Free Astronomy Magazine July-August 2026 ARABIC VERSION

T his image shows a section of one of the spiral arms of Messier 51 (M51), one of the four galaxies studied in this work, as seen by Webb’s Near-Infrared Camera (NIRCam). The thick clumps of star-forming gas are shown here in red and orange, representing infrared light emitted by ionised gas, dust grains, and complex molecules such as polycyclic aromatic hydrocarbons (PAHs).Withinthesegascomplexes,eachtensorhundredsoflightyearsacross,Webbrevealsthedense,extremelybrightclus- ters of massive stars that have just recently formed. The countless stars strewn across the arm of the galaxy, many of which wouldbeinvisibletooureyesbehindlayersofdust,arealsolaidbareininfraredlight.[ESA/Webb,NASA&CSA,A.Pedrini, A. Adamo(Stockholm University)and theFEAST JWSTteam] By observing nearby galaxies, as- tronomers can survey thousands of star-forming regions and charac- teriseentirepopulationsofstarclus- tersatmanystagesofevolution—a featmadepossiblewiththelaunch of space telescopes, most promi- nently the NASA/ESA Hubble Space Telescope. Both kinds of investiga- tion are necessary to truly under- stand how star formation takes place in galaxies. The continuous development of in- frared astronomy has allowed us to pull back the gaseous curtains that still hide the youngest star clusters and learn about the earliest stagesof their development, but