Free Astronomy Magazine January-February 2023 ARABIC VERSION

N dust, the less blue light is able to es- cape, creating pockets of orange. Webb also reveals filaments of mo- lecular hydrogen that have been shocked as the protostar ejects ma- terial away from it. Shocks and tur- bulence inhibit the formation of new stars, which would otherwise form all throughout the cloud. As a result, the protostar dominates the space, taking much of the material for itself. Despite the chaos that L1527 causes, it’s only about 100,000 years old - a relatively young body. Given its age and its brightness in far-infrared light as observed by missions like the Infrared Astronomical Satellite, L1527 is considered a class 0 proto- star, the earliest stage of star forma- tion. Protostars like these, which are still cocooned in a dark cloud of dust and gas, have a long way to go be- fore they become full-fledged stars. L1527 doesn’t generate its own en- ergy through nuclear fusion of hy- drogen yet, an essential character- istic of stars. Its shape, while mostly spherical, is also unstable, taking the form of a small, hot, and puffy clump of gas somewhere between 20 and 40% the mass of our Sun. As the protostar continues to gather mass, its core gradually compresses and gets closer to stable nuclear fu- sion. The scene shown in this image reveals L1527 doing just that. The surrounding molecular cloud is made up of dense dust and gas being drawn to the center, where the protostar resides. As the mate- rial falls in, it spirals around the cen- ter. This creates a dense disk of material, known as an accretion disk, which feeds material to the protostar. As it gains more mass and compresses further, the tempera- ture of its core will rise, eventually reaching the threshold for nuclear fusion to begin. The disk, seen in the image as a dark band in front of the bright center, is about the size of our solar system. Given the density, it’s not unusual for much of this material to clump together - the beginnings of plan- ets. Ultimately, this view of L1527 provides a window into what our Sun and solar system looked like in their infancy.    JANUARY-FEBRUARY 2023 ﻣﺠﻠﺔ Astronomy ﺎﻟﻌﺮ ﺔ ٣٦ ﻣﻨﻈﺮﺟﺪ ﺪ ﻟ ﻠﺴﺤﺎ ﺔ اﻟﻤﻈﻠﻤﺔ L1527 : ﻘﻠﻢ ﻣﺎﺛﻴﻮ ﺑﺮاون و ﺑﻮﻟ ﺎم ﻛﺮﺴﺘ و ﺎﻟﺔ ﻧﺎﺳﺎ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑ ﺔ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻟﻜﻨﺪ ﺔ ﺗﻠﺴﻜﻮب ﺟﻴﻤﺲ وﻳﺐ اﻟﻔﻀـﺎﺋﻲ اﻟﺘﺎﺑﻊ ﻟﻮﻛﺎﻟﺔ ﻧﺎﺳﺎ ﻋﻦ أﺷﻜﺎل ﺘ ﻛﺎﻧﺖ ﻣ ﺨﻔﻴﺔ ﻟﻠﻨﺠﻢ اﻷوﱄ داﺧﻞ اﻟﺴﺤﺎﺑﺔ ا ﻈﻠﻤـﺔ L1527 ﻣﻤﺎ ﻳﻮﻓﺮ ﻧﻈﺮة ﺛﺎﻗﺒﺔ ﻟﺒـﺪاﻳﺎت ﻧﺠـﻢ ﺟﺪﻳـﺪ ﻫﺬه اﻟﻐﻴﻮم ا ﺘﻮﻫﺠﺔ داﺧﻞ ﻣﻨﻄﻘـﺔ ﺗﺸـﻜﻞ اﻟﻨﺠﻮم ﰲ ﻛﻮﻛﺒﺔ اﻟﺜﻮر ﻣﺮﺋﻴﺔ ﻓﻘﻂ ﰲ ﺿـﻮء اﻷﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤـﺮاء ﻣﻤـﺎ ﻳﺠﻌﻠﻬـﺎ ﻫـﺪﻓًﺎ ﻣﺜﺎﻟﻴًﺎ ﻟﻜﺎﻣ ا وﻳﺐ اﻟﻘﺮﻳﺒﺔ ﻣﻦ اﻷﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء ) ﻧ ﻛـﺎم .