Free Astronomy Magazine November-December 2024 ARABIC VERSION

ence Foundation Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory in Chile, a Program of NSF NOIRLab. LocatedintheconstellationMonoc- eros(theUnicorn),theRosetteNeb- ulaspans1.3degreesofsky,roughly the width of an index finger held outatarm’slength.Forcomparison, the well-known Orion Nebula, lo- catedintheconstellationOrionjust below the hunter’s belt, spans one degreeofsky.AlthoughtheRosette Nebulahasadiameterof130light- years—morethanfivetimesas large as the Orion Nebula — their apparent sizes are similar because theformerisfourtimesasdistant. Asprominentasthenebula’s‘petals’ istheconspicuousabsenceofgasat its center. The culprits responsible for excavating this hollow core are themostmassivestarsofNGC2244 —theopenstarclusternurturedby the nebula. This cluster was born around two million years ago after the nebula’s gasses coalesced into clumps brought together by their mutual gravity. Eventually, some clumps grew to be massive stars thatproducestellarwindspowerful enough to bore a hole in the neb- ula’s heart. NGC 2244’s massive stars also emit ultraviolet radiation, which ionizes the surrounding hydrogen gas andlights up the nebula in an array ofbrilliantcolors.Thebillowingred clouds are regions of H-alpha emis- sion,resultingfromhighlyener- gizedhydrogenatomsemittingred NOVEMBER-DECEMBER2024 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 23 اﻟﺘﺎﺑﻊ ﻟﻠﻤﺆﺳ ﺴﺔ اﻟﻮﻃﻨﻴﺔ ﻟﻠﻌﻠﻮم ﺑﺎﻟﻮﻻﻳﺎت ا ﺘﺤﺪة ﰲ ﻣﺮﺻﺪ ﺳ رو ﺗﻮﻟﻮﻟـﻮ ﰲ ﺗﺸـﻴﲇ وﻫﻮ ﺑﺮﻧﺎﻣﺞ ﺗﺎﺑﻊ ﺨﺘـﱪ ﻧـﻮﻳﺮﻻب اﻟﺘـﺎﺑﻊ ﻮﺳﺴﺔ اﻟﻌﻠﻮم اﻟﻮﻃﻨﻴﺔ اﻻﻣﺮﻳﻜﻴﺔ . ﻳﻘﻊ ﺳﺪﻳﻢ اﻟﻮردة ﰲ ﻛﻮﻛﺒﺔ وﺣﻴـﺪ اﻟﻘـﺮن وﻳﻤﺘﺪ ﻋﲆ ﻣﺴﺎﻓﺔ 1.3 درﺟﺔ ﻣـﻦ اﻟﺴـﻤﺎء أي ﻣﺎ ﻳﻌﺎدل ﺗﻘﺮﻳﺒ ﺎً ﻋﺮض إﺻﺒﻊ اﻟﺴـﺒﺎﺑﺔ ﻋﻨﺪ رﻓﻌﻪ إﱃ ﻃﻮل اﻟﺬراع وﻟﻠﻤﻘﺎرﻧﺔ ﻳﻤﺘـﺪ ﺳﺪﻳﻢ اﻟﺠﺒﺎر ا ﻌﺮ وف واﻟﺬي ﻳﻘﻊ ﰲ ﻛﻮﻛﺒﺔ اﻟﺠﺒﺎر أﺳﻔﻞ ﺣﺰام اﻟﺼـﻴﺎد ﻣﺒـﺎﴍة ﻋـﲆ ﻣﺴﺎﻓﺔ درﺟﺔ واﺣـﺪة ﻣـﻦ اﻟﺴـﻤﺎء وﻋـﲆ اﻟﺮﻏﻢ ﻣﻦ أن ﻗﻄﺮ ﺳﺪﻳﻢ اﻟﻮردة ﻳﺒﻠـﻎ 130 ﺳﻨﺔ ﺿﻮﺋﻴﺔ أي أﻛﺜﺮ ﻣﻦ ﺧﻤﺴﺔ أﺿـﻌﺎف ﺣﺠ ـﻢ ﺳ ـﺪﻳﻢ اﻟﺠﺒ ـﺎر ﻓ ـﺈن أﺣﺠﺎﻣﻬﻤ ـﺎ اﻟﻈﺎﻫﺮﻳﺔ ﻣﺘﺸﺎﺑﻬﺔ ﻷن ﺳﺪ ﻳﻢ اﻟﻮردة ﻳﺒﻌـﺪ ﻋﻨﺎ ﺑﺄرﺑﻌﺔ أﺿﻌﺎف ﺑﺘﻼت" وﻣﻦ ﺑ ﺳﺪﻳﻢ " اﻟﻮردة ﻏﻴﺎب اﻟﻐﺎز اﻟﻮاﺿﺢ ﰲ ﻣﺮﻛﺰه . إن اﻟﺠﻨﺎة ا ﺴﺌﻮﻟ ﻋﻦ ﺣﻔﺮ ﻫـﺬ ه اﻟﻨـﻮاة ا ﺠﻮﻓ ﻲﻫـ ﺔ اﻟﻨﺠـﻮم اﻷﻛﺜـﺮ ﺿـﺨﺎﻣﺔ ﰲ اﻟﻌﻨﻘﻮد اﻟﻨﺠﻤﻲ ا ﻔﺘﻮح NGC 2244 اﻟﺬي ﻳﺤﺘﻀﻨﻪ اﻟﺴﺪﻳﻢ . وُﻟِـﺪ ﻫـﺬا اﻟﻌﻨﻘـﻮد ﻣﻨـﺬ ﺣﻮاﱄ ﻣﻠﻴﻮﻧﻲ ﻋﺎم ﺑﻌﺪ أن اﻧﺪﻣﺠﺖ ﻏـﺎزات اﻟﺴﺪﻳﻢ ﰲ ﻛﺘﻞ ﺟﻤﻌﺘﻬﺎ ﺟﺎذﺑﻴ ﺘﻬﺎ ا ﺘﺒﺎدﻟـﺔ وﰲ اﻟﻨﻬﺎﻳﺔ ﻧﻤﺖ ﺑﻌﺾ اﻟﻜﺘﻞ ﻟﺘﺼﺒﺢ ﻧﺠﻮﻣ ﺎً ﺿﺨﻤﺔ ﺗﻨﺘﺞ رﻳﺎﺣ ﺎً ﻧﺠﻤﻴﺔ ﻗﻮﻳﺔ ﺑﻤﺎ ﻳﻜﻔﻲ ﻟﺤﻔﺮ ﺛﻘﺐ ﰲ ﻗﻠﺐ اﻟﺴﺪﻳﻢ . ﻛﻤﺎ ﺗﺼﺪر اﻟﻨﺠﻮم اﻟﻀﺨﻤﺔ ﰲ NGC 2244 إﺷﻌﺎﻋ ﺎً ﻓـﻮق ﺑﻨﻔﺴـﺠﻴﺎ ﻣﻤـﺎ ﻳـﺆﻳﻦ ﻏـﺎز اﻟﻬﻴ ـﺪروﺟ ا ﺤ ـﻴﻂ وﻳ ـ ـ ﻢ ﴤء اﻟﺴ ـﺪﻳ ﺑﻤﺠﻤﻮﻋﺔ ﻣﻦ اﻷﻟﻮان اﻟﺮاﺋﻌﺔ . اﻟﺴﺤﺐ اﻟﺤﻤﺮاء ا ﺘﺼـﺎﻋﺪة ﻫـﻲ ﻣﻨـﺎﻃﻖ اﻧﺒﻌﺎث ﻫﻴﺪروﺟ أﻟﻔﺎ اﻟﻨﺎﺗﺠـﺔ ﻋـﻦ ذرات اﻟﻬﻴﺪروﺟ ﻋﺎﻟﻴﺔ اﻟﻄﺎ ﻳ ﻗﺔ اﻟﺘﻲ ﻨﺒﻌﺚ ﻣﻨﻬﺎ اﻟﻀﻮء اﻷﺣﻤﺮ وﻋﲆ ﻃﻮل ﺟﺪران اﻟﺘﺠﻮﻳـﻒ ﻣﻦ اﻟﺴﻴﻠﻴﻜﻮن ا ﺘﺄﻳﻦ . ﺳــــــﺪ ﻢ اﻟـــــــﻮردة اﻟ ﻮﻧ ـــــــﺔ ﻤـــــــﺎ رﺻـــــــﺪﺗﮫ ) ـــــــــﺎم د ( ـــــــــﺎﻣ ا اﻟﻄﺎﻗـــــــــﺔ اﻟﻤﻈﻠﻤــــــــــﺔ ﻋﻠﻰﻫﻴﺌﺔ ﻓ ﺪﻳﻮ . [CTIO/NOIRLab/DOE/ NSF/AURA/N. Bartmann/T.Slovinský −Image Processing: T.A. Rector (Universityof Alaska Anchorage/NSF NOIR- Lab), D. de Martin&M.Za- mani(NSF NOIRLab) − Music:Stellardrone– Airglow] ﻧﻮﻓﻤﺒﺮ - ﺩﻳﺴﻤﺒﺮ 2 0 2 4 ا ﺮﻛــﺰي و أﻗـﺮب إﱃ اﻟﻨﺠـﻮم ا ﺮﻛﺰﻳ ـﺔ اﻟﻀﺨﻤﺔ ﻳﻜـﻮن اﻹﺷـﻌﺎع ﻧﺸـﻄًﺎ ﺑﻤـﺎ ﻳﻜﻔﻲ ﻟﻠﻌﻤﻞ ﻋﲆ ﺗـﺄﻳﻦ ذرة أﺛﻘـﻞ ﻣﺜـﻞ اﻷﻛﺴﺠ واﻟﺘﻲ ﺗﺘـﻮﻫﺞ ﰲ ﻇـﻼل ﻣـﻦ اﻟﻠﻮن اﻷﺻﻔﺮ اﻟﺬﻫﺒﻲ . وأﺧ اً ﻳﺮﺻﺪ ﻛﺬﻟﻚ ﻋـﲆ ﻃـﻮل ﺣـﻮاف ﺑـﺘﻼت اﻟـ ﺳـﺪﻳﻢ ﻮردة ﺧﻴـﻮط رﻗﻴﻘـﺔ ﺗﻜﺘـﴘ اﻟﻠﻮن اﻟﻮردي اﻟﻌﻤﻴﻖ وﻫﻮ ﻧﺎﺗﺞ ﻋــﻦ ﺗــﻮﻫﺞ اﻟﻀــﻮء ا ﻨﺒﻌــﺚ ﻣــﻦ اﻟﺴﻴﻠﻴﻜﻮن ا ﺘﺄﻳﻦ .