Free Astronomy Magazine May-June 2026 ARABIC VERSION

MAY-JUNE2026 candidate, allowing researchers to target it for detailed follow-up study. “Without data from MAGIC,it would have been impossible to isolate this star among the hun- dredsofotherstarsinthevicinityof the Pictor II ultra-faint dwarf gal- axy,” says Chiti. By combining data from MAGIC,theMagellan/BaadeTelescop e,and ESO’s Very Large Telescope, the team found that PicII-503 has the lowestironandcalciumabundances evermeasuredoutsideoftheMilky Way. This paucity of iron and cal- cium makes it the first object that clearly preserves enrichment from thefirststarsinarelicdwarfgalaxy. “Discoveringastarthatunambigu- ously preserves the heavy metals fromthefirststarswasattheedge ofwhatwethoughtpossible,given theextremerarityoftheseobjects,” saysChiti. “Withthelowestiron abundanceeverderivedinanyultra- faintdwarfgalaxy,PicII-503provides a window into initial element pro- duction within a primordial system that is unprecedented.” Evenmoreremarkably,theteamdis- coveredthatPicII-503hasacarbon- to-ironratiothatisover1500times thatoftheSun.Thisoverabundance matches the distinct carbon signa- tureoflow-ironstarslongobserved in the Milky Way halo. These are known as carbon-enhanced metal- poor stars, and their origin has re- mained unknown until now. One hypothesis is that carbon-en- hanced metal-poor stars are