( إن اﻟـﻨﺠﻢ اﻷوﱄ ﻧﻔﺴـﻪ ﻣﺘﺨﻔﻴﺎً ﻋﻦ اﻷﻧﻈﺎر داﺧﻞ " ﻋﻨﻖ" ﻫﺬا اﻟﺸﻜﻞ اﻟﺰﺟﺎﺟﻲ ﻋﲆ ﺷﻜﻞ ﺳﺎﻋﺔ . رﻣﻠﻴـﺔ ﻳُﻨﻈـﺮ إﱃ اﻟﻘﺮص اﻟﻜﻮﻛﺒﻲ اﻷوﱄ ﻋﲆ اﻟﺤﺎﻓﺔ ﻋـﲆ أﻧـﻪ ﺧﻂ ﻣﻈﻠﻢ ﻳﻤﺘـﺪ ﻋـﱪ ﻣﻨﺘﺼـﻒ اﻟﻌﻨـﻖ ان . اﻟﻀﻮء ﻳﺘﴪب ﻣـﻦ اﻟـﻨﺠﻢ اﻷوﱄ ﻓـﻮق ﻫـﺬا اﻟﻘﺮص وﺗﺤﺘﻪ ﻣﻤﺎ ﻳﴤء اﻟﺘﺠـﺎوﻳﻒ داﺧـﻞ اﻟﻐﺎز واﻟﻐﺒﺎر ا ﺤﻴﻄ أ . ﻛﺜﺮ ا ﻴﺰات اﻧﺘﺸﺎرًاً ، ﰲ ا ﻨﻄﻘﺔ اﻟﻐﻴﻮم ا ﻠﻮﻧﺔ ﺑﺎﻷزرق واﻟﱪﺗﻘـﺎﱄ ﰲ ﻫــﺬه اﻟﺼــﻮرة ذات اﻷﻟــﻮان اﻟﺘﻤﺜﻴﻠﻴــﺔ ﺑﺎﻷﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء ﺗﺤﺪد اﻟﺘﺠﺎوﻳﻒ اﻟﺘﻲ ﺗ ﻢ إﻧﺸﺎؤﻫﺎ ﻋﻨﺪﻣﺎ ﺗﻨﻄﻠﻖ ا ـﺎدة ﺑﻌﻴـﺪًا ﻋـﻦ اﻟﻨﺠﻢ اﻷوﱄ وﺗﺘﺼﺎدم ﻣـﻊ ا ـﺎدة ا ﺤﻴﻄـﺔ . ﺗﺮﺟﻊ اﻷﻟﻮان ﻧﻔﺴﻬﺎ إﱃ ﻃﺒﻘﺎت اﻟﻐﺒﺎر ﺑـ ﺗﻠﺴﻜﻮب وﻳﺐ واﻟﻐﻴﻮم . ا ﻨﺎﻃﻖ اﻟﺰرﻗﺎء ﻫﻲ اﻟﺘﻲ ﻳﻜﻮن اﻟﻐﺒﺎر ﻓﻴﻬﺎ أﻗـﻞ ﺳـﻤﺎﻛﺔ ﻛﻠﻤـﺎ و ــــــــ ﻛﺎﻧﺖ ﻃﺒﻘﺔ اﻟﻐﺒﺎر أﻛﺜﺮ ﺳـﻤﻜًﺎ ﻗـﻞ اﻟﻀـﻮء اﻷزرق اﻟﻘﺎدر ﻋـﲆ اﻟﻬـﺮوب ﻣﻤـﺎ ﻳـﺆدي إﱃ ﺗﻜﻮﻳﻦ ﺟﻴﻮب ﺑﺮﺗﻘﺎﻟﻴـﺔ . ﻳﻜﺸـﻒ ﺗﻠﺴـﻜﻮب وﻳﺐ أﻳﻀًﺎ ﻋﻦ ﺧﻴﻮط اﻟﻬﻴﺪ روﺟ اﻟﺠﺰﻳﺌـﻲ اﻟﺘﻲ ﺻُﺪﻣﺖ ﻋﻨﺪﻣﺎ ﻗﺬف اﻟـﻨﺠﻢ اﻷوﱄ ا ـﻮاد ﺑﻌﻴﺪًا ﻋﻨﻪ ﺗﻤﻨـﻊ اﻟﺼـﺪﻣﺎت واﻻ ﺿـﻄﺮاﺑﺎت ﺗﻜﻮن اﻟﻨﺠﻮم اﻟﺠﺪﻳﺪة واﻟﺘﻲ ﻛﺎﻧﺖ ﺳﺘﺘﺸﻜﻞ ﰲ ﺟﻤﻴﻊ أﻧﺤﺎء اﻟﺴﺤﺎﺑﺔ . ﻧﺘﻴﺠﺔ ﻟﺬﻟﻚ ﻳﻬﻴﻤﻦ اﻟﻨﺠ ﻢ اﻷوﱄ ﻋﲆ اﻟﻔﻀﺎء وﻳﺄﺧﺬ اﻟﻜﺜـ ﻣـﻦ ا ﻮاد ﻟﻨﻔﺴﻪ ﻋﲆ اﻟﺮﻏﻢ ﻣـﻦ اﻟﻔـﻮﴇ اﻟﺘـﻲ ﻳﺴﺒﺒﻬﻪ اﻟﻨﺠﻢ L1527 ﻳﺒﻠـﻎ ﻋﻤـﺮه ﺣـﻮاﱄ ١٠٠٠٠٠ ﻋﺎم ﻓﻘﻂ ﺟﺴﻢ ﻳﺎﻓﻊ ﻧﺴﺒﻴًﺎ . ﻧﻈﺮًا ﻟﻌﻤـﺮه وﺳـﻄﻮﻋﻪ ﰲ ﺿـﻮء اﻷﺷـﻌﺔ ﺗﺤـﺖ اﻟﺤﻤﺮاء اﻟﺒﻌﻴﺪة ﻛﻤـﺎ ﺗﻤـﺖ ﻣﻼﺣﻈﺘـﻪ ﻣـﻦ ﺑﻌﺜﺎت ﻋﺪة