Free Astronomy Magazine September-October 2024

F Alignment of bipolar jets confirms star formation theories byNASA/ESA/CSA BethanyDowner ChristinePulliam orthefirsttime,aphenomenon astronomers have longhoped todirectlyimagehasbeencap- turedbyNASA’sJamesWebbSpace Telescope’s Near-InfraredCamera (NIRCam).Inthisstunningimageof the Serpens Nebula, the discovery liesinthenorthernarea(seenatthe upper left) of this young, nearby star-forming region. Astronomers found an intriguing group of proto- stellar outflows, formed when jets of gas spewing from newborn stars collidewithnearbygasanddust at high speeds. Typically these ob- jectshavevariedorientationswithin one region. Here, however, they are slantedinthesamedirection,tothe same degree, like sleet pouring down during a storm. The discovery of these aligned ob- jects,madepossibleduetoWebb’s exquisite spatial resolutionand sensitivity in near-infrared wave- lengths, is providing information into the fundamentals of how stars are born. “Astronomers have long assumed that as clouds collapse to formstars,thestarswilltendtospin inthesamedirection,” saidprincipal investigator Klaus Pontoppidan, of NASA’sJetPropulsionLaboratoryin Pasadena,California. “However,this hasnotbeenseensodirectlybefore. These aligned, elongated structures are a historical record of the funda- mental way that stars are born.” So just how does the alignment of thestellarjetsrelatetotherotation ofthestar?Asaninterstellargas cloud crashes in on itself to form a star, it spins more rapidly. Theonlywayforthegastocontinue moving inward is for some of the spin(knownasangularmomentum) to be removed. A disk of material formsaroundtheyoungstartotrans- 34 إﺻــﻄﻔﺎف اﻟﻨﻔﺎﺛــﺎت ـﺔ اﻟﻘﻄـﺐ ﺛﻨﺎﺋ ﻳ ﺆﻛـﺪ ــــــــــــــــــﻮﻳﻦ ﻧﻈﺮ ــــــــــــــــــﺎت