second- generation stars that preserve the chemicalelementsproducedbylow- energy supernovae of first-genera- tionstars.Duringthisprocess,heavy elements that form close to the star’sinterior,likeiron,fallbackinto theremnantcompactobject,while lighter elements that are near thestar’souterregions,likecar- bon,areejectedintotheinter- stellarmediumtoseedthefor- mation of the next generation of stars. PicII-503 supports the low-energysupernovaeexplana- tionbecauseitisfoundinoneof thesmallestdwarfgalaxiesthat we know of. If the supernova that produced the metals found in PicII-503 was high-energy, then the elements would have escaped the gravita- tional pull of the small Pictor II dwarfgalaxy.PicII-503also demonstratesthatthecarbon- enhanced metal-poor stars ob- servedintheMilkyWayhalo likelyoriginatedfromancient relicdwarfgalaxiesthathave, overtime,mergedwithours. “Whatexcitesmethemostis that we have observed an out- come of the very initial element production in a primordial gal- axy, which is a fundamental ob- servation!” saysChiti. “Italso cleanlyconnectstothesignaturethat wehaveseeninthelowest-metallic- ity Milky Way halo stars, tying to- gethertheiroriginsandthefirst-star- enriched nature of these objects.” “Discoveries like this are cosmic ar- chaeology,uncoveringrarestellar fossilsthatpreservethefingerprints oftheUniverse’sfirststars ,”says ChrisDavis,NSFProgramDirector for NOIRLab. “We look forward tomanymorediscoverieswiththestart of the NSF–DOE Rubin Observatory’s LegacySurveyofSpaceandTime later this year.” PicII-503offersarare,directglimpse into the Universe’s first chapter of chemicalevolution,whichisafoun- dational moment that ultimately setthestageforplanets,chemistry, andlifeitself.Italsoconnectslong- standing mysteries about ancient stars in the Milky Way to their ori- ginsinprimordialdwarfgalaxies.  ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 38 ﻣﻊ أرﺻﺎد ﺗﻠﺴﻜﻮب ﻣﺎﺟﻼ ن ﺑﺎد واﻟﺘﻠﺴﻜﻮب اﻟﻜﺒ ﺟﺪ اً اﻟﺘﺎﺑﻊ ﻟﻠﻤﺮﺻﺪ اﻷوروﺑﻲ اﻟﺠﻨﻮﺑﻲ وﺟﺪ اﻟﻔﺮﻳﻖ أن اﻟﻨﺠﻢ PicII-503 ﻟﺪﻳﻪ أدﻧﻰ وﻓﺮة ﻣﻦ اﻟﺤﺪﻳـﺪ واﻟﻜﺎﻟﺴـﻴﻮم ﺗـﻢ ﻗﻴﺎﺳـﻬﺎ ﺧﺎرج . ﻣﺠﺮﺗﻨﺎ وﻳﺠﻌﻞ ﻫﺬا اﻟـﻨﻘﺺ اﻟﺸـﺪﻳﺪ ﰲ اﻟﺤﺪﻳﺪ واﻟﻜﺎﻟﺴﻴﻮم ﻣﻨﻪ أول ﺟـﺮم ﻳُﻈﻬـﺮ ﺑﺸﻜﻞ واﺿﺢ أﺛﺮ اﻹﺛﺮاء اﻟﻜﻴﻤﻴﺎﺋﻲ اﻟﻨﺎﺗﺞ ﻋﻦ اﻟﻨﺠﻮم اﻷوﱃ داﺧﻞ ﻣﺠﺮة ﻗﺰﻣﺔ . ﻗﺪﻳﻤﺔ ﻳﻘﻮل ﺗﺸﻴﺘﻲ :» إن اﻛﺘﺸـﺎف ﻧﺠـﻢ ﻳﺤـﺘﻔﻆ ﺑﺸﻜﻞ ﻻ ﻟﺒﺲ ﻓﻴـﻪ ﺑـﺎﻟﻔﻠﺰات اﻟﺜﻘﻴﻠـﺔ ﻣـﻦ اﻟﻨﺠﻮم اﻷوﱃ ﻛ ﺎن ﻋﻨﺪ ﺣﺪود ﻣﺎ اﻋﺘﻘﺪﻧﺎ أﻧـﻪ ﻣﻤﻜﻦ ﻧﻈﺮ اً ﻟﻨﺪرة ﻫﺬه اﻷﺟـﺮام اﻟﺸـﺪﻳﺪة « . وﻳﻀﻴﻒ :» ﻣﻊ أدﻧﻰ وﻓﺮة ﺣﺪﻳﺪ ﺗﻢ اﺷﺘﻘﺎﻗﻬ ﺎ ﰲ أي ﻣﺠﺮة ﻗﺰﻣﺔ ﻓﺎﺋﻘﺔ اﻟﺨﻔﻮت . ﻳﻮﻓّﺮ اﻟﻨﺠﻢ PicII-503 ﻧﺎﻓﺬة ﻏ ﻣﺴـﺒﻮﻗﺔ ﻋـﲆ إﻧﺘـﺎج اﻟﻌﻨـﺎﴏ اﻷوﻟﻴـﺔ داﺧـﻞ ﻧﻈـﺎم ﺑـﺪاﺋﻲ « . واﻷﻛﺜ ـﺮ ﻟﻔﺘ ـﺎً ﻟﻠﻨﻈــﺮ أن اﻟﻔﺮﻳ ـﻖ اﻛﺘﺸ ـﻒ أن ﻧﺴـﺒﺔ اﻟﻜﺮﺑ ـﻮن إﱃ اﻟﺤﺪﻳــﺪ ﰲ PicII-503 ﺗﺰﻳ ـﺪ ﺑــﺄﻛﺜﺮ ﻣــﻦ 1500 ﻣــﺮة ﻣﻘﺎرﻧﺔ ﺑﺎﻟﺸﻤﺲ وﺗﺘﻄﺎﺑﻖ ﻫﺬه اﻟﺰﻳﺎدة ﻣـﻊ اﻟﺒﺼﻤﺔ ا ﻤﻴﺰة ﻟﻠﻨﺠـﻮم ﻣﻨﺨﻔﻀـﺔ اﻟﺤﺪﻳـﺪ اﻟﺘﻲ رُﺻﺪت ﻣﻨﺬ زﻣﻦ ﻃﻮﻳﻞ ﰲ ﻫﺎﻟـﺔ ﻣﺠـﺮة اﻟﺒﺼﻤﺔ ا