some sub- jects still puzzle researchers. For in- stance: when a star cluster forms, what determines how long it takesto disperse its natal cloud and begin radiating ultraviolet light out into the galaxy? Now, the state of the art has been furtherdevelopedwithbothHubble andWebbworkingtogethertopro- videabroad-spectrumviewofthou- sands of young star clusters. An international team of astron- omers has pored over images of four nearby galaxies — Messier 51, Messier83,NGC628,andNGC4449 — from the FEAST observing pro- gramme(#1783),tryingtosolvethismy stery.Theirresults,publishedin JULY-AUGUST2026 ﺗﻈﻬﺮ ﻫﺬﻩ اﻟﺼﻮرة ﺟﺰء اً ﻣﻦ أﺣﺪ اﻷذرع اﻟ ـ ﺤﻠﺰوﻧ ﺔ ﻟﻤﺠﺮة ﻣﺴﻴ ﮫ 51 )M51 ( اﻟﻤﺠﺮا وﻫﻲ إﺣﺪ ت اﻷرﻊ ا درﺳﺖ ﻓﻲﻫﺬا اﻟﻌﻤﻞ ﻟ ﻤﺎ ر ﺻﺪت ﺑﻮاﺳﻄﺔ ﺎﻣ ا اﻷﺷــﻌﺔ ﺗﺤــﺖ اﻟــ ـ ــﺔ ﻤﺮاء اﻟﻘﺮ ــﺎم ) ﻧ ( ــﺐ اﻟﻔﻀـﺎﺋﻲ اﻟﺘﺎ ﻌــﺔ ﻟﺘﻠﺴــ ﻮبﺟــ ﻤﺲو . اﻷ ﻤــﺮواﻟ ﻘــﺎﻟﻲ، ــﺎﻟﻠﻮﻧ ﺗﻈﻬــﺮﻫﻨــﺎ ﻛﺘــﻞ ﻛﺜ ﻔــﺔ ﻣــﻦ اﻟﻐــﺎز اﻟﻤُﺸــ ﻞ ﻟﻠﻨﺠــﻮم ﻣُﻤﺜﻠــﺔً ﺿــﻮء اﻷﺷــﻌﺔ ﺗﺤــﺖ اﻟــ ـ ــﺎت اﻟ ﻤﺮاء اﻟﻤﻨ ﻌــﺚ ﻣــﻦ اﻟﻐــﺎزاﻟﻤﺘــﺄﻳﻦ وﺣﺒﻴ ــﺎر ﻐ ـ واﻟــ ﺠﺰ ﺌﺎت اﻟﻤ ــﺪروﻛﺮﻮﻧﺎت اﻟﻌﻄﺮ ــﺔ ﻣﺘﻌــﺪدة اﻟــ ﻌﻘــﺪة ﻣﺜــﻞ اﻟﻬ ـ ) ﺤﻠﻘﺎت PAH .( ـﺐ ﻋـﻦ ﺗ ﻤﻌـﺎت ﻛﺜ ﻔـﺔ ﺷـﺪ ﺪة اﻟﺴـﻄﻮع ﻣـ اﻟﻀـﻮﺋ ﺔ، ﻜﺸـﻒ ﺗﻠﺴـ ﻮب و ـﻞ ﻣﻨﻬـﺎ ﻋﺸـﺮات أو ﻣﺌـﺎت اﻟﺴـﻨ ﻳ ﻠـﻎ ﻗﻄـﺮ ﺿﻤﻦ ﻫﺬﻩ اﻟﻤُﺮﻛ ﺎت اﻟﻐﺎز ـﺔ، اﻟـ ﻦ اﻟﻨﺠـﻮم ﺗﺸ ﻠﺖﺣﺪ ﺜ اﻟﻀ ﻤﺔ اﻟ . ﺎً ﻤﺎ ﺗﻈﻬـﺮﺑﻮﺿـﻮح ﻓـﻲﺿـﻮء اﻷﺷـﻌﺔ ﺗﺤـﺖ اﻟـ ـ ﻻ ﺗﺤﺼـﻰواﻟﻤﻨﺘﺸـﺮة ﻋـ ذراع اﻟﻤﺠـﺮة ﻤﺮاء اﻟﻨﺠـﻮم اﻟـ ﺳـﻴ ﻮن اﻟﻜﺜـ ﻣﻨﻬـﺎ ﻏـ واﻟـ اﻟﻤﺠﺮدة ﺧﻠﻒﻃ ﻘﺎت اﻟﻐ ﺎر ﻣﺮﻲ ﻟﻠﻌ . [ESA/Webb, NASA & CSA, A. Pedrini,A. Adamo (Stockholm University) and the FEAST JWST team] ﻫـﺬه ا ﻨـﺎﻃﻖ وﻣـﻦ ﺧـﻼل رﺻـﺪ ا ﺠـﺮات اﻟﻘﺮﻳﺒــﺔ ﻳﺴـﺘ ﻄﻴﻊ اﻟﻔﻠﻜﻴــﻮن ﻣﺴـﺢ آﻻف ﻣﻨﺎﻃﻖ ﺗﻜﻮّن اﻟﻨﺠـﻮم ووﺻـﻒ ﻣﺠﻤﻮﻋـﺎت ﻛﺎﻣﻠـﺔ ﻣـﻦ اﻟﻌﻨﺎﻗﻴـ ﺪ اﻟﻨﺠﻤﻴـﺔ ﰲ ﻣﺨﺘﻠـﻒ ﻣﺮاﺣﻞ ﺗﻄﻮرﻫﺎ وﻫﻮ إﻧﺠـﺎز أﺻـﺒﺢ ﻣﻤﻜﻨـ ﺎً ﺑﻔﻀﻞ إﻃﻼق اﻟﺘﻠﺴﻜﻮﺑﺎت اﻟﻔﻀﺎﺋﻴﺔ ﺑﺮزﻫﺎ وأ ﺗﻠ ﺴﻜﻮب ﻫﺎﺑﻞ اﻟﻔﻀﺎﺋﻲ اﻟﺘﺎﺑﻊ ﻟﻮﻛﺎﻟﺔ ﻧﺎﺳﺎ ووﻛ ﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑﻴﺔ . ﻛﻼ اﻟﻨـﻮﻋ ﻣـﻦ اﻟﺪراﺳﺎت ﴐورﻳ ﺎن ﻟﻔﻬﻢ ﺣﻘﻴﻘﻲ ﻟﻜﻴﻔ ﻴـﺔ ﺣﺪوث ﺗﺸﻜّﻞ اﻟﻨﺠﻮم ﰲ ا ﺠﺮات وﻗﺪ ﺳـﻤﺢ اﻟﺘﻄﻮر ا ﺴﺘﻤﺮ ﰲ ﻋﻠﻢ اﻟﻔﻠﻚ ﺑﺎﻷﺷﻌﺔ ﺗﺤـﺖ اﻟﺘﻄﻮر ا ﺴﺘﻤﺮ ﰲ ﻋﻠﻢ اﻟﻔﻠﻚ ﺑﺎﻷﺷﻌﺔ ﺗﺤـﺖ اﻟﺤﻤﺮاء ﺑﻜﺸﻒ اﻟﺴﺘﺎر اﻟﻐﺎزي اﻟﺬي ﻣﺎ ﻳﺰال ﻳﺨﻔﻲ أﺻﻐﺮ اﻟﻌﻨﺎﻗﻴﺪ اﻟﻨﺠﻤﻴﺔ واﻟﺘﻌﺮف ﻋﲆ ا ﺮاﺣﻞ ا ﺒﻜﺮة ﺟﺪ اً ﻣﻦ ﺗﻄﻮرﻫﺎ ﻟﻜﻦ ﺑﻌـﺾ اﻷﺳﺌﻠﺔ ﻻ ﺗﺰال ﺗﺤ اﻟﺒﺎﺣﺜ . ﻋﲆ ﺳﺒﻴﻞ ا ﺜﺎل : ﻋﻨﺪﻣﺎ ﻳﺘﻜﻮّن ﻋﻨﻘﻮد ﻧﺠﻤﻲ ﻣﺎ اﻟﺬي ﻳ ﺤﺪد ا ﺪة اﻟﺘـﻲ ﻳﺴـﺘﻐﺮﻗﻬﺎ ﻟﺘﺒﺪﻳـﺪ اﻟ ﺴﺤﺎﺑﺔ اﻟﺘﻲ وﻟـﺪ ﻓﻴﻬـﺎ واﻟﺒـﺪء ﰲ إﺻـﺪار اﻹﺷﻌﺎ ع ﻓﻮق اﻟﺒﻨﻔﺴﺠﻲ إﱃ ا ﺠﺮة؟ اﻵن ﺗـﻢ ﺗﻄﻮﻳﺮ أﺣﺪث ﻣﺎ وﺻﻞ إﻟﻴﻪ اﻟﻌﻠﻢ ﻋﱪ ﺗﻌﺎون ﻛـﻞ ﻣـﻦ ﺗﻠﺴـﻜﻮب ﻫﺎﺑـﻞ و James Webb ﻛﻞ ﻣﻦ ﺗﻠﺴﻜﻮب ﻫﺎﺑﻞ و ﺗﻠﺴـﻜﻮب ﺟـ ﻴﻤﺲ وﻳـﺐ ﻟﺘﻘـﺪﻳﻢ رؤﻳـﺔ واﺳـﻌﺔ اﻟﻄﻴـﻒ ﻵﻻف اﻟﻌﻨﺎﻗﻴﺪ اﻟﻨﺠﻤﻴﺔ اﻟﺸﺎﺑﺔ . وﻗﺪ ﻗﺎم ﻓﺮﻳﻖ دوﱄ ﻣـﻦ اﻟﻔﻠﻜﻴـ ﺑﺪراﺳـﺔ ﺻﻮر أرﺑﻊ ﻣﺠﺮات ﻗﺮﻳﺒﺔ ﻫـﻲ : ﻣﻴﺴـﻴﻴﻪ 51 ﻣﻴﺴﻴﻴﻪ 83 و NGC 628 و NGC 4449 وذﻟﻚ ﺿﻤﻦ ﺑﺮﻧﺎﻣﺞ اﻟﺮﺻﺪ # رﻗـﻢ ) ﻓﻴﺴﺖ 1783 ( ﰲ ﻣﺤﺎوﻟ ﺔ ﻟﺤﻞ ﻫﺬا اﻟﻠﻐﺰ . وأﻇﻬﺮت ﻧﺘﺎﺋﺠﻬﻢ ا ﻨﺸﻮرة ﰲ ﻣﺠﻠـﺔ ﻧﻴﺘــﴩ ﻟﻌﻠـﻢ اﻟﻔﻠـﻚ أن اﻟﻌﻨﺎﻗﻴﺪ اﻟﻨﺠﻤﻴﺔ اﻷﻛﺜﺮ ﺿﺨﺎﻣﺔ ﻫـﻲ اﻟﺘـﻲ ﺗُﺰﻳﻞ ﻏﻼﻓﻬـﺎ اﻟﻐـﺎزي ﺑﺸـﻜﻞ أﴎع، وﺗﺒـﺪأ - ﻳﻮﻟﻴﻮ ﺃﻏﺴﻄﺲ 2 0 2 6