Free Astronomy Magazine November-December 2025 ARABIC VERSION

away in the outer reaches of our galaxy. The Webb discovery was serendipitous. “We didn’t really know there was a massive star with this kind of super-jet out there be- fore the observation. Such a spec- tacular outflow of molecular hy- drogenfromamassivestarisrarein other regions of our galaxy,” said lead author Yu Cheng of the Na- tional Astronomical Observatory of Japan. This unique class of stellar fireworks are highly collimated jets of plasma shooting out from newly forming stars. Such jetted outflows are a star’s spectacular “birth an- nouncement” to the universe. Someoftheinfallinggasbuilding up around the central star is blasted alongthestar’sspinaxis,likelyunderth einfluenceofmagneticfields.Today,w hilehundredsofpro- tostellar jets have been observed,thesearemainlyfromlow- massstars.Thesespindle-likejetsoffer clues into the nature of newly form- ingstars.Theenergetics,narrow- ness,andevolutionarytimescalesof protostellarjetsallservetocon- strainmodelsoftheenvironment andphysicalpropertiesoftheyoungstar poweringtheoutflow. “I was really surprised at the order, symmetry, and size of the jet when wefirstlookedatit,” saidco-author Jonathan Tan of the University ofVirginia in Charlottesville and Chalmers University of Technologyin Gothenburg, Sweden. Its detec- tion offers evidence that protostel- lar jets must scale up with the mass of the star powering them. The more massive the stellar engine propelling the plasma, the largerthe gusher’s size. The jet’s detailed filamentary structure, captured by Webb’scrispresolutionininfrared light, is evidence the jet is plowing into interstellar dust and gas. This creates separate knots, bow shocks, andlinearchains.Thetipsofthejet, lying in opposite directions, encap- sulate the history of the star’s for- mation. “Originallythematerialwas closeintothestar,butover100,000 years the tips were propagatingout, and then the stuff behind is a younger outflow,” said Tan. At nearly twice the distance from the galactic center as our Sun, the host proto-cluster that’s home to the vo- raciousjetisontheperipheryofour Milky Way galaxy. Within the clus- ter, a few hundred stars are still form ing. Being in the galactic hin- terlands means the stars are defi- cient in heavier elements beyond hydrogen and helium. This is meas- ured as metallicity, which gradually increases over cosmic time as each passing stellar generation expelsend products of nuclear fusion through winds and supernovae. The lowmetallicityofSh2-284isareflec- tion of its relatively pristine nature, making it a local analog for the en- vironments in the early universethat were also deficient in heavier elements. “Massive stars, like the one found inside this cluster, have very important influences on the evolution of galaxies. Our discovery is shedding light on the formation mechanism of massive stars in low metallicity environments, so we can use this massive star as a laboratory to study what was going on in ear- lier cosmic history,” said Cheng. Stellar jets, which are powered by the gravitational energy released as a star grows in mass, encode the formation history of the protostar. “Webb’s new images are telling us thattheformationofmassivestars NOVEMBER-DECEMBER2025 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 17 ﻗﺎل ﻳﻮ ﺗﺸﻨﻎ اﻟﺒﺎﺣﺚ ـ اﻟﺮﺋ ﻴﴘ ﻣـﻦ ا ﺮﺻـﺪ اﻟﻔﻠﻜﻲ اﻟﻮﻃﻨﻲ اﻟﻴﺎﺑـﺎﻧﻲ " : ﻟـﻢ ﻧﻜـﻦ ﻧﻌﻠـﻢ ﺑ ﻮﺟﻮد ﻧﺠﻢ ﺿﺨﻢ ﻳﻄﻠـﻖ ﻧﻔﺎﺛـﺎت ﻋﻤﻼﻗـﺔ ﻛﻬﺬه اﻟﺮﺻﺪ ﻫﺬا ﻗﺒﻞ ﻳﻌﺪو ﻫﺬا اﻟﺘﺪﻓﻖ ا ﺬﻫﻞ ﻟﻠ ﻬﻴﺪروﺟ اﻟﺠﺰﻳﺌﻲ ﻣﻦ ﻧﺠـﻢ ﺿـﺨﻢ أﻣـﺮ اً اً ﻧﺎدر ﰲ ﻣﺠﺮﺗﻨﺎ ." ﻫﺬه اﻟﻔﺌـﺔ اﻟﻔﺮﻳـﺪة ﻣـﻦ اﻟﻈـﻮاﻫﺮ ﺗﻌـﺮف ﺑﺎﻟ ﻨﻔﺎﺛﺎت اﻟﻨﺠﻤﻴـﺔ اﻷوﻟﻴـﺔ وﻫـﻲ ﺗـﺪﻓﻘﺎ ت ﺑﻼزﻣﺎ ﻋﺎﻟﻴﺔ اﻟﺘﻮازي ﺗﻨ ﺒﻌﺚ ﻣﻦ ﻧﺠﻮم ﻓﺘﻴـﺔ ﰲ ﻃﻮر اﻟﺘﻜﻮّن و ﺗﻌﺪ ﺑﻤﺜﺎﺑﺔ " إﻋـﻼن ﻣـﻴﻼد " اﺳﺘﺜﻨﺎﺋﻲ ﻟﻨﺠﻢ . ﺟﺪﻳﺪ ﻳﻨـﺪﻓﻊ ﺟــﺰء ﻣـﻦ اﻟﻐـﺎز اﻟﻐـﺎز ا ﺘﺴـﺎﻗﻂ و ا ﱰاﻛﻢ ﺣـﻮل اﻟـ ﻨﺠﻢ ا ﺮﻛـﺰي ﻋـﲆ ﻃـﻮل ﻣﺤـﻮر دوراﻧـﻪ ﻋـﲆ اﻷرﺟـﺢ ﺗﺤـﺖ ﺘـﺄ ﺑ ﺛ اﻟﺤﻘﻮل ا ﻐﻨﺎﻃﻴﺴﻴﺔ اﻟﻘﻮﻳﺔ . وﺣﺘـﻰ اﻟﻴـﻮم رﺻــﺪت ﻣﺌــﺎت اﻟﻨﻔﺎﺛــﺎت اﻟﻨﺠﻤﻴــﺔ إﻻ أن ﻣﻌﻈﻤﻬﺎ ﻣﻦ ﻧﺠﻮ م ﻣﻨﺨﻔﻀـﺔ اﻟﻜﺘﻠـﺔ ﻣﻤـﺎ ﻳﺠﻌﻞ ﻫﺬا اﻻﻛﺘﺸـﺎف ﺣﺎﻟـﺔ ﻧـﺎدرة ﻟﻨﺠـﻮم ﺿﺨﻤﺔ ﻗﻴﺪ اﻟﺘﺸﻜﻞ . ﺗُﻘـﺪم ﻫـﺬه اﻟﻨﻔ ﺎﺛـﺎت اﻟﺸﺒﻴﻬﺔ ﺑﺎ ﻐﺰل أدﻟـﺔ ﻣﻬﻤـﺔ ﺣـﻮل اﻟﺒﻴﺌـﺔ ﺼواﻟﺨ ﺎﺋﺺ اﻟﻔﻴﺰﻳﺎﺋﻴﺔ ﻟﻠـﻨﺠﻢ اﻟﻮﻟﻴـﺪ اﻟـﺬي ﻳﻐﺬي اﻟﺘﺪﻓﻖ اﻟﺨﺎرﺟﻲ . ﻗﺎل ا ﺆﻟﻒ ا ﺸﺎرك ﺟﻮﻧﺎﺛﺎن ﺗﺎن ﻣﻦ ﺟﺎﻣﻌﺔ ﻓ ﺟﻴﻨﻴﺎ ﰲ ﺷﺎرﻟﻮﺗﺴﻔﻴﻞ وﺟﺎﻣﻌﺔ ﺗﺸـﺎ ﺮز ﻟﻠﺘﻜﻨﻮﻟﻮﺟ ﻴ ـﺎ ﰲ ﻏــﻮﺗﻨﱪغ اﻟﺴــﻮﻳﺪ " : ﻟﻘــﺪ ﻓﻮﺟﺌﺖ ﺣﻘ ﺎً ﺑﺎﻟﻨﻈﺎم واﻟﺘﻤﺎﺛﻞ وﺣﺠﻢ اﻟﻨﻔ ﺎﺛﺔ ﻋﻨﺪﻣﺎ ﻧﻈﺮﻧﺎ إﻟﻴﻬـﺎ أول ﻣـﺮة ." ﻳﺸـ ﻫـﺬا اﻻﻛﺘﺸﺎف إﱃ أن اﻟﻨﻔﺎﺛـﺎت اﻟﻨﺠﻤﻴـﺔ اﻷوﻟﻴـﺔ ﺗﺰداد ﻗﻮة واﺗﺴﺎﻋﺎً ﻣﻊ ﻛﺘﻠﺔ اﻟـﻨﺠﻢ ا ﺤـﺮك . ﻟﻬﺎ ﻛﻠﻤﺎ زاد ت ﻛﺘﻠ ﺔ ا ﺤﺮك اﻟﻨﺠﻤﻲ اﻟـﺪاﻓﻊ ﻟﻠﺒﻼزﻣـﺎ زاد ﺣﺠــﻢ اﻟﺪﻓﻘـﺔ . ﺗﻈﻬـﺮ اﻟﺒﻨﻴـﺔ اﻟﺸﻌﺮﻳﺔا ﻔﺼــﻠﺔ ﻟﻠﻨﻔﺎﺛ ـﺔ اﻟﺘ ـﻲ اﻟﺘﻘﻄﻬ ـﺎ ﺗﻠﺴﻜﻮب ﺟﻴﻤﺲ وﻳﺐ ﺑﺪﻗﺔ ﻋﺎﻟﻴـﺔ ﰲ ﺿـﻮء اﻷﺷـﻌﺔ ﺗﺤــﺖ اﻟﺤﻤــﺮاء ﻋﻘـﻮداً ﻣﻨﻔﺼـﻠﺔ وﺻﺪﻣﺎت ﻗﻮﺳﻴﺔ وﺳﻼﺳﻞ ﺧﻄﻴﺔ وﻫﻲ آﺛﺎر ﺗﺠﺴﺪ ﺗﺎرﻳﺦ ﺗﺸﻜﻞ اﻟﻨﺠﻢ . ﺗﻤﺘﺪ اﻃﺮاف اﻟﻨﻔﺎﺛﺔ ﰲ اﺗﺠﺎﻫ ﻣ ﺘﻌﺎﻛﺴـ ﻟﺘﺴﺠﻞ ﻣﺮاﺣﻞ وﻻدة ﻫﺬا اﻟﻨﺠﻢ اﻟﻌﻤﻼق . : " ﺗﺎن ﻗﺎل ﰲ اﻷﺻﻞ ﻛﺎﻧﺖ ا ـﺎدة ﻗﺮﻳﺒـﺔ ﻣـﻦ اﻟﻨﺠﻢ وﻟﻜﻦ ﻋﲆ ﻣـﺪار 100.00 ﻋـﺎم ﻛﺎﻧـﺖ اﻷﻃﺮاف ﺗﻨﺘﴩ ﻟﻠﺨـﺎرج، ﺛـﻢ ﺗﻜـﻮن ا ـﺎدة اﻟﻨﺠﻢ وﻟﻜ ﻦ ﻋﲆ ﻣﺪار ﻧﺤـﻮ 100 أﻟـﻒ ﻋـﺎم ﺑﺪأت أﻃﺮاف اﻟﻨﻔﺎﺛﺔ ﺑﺎﻟﺘﻤـﺪد ﻧﺤـﻮ ا ﻟﺨـﺎرج ﺑﻴﻨﻤﺎ ﺷﻜﻠﺖ ا ﺎدة ﺧﻠﻔﻬﺎ ﺗﺪﻓﻘًﺎ أﺣﺪث ." ﻳﻘﻊ اﻟﻌﻨ ﻘﻮد اﻟﻨﺠﻤـﻲ اﻷوﱄ ا ﻀـﻴﻒ ﻟﻬـﺬه اﻟﻨﻔ ﺛﺔ ﺎ اﻟﻌﻤﻼﻗﺔ ﻋﲆ ﺑﻌـﺪ ﻳﻘـﺎرب ﺿـﻌﻔﻲ ا ﺴﺎﻓﺔ ﺑـ اﻟﺸـﻤﺲ وﻣﺮﻛـﺰ ﻣﺠـﺮة درب اﻟﺘﺒﺎﻧﺔ أي ﰲ اﻷﻃﺮاف اﻟ ﺨﺎرﺟﻴﺔ ﻣـﻦ ا ﺠـﺮة ﻻ ﺗﺰال ﺣﻴﺚ ﺑﻀـﻊ ﻣﺌـﺎت اﻟﻨﺠـﻮم ﰲ ﻃـﻮر اﻟﺘﺸﻜﻞ . ﻫﺬه ﰲ ﻳﻮﺟﺪ ا ﻨﺎﻃﻖ اﻟ ﺒﻌﻴـﺪة ﻣـﻦ ا ﺠﺮة ﺗﻜﻮن اﻟﻨﺠﻮم ﻓﻘ ة ﺑﺎﻟﻌﻨﺎﴏ اﻟﺜﻘﻴﻠﺔ ) أي ﻣﻨﺨﻔﻀـﺔ ا ﻌﺪﻧﻴ ـﺔ ( ﻟﻨـﺪرة اﻟﻌﻨ ـﺎﴏ اﻷﺛﻘﻞ ﻣﻦ اﻟﻬﻴﺪروﺟ واﻟﻬﻠﻴﻮم . ﻳﻘﺎس ذﻟﻚ ﺑﻤﺎ ﻳﻌـﺮف ﺑﻤﻌﺪﻧﻴـﺔ اﻟﻨﺠـﻮم وﻫـﻲ ﻧﺴـﺒﺔ اﻟﻌﻨﺎﴏ اﻷﺛﻘﻞ اﻟﺘ ﺗﺘﺰاﻳﺪ ﻲ ﺗﺪرﻳﺠﻴ ﺎً ﻣﻊ ﻣﺮور اﻟﺰﻣﻦ اﻟﻜﻮﻧﻲ إذ ﺗﺜﺮي اﻷﺟﻴﺎل ا ﻌﺎﻗﺒـﺔ ﻣـﻦ اﻟﻨﺠﻮم اﻟﻮﺳﻂ اﻟﺒﻴﻨﺠﻤﻲ ﻋﱪ ﻣﺎ ﺗﻄﺮده ﻣـﻦ ﻣﻮاد أﺛﻨـﺎء ﻣﺮاﺣﻠﻬـﺎ اﻷﺧـ ة ﻣﺜـﻞ اﻟﺮﻳـﺎح اﻟﻨﺠﻤﻴﺔ وا ﺴﺘﻌﺮات اﻟﻌﻈﻤﻰ . ﻳﻌﻜﺲ اﻧﺨﻔﺎض ﻣﻌﺪﻧ ﺔﻴ Sh2-284 ﻃﺒﻴﻌﺘﻪ اﻟﻨﻘﻴﺔ ﻧﺴﺒﻴ ﺎً ﻣﻤﺎ ﻳﺠﻌﻠﻪ ﻧﻈ اً ﺎً ﻣﺤﻠﻴ ﻟﺒﻴﺌﺎت اﻟﻜﻮن ا ﺒﻜﺮ اﻟﺘﻲ ﻛﺎﻧﺖ ﺗﻌﺎﻧﻲ ﻣﻦ ﻧﻘـﺺ ﰲ اﻟﻌﻨﺎﴏ اﻷﺛﻘﻞ . ﻗﺎل ﺗﺸﻨﻎ " : إن اﻟﻨﺠﻮم اﻟﻀﺨﻤﺔ ﻣﺜـ ﻞ ﺗﻠـﻚ ا ﻮﺟﻮدة داﺧﻞ ﻫﺬا اﻟﻌﻨﻘﻮد ﺗﺆدي دورا ﺑـﺎﻟﻎ اﻷﻫﻤﻴﺔ ﰲ ﺗﻄﻮر ا ﺠﺮات وﻳﺴﻠﻂ اﻛﺘﺸـﺎﻓﻨﺎ اﻟﻀﻮء ﻋﲆ آﻟﻴﺔ ﺗﻜﻮﻳﻦ اﻟﻨﺠـﻮ م اﻟﻀـﺨﻤﺔ ﰲ اﻟ ﺒﻴﺌﺎت ﻣﻨﺨﻔﻀﺔ ا ﻌﺪن ﻣﺎ ﻳ ﺘﻴﺢ اﺳـﺘﺨﺪام ﻫﺬا اﻟﻨﺠﻢ ﻛﻤﺨﺘ ﱪ ﻟﺪراﺳﺔ اﻟﻌﻤﻠﻴـﺎت اﻟﺘـﻲ ﻛﺎﻧﺖ ﺗﺤﺪث ﰲ اﻟﺘﺎرﻳﺦ اﻟﻜﻮﻧﻲ ا ﺒﻜﺮ . ﻛﻤﺎ أن اﻟﻨﻔ ﺎ ﺛﺎت اﻟﻨﺠﻤﻴﺔ اﻟﺘﻲ ﺑﻔ ﺗﻨﺸﺎ ﻌﻞ اﻟﺠﺎذﺑﻴـﺔ أﺛﻨﺎء ﺗﺮاﻛﻢ ﻛﺘﻠﺔ اﻟﻨﺠﻢ ﺗﺤﻤـﻞ أدﻟـﺔ ﺧﻔﻴـﺔ ﺗﻜﺸﻒ ﻛﻴﻒ ﺑﺪأ اﻟﻨﺠﻢ رﺣﻠﺘﻪ ﻧﺤﻮ اﻟﺘﻜﻮّن ". وﴏح ﺗﺎن ﺗ : " ﺸ ﺻـﻮر ﺗﻠﺴـﻜ ﻳـﺐ ب و ﻮ اﻟﺠﺪﻳﺪة إﱃ أن ﺗﻜﻮ ن اﻟﻨﺠﻮم اﻟﻀﺨﻤﺔ ﰲ ﻣ ﺜﻞ ﻫﺬه اﻟ ﺒﻴﺌﺎت ﻗﺪ ﻳﺘﻢ ﻋﱪ ﻗﺮصﻣﺴﺘﻘﺮ ﻧﺴﺒﻴ ﺎً ﺣﻮل اﻟﻨﺠﻢ وﻫﻮ ﻣﺎ ﺗﺘﻨﺒﺄ ﺑﻪ اﻟﻨﻤﺎذج اﻟﻨﻈﺮﻳﺔ ﻟﺘﻜﻮّ ن اﻟﻨﺠﻮم وا ﻌﺮوف ﺑﺎﺳﻢ ﺗﺮاﻛﻢ اﻟ ﻠﺐ ." وأﺿﺎف " : ﺑﻤﺠﺮد أن وﺟـﺪﻧﺎ ﻧﺠﻤـ ﺎً ﺿـﺨﻤﺎً أ ﻃﻠـﻖ ﻫـﺬه اﻟﻨﻔ ﺎ ﺛـﺎت أدرﻛﻨـﺎ أﻧـﻪ ﻳ ﻤﻜﻨﻨـﺎ اﺳـﺘﺨﺪام أرﺻـﺎد ﺗﻠﺴـﻜﻮب وﻳـﺐ ﻻﺧﺘﺒـﺎر ﻧﻈﺮﻳﺎت ﺗ ﺸﻤﻞ اﻟﻨﺠﻮم اﻟﻀﺨﻤﺔ وﻗﺪ ﻃﻮرﻧـﺎ ﻧﻮﻓﻤﺒﺮ - ﺩﻳﺴﻤﺒﺮ 2 0 2 5 ﺗﻘﺪم ﺻﻮرة ﺗﻠﺴ ﻮبﺟ ﻤﺲ و ﺐ ﻟﻠﻨ ﻢ اﻟﻨﻔﺎث اﻟﻬﺎﺋﻞ h2-284 دﻟ ﻼً ﻋﻠﻰ أن اﻟﻨﻔﺎﺛﺎت اﻟﻨ ﻤ ﺔ اﻷوﻟ ﺔ ﺗﺘﻨﺎﺳﺐ ﻣ ﻊ ﻛﺘﻠﺔ اﻟﻨﺠﻮم ﻏ اﻷﺻﻠ ﺔ ﻓ ﻠﻤﺎ زادت ﻛﺘﻠﺔ اﻟﻨ ﻢ اﻟﻤﺤﺮك ﻟﻠ ﻼزﻣﺎ زادت اﻟﻨﻔﺎﺛﺎت اﻟﻨﺎﺗﺠﺔ وﻫﺬا ﻋﻠﻰﻓﻬﻢ أﻓﻀﻞ ﻵﻟ ﺎت ﺗﺸ ﻞ اﻟﻨﺠﻮم وﺗﺄﺛ اﺗﻬﺎ ﻋﻠﻰ اﻟﺒﻴﺌﺔ اﻟﻤﺤ ﻄﺔ ﺑﻬﺎ ﺴﺎﻋﺪ اﻟﻔﻠﻜﻴ . [Image:NASA,ESA,CSA,STScI,YuCheng(NAOJ);Image Processing:J.DePasquale (STScI)]