻴﺌـﺎت اﻟﻘﺎﺳـﻴﺔ ﻋ ـﱪ اﻟﻀـﻮء ﻓ ـﻮق اﻟﺒﻨﻔﺴـﺠﻲ اﻟﺬي (ﺷﻮي ) ﻳﺮﻛﺰ ﻋﲆ ﺗﻮﺻـﻴﻒ اﻷﻗـﺮاص ا ﻜﻮﻧﺔ ﻟﻠﻜﻮاﻛﺐ ) ﺳﺤﺐ ﺿﺨﻤﺔ ودوارة ﻣﻦ اﻟﻐﺎز واﻟﻐﺒﺎر وﻗﻄـﻊ ﻣـﻦ اﻟﺼـ ﺨﻮر ﺣﻴـﺚ ﺗﺘﺸﻜﻞ اﻟﻜﻮاﻛﺐ وﺗﺘﻄﻮر ( ﰲ ﻣﻨﺎﻃﻖ ﺗﺸﻜﻴﻞ اﻟﻨﺠﻮم اﻟﻀﺨﻤﺔ . ﻣﻦ ا ﺮﺟﺢ أن ﺗﻤﺜﻞ ﻫﺬه ا ﻨﺎﻃﻖ اﻟﺒﻴﺌﺔ اﻟﺘﻲ ﺗﺸﻜﻠﺖ ﻓﻴﻬﺎ ﻣﻌﻈﻢ اﻷﻧﻈﻤﺔ اﻟﻜﻮﻛﺒﻴـﺔ إن . ﻓﻬﻢ ﺗﺄﺛ اﻟﺒﻴﺌﺔ ﻋﲆ ﺗﻜـﻮﻳﻦ اﻟﻜﻮ ﻛـﺐ أﻣـﺮ ﻣﻬﻢ ﻟﻠﻌﻠﻤﺎء ﻻﻛﺘﺴﺎب ﻧﻈـﺮة ﺛﺎﻗﺒـﺔ ﺣـﻮل ﻣﺪى اﻷﻧـﻮاع ا ﺨﺘﻠﻔـﺔ ﻟﻠﻜﻮاﻛـﺐ اﻟﻨﺠﻤﻴـﺔ . ـــــــ ﻳﺴﺘﻬﺪف ﺑﺮﻧﺎﻣﺞ (ﺷﻮي ) ﻣﺎ ﻣﺠﻤﻮﻋـﻪ 15 ﰲ ﺎً ﻗﺮﺻ ﺛﻼث ﻣﻨﺎﻃﻖ ﻣﻦ ﺳﺪﻳﻢ ﺟﺮاد اﻟﺒﺤﺮ ا ﻌﺮوف أﻳﻀًـﺎ ﺑﺎﺳـﻢ (NGC 6357) وﻫـﻮ ﺳﺪﻳﻢ اﻧﺒﻌﺎﺛﻲ ﻛﺒ ﻳﺒﻌﺪ ﺣ ﻮاﱄ 5500 ﺳـﻨﺔ ﺿﻮﺋﻴﺔ ﻋﻦ اﻷرض ﰲ ﻛﻮﻛﺒﺔ ا ﻟﻌﻘـﺮب . ﻳﻌـﺪ ﺳﺪﻳﻢ ﺟﺮاد اﻟﺒﺤﺮ واﺣﺪ اً ﻣﻦ أﺣـﺪث و أﻗـﺮب ﻣﺠﻤﻌــﺎت ﺗﻜــﻮﻳﻦ اﻟﻨﺠــﻮم اﻟﻀـــﺨﻤﺔ وﻳﺴﺘﻀﻴﻒ ﺑﻌﻀـ ﺎً ﻣـﻦ أﺿـﺨﻢ اﻟﻨﺠـﻮم ﰲ . ﺮﺗﻨﺎ ﻣﺠ اﻟﻨﺠﻮم اﻟﻀﺨﻤﺔ أﻛﺜﺮ ﺳﺨﻮﻧﺔ وﺑﺎﻟﺘﺎﱄ ﺗﺒﻌﺚ ﻗﺪراً أﻛﱪ ﻣﻦ اﻷﺷﻌﺔ ﻓﻮق اﻟﺒﻨﻔﺴﺠﻴﺔ ﺬا وﻫ ﻳﺆدي إﱃ ﺗﺒﺪﻳﺪ اﻟﻐﺎز و ﺑﺎﻟﺘﺎﱄ ﺗﻘﺼـ اﻟﻌﻤـﺮ ا ﺘﻮ ﻗﻊ ﻟﻠﻘﺮص إﱃ ﻣﺎ ﻳﻘﺎرب ﻣﻠﻴـﻮن ﺳـﻨﺔ . ـ ـــ ـ ﺑﻔﻀﻞ ﺗﻠﺴﻜﻮب وﻳﺐ ﻳﺴﺘﻄﻴﻊ ﻋﻠﻤﺎء اﻟﻔﻠﻚ اﻵن دراﺳﺔ ﺗﺄﺛ اﻷﺷﻌﺔ ﻓـﻮق اﻟﺒﻨﻔﺴـﺠﻴﺔ ﻋـﲆ ﻣﻨــﺎﻃﻖ ﺗﺸــﻜﻞ اﻟﻜﻮاﻛ ـﺐ اﻷرﺿـﻴﺔ اﻟﺪاﺧﻠﻴﺔ ﻣﻦ اﻷﻗﺮاص اﻟﻜﻮﻛﺒ ﻴﺔ اﻷوﻟﻴﺔ ﺣﻮل ﻧﺠﻮم ﻣﺜﻞ ﺷﻤﺴـﻨﺎ . ﻗﺎﻟـﺖ ﻗﺎﺋـﺪة اﻟﻔﺮﻳـﻖ ﻣﺎرﻳﺎ ﻛﻠﻮدﻳﺎ راﻣ ﻳـﺰ - ﺗـﺎﻧﻮس ﻣـﻦ ﻣﻌﻬـﺪ ﻣﺎﻛﺲ ﺑﻼﻧﻚ ﻟﻌﻠﻢ اﻟﻔﻠﻚ ﰲ أ ﺎﻧﻴﺎ " : إن وﻳـﺐ ﻫﻮ اﻟﺘﻠﺴﻜﻮب اﻟﻮﺣﻴﺪ اﻟـﺬي ﻳﺘﻤﺘـﻊ ﺑﺎﻟﺪﻗـﺔ ا ﻜﺎﻧﻴﺔ واﻟﺤﺴﺎﺳﻴﺔ ﻟﺪراﺳﺔ أﻗﺮاص ﺗﺸﻜﻴﻞ اﻟﻜﻮاﻛـــﺐ ﰲ ﻣﻨـــﺎﻃﻖ ﺗﺸــﻜ ﻞ اﻟﻨﺠــﻮم اﻟﻀﺨﻤﺔ ." ﻳﻬﺪف ﻋﻠﻤﺎء اﻟﻔﻠـﻚ إﱃ ﺗﻮﺻـﻴﻒ اﻟﺨﺼﺎﺋﺺ اﻟﻔﻴﺰﻳﺎﺋﻴﺔ واﻟﱰﻛﻴﺐ اﻟﻜﻴﻤﻴـﺎﺋﻲ ﻨـﺎﻃﻖ اﻷﻗـﺮاص اﻟﺼـﺨﺮﻳﺔ اﻟﺘـﻲ ﺗﺸـﻜﻞ ــــــ - ﻳﻨﺎﻳﺮ ﻓﺒﺮﺍﻳﺮ 2 0 2 4