ﻤﻴﺰة ﻟﻠﻨﺠـﻮم ﻣﻨﺨﻔﻀـﺔ اﻟﺤﺪﻳـﺪ اﻟﺘﻲ رُﺻﺪت ﻣﻨﺬ زﻣ ﻦ ﻃﻮﻳﻞ ﰲ ﻫﺎﻟـﺔ ﻣﺠـﺮة درب اﻟﺘﺒﺎﻧﺔ وا ﻌﺮوﻓﺔ ﺑﺎﺳﻢ اﻟﻨﺠﻮم اﻟﻔ ﻘ ة ﺑﺎﻟﻔﻠﺰات وا ﻌﺰزة ﺑﺎﻟﻜﺮﺑﻮن واﻟﺘﻲ ﻇﻞ أﺻﻠﻬﺎ ﻣﺠﻬﻮﻻً ﺣﺘﻰ اﻵن . ﺗﻔﱰض إﺣﺪى اﻟﻔﺮﺿﻴﺎت أن ﻫﺬه اﻟﻨﺠﻮم ﻫﻲ ﻧﺠﻮم ﻣﻦ اﻟﺠﻴﻞ اﻟﺜـﺎﻧﻲ ﺗﺤـ ﺘﻔﻆ ﺑﺎﻟﻌﻨـﺎﴏ اﻟﻜﻴﻤﻴﺎﺋﻴﺔ اﻟﻨﺎﺗﺠﺔ ﻋـﻦ ﻣﺴـﺘﻌﺮات ﻋﻈﻤـﻰ ﻣﻨﺨﻔﻀﺔ اﻟﻄﺎﻗﺔ ﻟ ﻠﻨﺠﻮم اﻷوﱃ وﺧﻼل ﻫـﺬه اﻟﻌﻤﻠﻴﺔ ﺗﺴﻘﻂ اﻟﻌﻨـﺎﴏ اﻟﺜﻘﻴﻠـﺔ ا ﺘﺸـﻜﻠﺔ ﺑ ﺎﻟﻘﺮب ﻣﻦ داﺧﻞ اﻟﻨﺠﻢ ﻣﺜﻞ اﻟﺤﺪﻳﺪ ﺪةً إﱃ ﻋﺎﺋ اﻟﺒﻘﺎﻳ ـﺎ اﻟﻨﺠﻤﻴــﺔ ا ﺪﻣﺠــﺔ ﺑﻴﻨﻤــﺎ ﺗﻘــﺬف اﻟﻌﻨﺎﴏ اﻷﺧﻒ ﻣﺜﻞ اﻟﻜﺮﺑـﻮن ﻣـﻦ ا ﻨـﺎﻃﻖ اﻟﺨﺎ رﺟﻴﺔ ﻟﻠـﻨﺠﻢ إﱃ اﻟﻮﺳـﻂ ﺑـ اﻟﻨﺠﻤـﻲ ﻟﺘﺴﺎﻫﻢ ﰲ ﺗﻜﻮﻳﻦ اﻟﺠﻴﻞ اﻟﺘﺎﱄ ﻣـﻦ اﻟﻨﺠـﻮم . ﻳﺪﻋﻢ اﻟﻨﺠﻢ PicII-503 ﺗﻔﺴـ ا ﺴـﺘﻌﺮات اﻟﻌﻈﻤﻰ ﻣﻨﺨﻔﻀﺔ اﻟﻄﺎﻗﺔ ﻷﻧﻪ ﻳﻘﻊ ﰲ واﺣﺪة ﻣﻦ أﺻﻐﺮ ا ﺠﺮات اﻟﻘﺰﻣﺔ ا ﻌﺮوﻓﺔ . ﻓﻠﻮ ﻛﺎن اﻻﻧﻔﺠﺎر اﻟﻨﺠﻤﻲ اﻟﺬي أﻧـﺘﺞ اﻟﻌﻨـﺎﴏ ﻓﻴـﻪ ﻋﺎ ﱄ اﻟﻄﺎﻗﺔ ﻟﻜﺎﻧﺖ ﻫﺬه اﻟﻌﻨﺎﴏ ﻗـﺪ أﻓﻠﺘـﺖ ﻣـﻦ اﻟﺠﺎذﺑﻴـﺔ اﻟﻀـﻌﻴﻔﺔ ﺠـﺮة Pictor II ﻣﻦ اﻟﺠﺎذﺑﻴﺔ اﻟﻀﻌﻴﻔﺔ ﺠﺮة ﺑﻴﻜﺘﻮر II اﻟﺼﻐ ة . ﻈﻬﺮ ﻛﻤﺎ ﻳ اﻟـﻨﺠﻢ PicII-503 أن اﻟﻨﺠﻮم ا ﻌﺰزة ﺑـﺎﻟﻜﺮﺑﻮن واﻟﻔﻘـ ة ﺑﺎﻟﻔ ﻠﺰات ﰲ ﻫﺎﻟـﺔ ﻣﺠـﺮة درب اﻟﺘﺒﺎﻧـﺔ ﻳ ﺤﺘﻤﻞ أﻧﻬﺎ ﻧﺸﺄت ﰲ ﻣﺠﺮات ﻗﺰﻣﺔ أﺛﺮﻳﺔ ﻗﺪﻳﻤﺔ اﻧﺪﻣﺠﺖ ﻻﺣﻘ ﺎ ﻣﻊ ﻣﺠﺮﺗﻨﺎ ﻋـﱪ اﻟﺰﻣﻦ . ﻳﻘﻮل ﺗﺸﻴﺘﻲ :» ﻣﺎ ﻳﺜ ﺣﻤـﺎﳼ أﻛﺜﺮ ﻫﻮ أﻧﻨـﺎ رﺻـﺪﻧﺎ ﻧﺘﻴﺠـﺔ ﻣﺒـﺎﴍة ﻹﻧﺘﺎج اﻟﻌﻨﺎﴏ اﻷ وﻟﻴﺔ ﰲ ﻣﺠـﺮة ﺑﺪاﺋﻴـﺔ وﻫﻮ رﺻﺪ أﺳﺎﳼ ﻟﻠﻐﺎﻳﺔ « . وﻳﻀﻴﻒ :» ﻛﻤﺎ أﻧﻪ ﻳﺮﺑﻂ ﺑﺸﻜﻞ واﺿـﺢ اﻟﺒﺼﻤﺔ اﻟﺘﻲ ﻻﺣﻈﻨﺎﻫﺎ ﰲ ﻧﺠـﻮم ﻫ ﺎﻟـﺔ درب اﻟﺘﺒﺎﻧﺔ ﻣﻨﺨﻔﻀﺔ اﻟﻔﻠﺰﻳـﺔ ﻣﻮﺣـﺪ اً ﺑ أﺻﻮﻟﻬﺎ وﻃﺒﻴﻌﺘﻬﺎ ا ُﺜﺮﻳـﺔ ﺑﻌﻨـﺎﴏ اﻟ ﻨﺠﻮم اﻷوﱃ « . وﻳﻘﻮل ﻛـﺮﻳﺲ دﻳﻔـﻴﺲ ﻣﺪﻳﺮ ﺑﺮﻧﺎﻣﺞ ﰲ ﻣﺨﺘﱪ ﻧـﻮﻳﺮﻻب اﻟﺘـﺎﺑﻊ ﺆﺳﺴﺔ اﻟﻌﻠﻮم اﻟﻮﻃﻨﻴـﺔ :» ﻣﺜـﻞ ﻫـﺬ ه اﻻﻛﺘﺸﺎﻓﺎت