ﺧﻼل اﺳﺘﻜﺸـﺎﻓﻴﺔ ﻣﺜـﻞ اﻟﻘﻤـﺮ اﻟﺼﻨﺎﻋ ﻲ اﻟﻔﻠﻜﻲ ﺗﺤﺖ اﻷﺣﻤﺮ ﻳﻌﺘﱪ L1527 اﻟ ﻣﻦ ﻣﻦ( ﺻﻔﺮ ) ﻔﺌﺔ اﻟﻨﺠﻮم اﻷوﻟﻴـﺔ وﻫـﻲ ا ﺮﺣﻠﺔ اﻷوﱃ ﻣﻦ ﺗﻜﻮﻳﻦ اﻟﻨﺠﻮم . إن اﻟﻨﺠـﻮم اﻷوﻟﻴــﺔ ﻣﺜـﻞ ﻫـﺬه اﻟﺘـﻲ ﻻ ﺗـﺰال ﻣﺤﺎﻃـﺔ ﺑﺴﺤﺎﺑﺔ ﻣﻈﻠﻤﺔ ﻣﻦ اﻟﻐﺒـﺎر واﻟﻐـﺎ ز ﻻ ﻳـﺰال أﻣﺎﻣﻬﺎ ﻃﺮﻳﻖ ﻃﻮﻳﻞ ﻟﺘﻘﻄﻌﻪ ﻗﺒﻞ أن ﺗﺼﺒﺢ ﻧﺠﻮﻣﺎ ﻣﻜﺘﻤﻠﺔ اﻟﻨﻤﻮ . ﻻ ﻳﻮﻟﺪ اﻟـﻨﺠﻢ L1527 ﻃﺎﻗﺘﻪ اﻟﺨﺎﺻﺔ ﻣﻦ ﺧﻼل اﻻﻧـﺪ ﻣﺎج اﻟﻨـﻮوي ﻟﻠﻬﻴــﺪروﺟ ﺣﺘــﻰ اﻵن وﻫــﻲ ﺧﺎﺻــﻴﺔ ـــــــــــــ أﺳﺎﺳﻴﺔ ﻟﻠﻨﺠﻮم ﻋﲆ اﻟـﺮﻏﻢ ﻣـﻦ أن ﺷـﻜﻠﻪ ﻛﺮوي ﰲ اﻟﻐﺎﻟﺐ إﻻ أﻧﻪ ﻏـ ﻣﺴـﺘﻘﺮ أﻳﻀًـﺎ ﺣﻴﺚ ﻳﺘﺨﺬ ﺷـﻜﻞ ﻛﺘﻠـﺔ ﺻـﻐ ة وﺳـﺎﺧﻨﺔ وﻣﻨﺘﻔﺨﺔ ﻣﻦ اﻟﻐﺎز ﻣـﺎ ﺑـ ٢٠ و ٤٠ ٪ ﻣـﻦ ﻛﺘﻠﺔ اﻟﺸﻤﺲ ﻣـﻊ اﺳـﺘﻤﺮ ار اﻟـﻨ ﺠﻢ اﻷوﱄ ﰲ ﺗﺠﻤﻴﻊ ﻛﺘﻠﺘﻪ ﻳﻨﻀﻐﻂ ﻗﻠﺒﻪ ﺗﺪرﻳﺠﻴﺎً وﻳﻘﱰب ﻣﻦ اﻧﺪﻣﺎج ﻧﻮوي ﻣﺴـﺘﻘﺮ . ﻳﻮﺿـﺢ ا ﺸـﻬﺪ ا ﻮﺿﺢ ﰲ ﻫـﺬه اﻟﺼـﻮرة أن اﻟـﻨﺠﻢ L1527 ﻳﻔﻌ ـﻞ ذﻟ ـﻚ ﺑﺎﻟﻀ ـﺒﻂ . ﺗﺘﻜ ـﻮن اﻟﺴ ـﺤﺎﺑﺔ اﻟﺠﺰﻳﺌﻴﺔ ا ﺤﻴﻄﺔ ﻣﻦ ﻏﺒﺎر ﻛﺜﻴﻒ وﻏﺎز ﻳـﺘﻢ ﺳﺤﺒﻬﻤﺎ إﱃ ا ﺮﻛﺰ ﺣﻴﺚ ﻳﻮﺟﺪ ا ﻟـﻨﺠﻢ اﻷوﱄ . ﻋﻨﺪﻣﺎ ﺗﺴﻘﻂ ا ﺎدة ﺗﺪور ﻳﻨﺘﺞ و ﺣﻮل ا ﺮﻛﺰ ﻋﻦ ﻫﺬا ﻗﺮص ﻛﺜﻴﻒ ﻣﻦ ا ﻮاد ﻳُﻌﺮف ﺑﺎﺳـﻢ " ﻗﺮص اﻟﱰاﻛﻢ اﻟـﺬي ﻫﻮ و " ﻳﻐـﺬي ا ـﺎدة إﱃ اﻟﻨﺠﻢ اﻷوﱄ و ﻣﻊ اﻛﺘﺴﺎب ا ﺰﻳﺪ ﻣـﻦ اﻟﻜﺘﻠـﺔ واﻟﻀﻐﻂ أﻛﺜﺮ ﺳﱰﺗﻔﻊ درﺟـﺔ ﺣـﺮارة ﻟﺒﻬـﺎ ﻟﺘﺼـﻞ ﰲ اﻟﻨﻬﺎﻳ ـﺔ إﱃ ﻋﺘﺒ ـﺔ ﺑ ـﺪء اﻻﻧـﺪﻣﺎج اﻟﻨﻮوي . اﻟﻘﺮص اﻟﺬي ﻳﻈﻬﺮ ﰲ اﻟﺼﻮرة ﻋـﲆ ﺷﻜﻞ ﴍﻳﻂ ﻣﻈﻠﻢ أﻣﺎم ا ﺮﻛﺰ ا ﴩق ﻫـﻮ و ﺗﻘﺮﻳﺒﺎً ﻳﻤﺎﺛﻞ ﺣﺠﻢ ﻧﻈﺎﻣﻨﺎ اﻟﺸﻤﴘـ . ﻧﻈـﺮًا ﻟﻠﻜﺜﺎﻓﺔ ﻠﻴﻓ ﺲ ﻣﻦ اﻟﻐﺮﻳﺐ ﺗﺠﻤﻊ اﻟﻜﺜ ﻣﻦ ﻫـﺬه ا ـﻮاد ﻣـﻊ ﺑﻌﻀـﻬﺎ ﻟﺘﺸـﻜﻞ ﺑـﺪاﻳﺎت ﻟ ﻠﻜﻮاﻛﺐ اﻟﺠﺪﻳﺪة ﻮﻓﺮ ﺗ. L1527 ﻧﺎﻓـﺬة ﻋـﲆ ﻃﻔﻮﻟﺔ ﻣﺠﻤﻮﻋﺘﻨﺎ اﻟﺸﻤﺴﻴﺔ واﻟﺸﻤﺲ . ﻛﺸﻒ ﻳﻨﺎﻳﺮ ﻓ اﻳﺮ 2023