ﺗ اﻟﻨﺠﻮم : ﻘﻠﻢ ﺑ ﺜﺎﻧﻲداوﻧﺮ ﺑﻮﻟ ﺎم وﻛﺮﺴﺘ و ﺎﻟﺔ ﻧﺎﺳﺎ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑ ﺔ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻟﻜﻨﺪ ﺔ ﻷول ﻣﺮة ﻛﺎن ﻋﻠﻤﺎء ﻓﻠﻚ اﻟﻈﻮاﻫﺮ ﻳﺄﻣﻠﻮن ﻣﻨﺬ ﻓﱰة ﻃﻮﻳﻠﺔ ﰲ اﻟﺘﻘﺎط اﻟﺼﻮرة ﻣﺒﺎﴍة ﺑﻮاﺳﻄﺔ اﻟﻜﺎﻣ ا اﻟﻘﺮﻳﺒﺔ ﻣﻦ اﻷﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء ﻧ ﻛﺎم ) ( اﻟﺘﺎﺑﻌﺔ ﻟﺘﻠﺴﻜﻮبﺟﻴﻤﺲ وﻳﺐ اﻟﻔﻀﺎﺋﻲ اﻟﺘﺎﺑﻊ ﻟﻨﺎﺳﺎ . ﻳﻈﻬﺮ ﰲ ﻫـﺬه اﻟﺼﻮرة ا ﺬﻫﻠﺔ ﻟﺴﺪﻳﻢ اﻟﺜﻌﺒﺎن اﻻﻛﺘﺸـﺎف ﰲ ا ﻨﻄﻘﺔ اﻟﺸﻤﺎﻟﻴﺔ ) اﻟﺘـﻲ ﺗﻈﻬـﺮ ﰲ أ ﻋـﲆ اﻟﻴﻤ ( ﻣﻦ ﻣﻨﻄﻘﺔ ﺗﺸﻜﻞ اﻟﻨﺠﻮم اﻟﺸـﺎﺑﺔ اﻟﻘﺮﻳﺒﺔ . اﻛﺘﺸﻒ ﻋﻠﻤـﺎء اﻟﻔﻠـﻚ ﻣﺠﻤﻮﻋـﺔ ﻣﺜ ة ﻟﻼﻫﺘﻤـﺎم ﻣـﻦ اﻟﺘـﺪ ﻓﻘﺎت اﻟﻨﺠﻤﻴـﺔ اﻷوﻟﻴﺔ إﱃ اﻟﺨـﺎرج واﻟﺘـﻲ ﺗﺘﺸـﻜﻞ ﻋﻨـﺪﻣﺎ ﺗﺼﻄﺪم ﻧﻔﺎﺛﺎت اﻟﻐﺎز ا ﻨﺒﻌﺜﺔ ﻣﻦ اﻟﻨﺠـﻮم ﺣﺪﻳﺜﺔ اﻟـﻮﻻدة ﺑﺎﻟﻐـﺎز واﻟﻐﺒـﺎر اﻟﻘـﺮﻳﺒ ﺑﴪﻋﺎت ﻋﺎﻟﻴﺔ .ﺟﺪاً ﻋﺎدةً ﻣﺎ ﻳﻜـﻮن ﻟ ﻬـﺬه اﻟﻜﺎﺋﻨﺎت اﺗﺠﺎﻫﺎت ﻣﺘﻨﻮﻋﺔ داﺧـﻞ ﻣﻨﻄﻘـﺔ واﺣﺪة أﻣﺎ ﻫﻨﺎ ﻓﻬﻲ ﻣﺎﺋ ﻠﺔ ﰲ ﻧﻔﺲ اﻻﺗﺠـﺎه وﺑﻨﻔﺲ اﻟﺪرﺟﺔ ﻣﺜـﻞ اﻟﺼـﻘﻴﻊ ا ﺘﺴـﺎﻗﻂ أﺛﻨﺎء اﻟﻌﺎﺻﻔﺔ . أﺛﻨﺎء اﻟﻌﺎﺻﻔﺔ . إن اﻛﺘﺸﺎف ﻫﺬه اﻷﺟﺴـﺎم ا ﱰاﺻﻔﺔ اﻟﺬي أﺻﺒﺢ ﻣﻤﻜﻨﺎ ﺑﻔﻀـﻞ دﻗـﺔ ﺗﻠﺴﻜﻮب وﻳﺐ ا ﻜﺎﻧﻴﺔ اﻟﺮاﺋﻌﺔ وﺣﺴﺎﺳﻴﺘﻪ ﻟﻸﻃﻮال ا ﻮﺟﻴﺔ اﻟﻘﺮﻳﺒﺔ ﻣﻦ اﻷﺷﻌﺔ ﺗﺤـﺖ اﻟﺤﻤﺮاء ﻳـﻮﻓﺮ ﻣﻌﻠﻮﻣـﺎت ﻋـﻦ أﺳﺎﺳـﻴﺎت ﻛﻴﻔﻴﺔ وﻻدة اﻟﻨﺠﻮم . ﻗﺎل اﻟﺒﺎﺣﺚ اﻟﺮﺋﻴ ﴘ ـ ﻛﻼوس ﺑﻮﻧﺘﻮﺑﻴﺪان ﻣﻦ ﻣﺨﺘﱪ اﻟﺪﻓﻊ ا ﻟﻨﻔﺎث اﻟﺘﺎﺑﻊ ﻟﻨﺎﺳﺎ ﰲ ﺑﺎﺳﺎدﻳﻨﺎ، ﻛﺎﻟﻴﻔﻮرﻧﻴﺎ " : ﻟﻘـﺪ اﻓﱰض اﻟ ﻌﻠﻤﺎء ﻣﻨﺬ ﻓﱰة ﻃﻮﻳﻠﺔ أﻧﻪ ﻋﻨـﺪﻣﺎ ﺗﻨﻬﺎر اﻟﺴﺤﺐ ﻟﺘﺸﻜﻞ اﻟ ﻨﺠﻮم ﺗﻤﻴﻞ اﻟﻨﺠﻮم إﱃ اﻟﺪوران ﰲ ﻧﻔﺲ اﻻﺗﺠﺎه وﻫﺬه اﻟﻬﻴﺎﻛـﻞ ا ﱰاﺻﻔﺔ وا ﻤﺪودة ﻫـﻲ ﺳـﺠﻞ ﺗـﺎرﻳﺨﻲ ﻟﻠﻄﺮﻳﻘ ﺔ اﻷﺳﺎﺳﻴﺔ اﻟﺘﻲ ﺗﻮﻟﺪ ﺑﻬﺎ اﻟﻨﺠﻮم « . ﻓﻜﻴﻒ ﻳﺮﺗﺒﻂ اﺻﻄﻔﺎف اﻟﻨﻔﺎﺛﺎت اﻟﻨﺠﻤﻴـﺔ ﺑﺪوران اﻟﻨﺠﻢ؟ ﻋﻨﺪﻣﺎ ﺗﺼﻄﺪم ﺳﺤﺎﺑﺔ اﻟﻐﺎز ﺑـ اﻟﻨﺠـﻮم وﺗﻨﻬﺎر ﻋﲆ ﻧﻔﺴﻬ ﺎ ﻟﺘﻜـﻮﻳﻦ ﻧﺠﻤـ ﺎ ﻓﺈﻧﻬـﺎ ﺗﺪور ــــــ ﺗﺪور ﺣﻮل ﻧﻔﺴﻬﺎ ـﺑﺴ ﺮﻋﺔ أﻛﱪ و اﻟﻄﺮﻳﻘﺔ اﻟﻮﺣﻴ ـﺪة ﻻﺳــﺘﻤﺮار اﻟﻐ ـﺎز ﰲ اﻟﺘﺤ ـﺮك إﱃ اﻟﺪاﺧﻞ ﻫﻲ إزاﻟﺔ ﺑﻌﺾ اﻟﺪوران ) ا ﻌـﺮوف ﺑﺎﻟﺰﺧﻢ اﻟﺰاوي .( ﻳﺘﺸﻜﻞ ﻗﺮص ﻣﻦ ا ﻮاد ﺣـﻮل ذﻟـﻚ اﻟـﻨﺠﻢ اﻟﺸﺎب ﻟﻨﻘﻞ ا ﻮاد إﱃ ا ﻷﺳﻔﻞ ﻣﺜﻞ اﻟﺪواﻣـﺔ ا ﴫـف . وﺗﻄﻠـﻖ ا ﺠـﺎﻻت ا ﻐﻨﺎﻃﻴﺴـﻴﺔ - ﺳﺒﺘﻤﺒﺮ ﺃﻛﺘﻮﺑﺮ 2 0 2 4