ﺗﻤﺜﻞ ﻋﻠﻢ آﺛﺎر ﻛﻮﻧﻲ ﺣﻴـﺚ ﺗﻜﺸﻒ ﻋﻦ أﺣﺎﻓ ﻧﺠﻤﻴﺔ ﻧﺎدرة ﺗﺤﺘﻔﻆ ﺑﺒﺼــﻤﺎت اﻟﻨﺠــﻮم اﻷوﱃ ﰲ اﻟﻜــﻮن « . وﻳﻀــﻴﻒ :» ﻧﺘﻄﻠــﻊ إﱃ ا ﺰﻳــﺪ ﻣــﻦ اﻻﻛﺘﺸﺎﻓﺎت ﻣﻊ اﻧﻄﻼق ا ﺴـﺢ اﻹرﺛـﻲ ﻟﻠﺰﻣﺎن وا ﻜﺎن ﰲ ﻣﺮﺻﺪ روﺑـﻦ اﻟﺘـﺎﺑﻊ ﻟـﻮزارة اﻟﻄﺎﻗـﺔ اﻷﻣﺮﻳﻜﻴـﺔ وا ﺆﺳﺴـﺔ ا ﻟﻮﻃﻨﻴﺔ ﻟﻠﻌﻠﻮم ﰲ وﻗﺖ ﻻﺣﻖ ﻣـﻦ ﻫـﺬا اﻟﻌﺎم « . ﻳـﻮﻓﺮ PicII-503 ﺤـﺔ ﻧـﺎدرة وﻣﺒﺎﴍة ﻋﻦ اﻟﻔﺼﻞ اﻷول ﻣﻦ اﻟﺘﻄـﻮر اﻟﻜﻴﻤﻴﺎﺋﻲ ﻟﻠﻜﻮن، وﻫﻮ ﻟﺤﻈﺔ أﺳﺎﺳـﻴﺔ اﻟﻮﻃﻨﻴﺔ ﻟﻠﻌﻠﻮم ﰲ وﻗﺖ ﻻﺣﻖ ﻣﻦ ﻫﺬا اﻟﻌﺎم « . ﺗﻌﻤﻞ ﻓﺮق اﻟﻔﻠﻚ اﻟﺪوﻟﻴﺔ ﻋﲆ ﺗﺤﻠﻴﻞ ﺑﻴﺎﻧـﺎت اﻟﻨﺠﻢ PicII-503 ﺑﺎﺳﺘﺨﺪام ﺗﻘﻨﻴﺎت ﺣﺪﻳﺜﺔ ﺗﺠﻤﻊ ﺑ اﻟﻄﻴﻒ اﻟﻀﻮﺋﻲ وﺗ ﻠﻴﻞ اﻟﻜﻴﻤﻴـﺎء اﻟﻨﺠﻤﻴﺔ ﻣـﺎ ﻳﺘـﻴﺢ ﺗﺤﺪﻳـﺪ ﻧﺴـﺐ اﻟﻌﻨـﺎﴏ اﻟﺜﻘﻴﻠﺔ واﻟﺨﻔﻴﻔﺔ داﺧـﻞ اﻟـﻨﺠﻢ ﺑﺪﻗـﺔ ﻏـ ﻣﺴـﺒﻮﻗﺔ . ﻫــﺬه ا ﻌﻠﻮﻣـﺎت ﺗﻤـﻨﺢ اﻟﻌﻠﻤـﺎء اﻟﻘﺪرة ﻋﲆ إﻋﺎدة ﺑﻨﺎء ﺗﺎرﻳﺦ ﺗﻜﻮﻳﻦ اﻟﻨﺠـﻮم اﻷوﱃ وﻓﻬﻢ اﻟﻌﻤﻠﻴﺎت اﻟﻔﻴﺰﻳﺎﺋﻴﺔ اﻟﺘﻲ ﺳﺎدت ﰲ اﻟﻜﻮن اﻟﺒـﺪاﺋﻲ . ﻋـﻼوة ﻋـﲆ ذﻟـﻚ، ﺗﺘـﻴﺢ ا ﻘﺎرﻧﺎت ﻣﻊ ﻧﺠﻮم أﺧﺮى ﰲ ﻣﺠـﺮات ﻗﺰﻣـﺔ ﻣﺸـﺎﺑﻬﺔ ﺗﺤﺪﻳـﺪ اﻷﻧﻤـﺎط اﻟﻌﺎﻣـﺔ ﻟﺘﻄـﻮر اﻟﻌﻨﺎﴏﻋﱪ اﻟﺰﻣﻦ ا ﻟﻜﻮﻧﻲ . ﻳﻮﻓﺮ اﻟﻨﺠﻢ PicII-503 ﺤﺔ ﻧﺎدرة وﻣﺒﺎﴍة ﻋـﻦ اﻟﻔﺼـﻞ ا ﻷول ﻣـﻦ اﻟﺘﻄـﻮر اﻟﻜﻴﻤﻴـﺎﺋﻲ ﻟﻠﻜﻮن وﻫﻮ ﻟﺤﻈﺔ أﺳﺎﺳﻴﺔ ﻣﻬﺪت ﰲ اﻟﻨﻬﺎﻳﺔ ﻟﺘﺸﻜﻞ اﻟﻜﻮاﻛﺐ واﻟﻜﻴﻤﻴﺎء واﻟﺤﻴﺎة ﻧﻔﺴـﻬﺎ . ﻛﻤﺎ ﻳﺮﺑﻂ ﻫﺬا اﻻﻛﺘﺸﺎف أﻟﻐﺎز اً ﻗﺪﻳﻤﺔ ﺗﺘﻌﻠﻖ ﺑ ـﺎﻟﻨﺠﻮم اﻟﻌﺘﻴﻘــﺔ ﰲ ﻣﺠــﺮة درب اﻟﺘﺒﺎﻧــﺔ ﺑﺄﺻﻮﻟﻬﺎ ﰲ ا ﺠﺮات اﻟﻘﺰﻣﺔ اﻟﺒﺪاﺋﻴﺔ . ﺎﻣ ا اﻟﻄﺎﻗﺔ اﻟﻤﻈﻠﻤﺔ ) ﺎم د ( اﻟﻤﺼﻨﻌ ـﺔ ﻣﺜ ﺘـﺔ ﻋﻠـﻰ ﺗﻠﺴـ ﻮب ﻓ ﻜﺘـﻮر ﺔ ﻣﻦ ﻗﺒﻞ وزارة اﻟﻄﺎﻗﺔ اﻷﻣﺮ ﻜ اﻷرﻌﺔ أﻣﺘﺎرﻓﻲﻣﺮﺻﺪ ﺳ و ﺗﻮﻟﻮﻟﻮ ﻓﻲﺷﻤﺎل وﺳﻂ ﺗﺸ ﻠﻲ ﻼﻧ ﻮ ذ . [CTIO/NOIRLab/DOE/NSF/AURA/R. Hahn(Fermi National Accelerator Laboratory)] - ﻣﺎﻳﻮ ﻳﻮﻧﻴﻮ 2 0 2 6