Free Astronomy Magazine January-February 2025 ARABIC VERSION

planet formation, migration, and sometimes destruction. Fully ma- tured stars like Vega have dusty disksenrichedbyongoing“bumper car” collisions among orbiting as- teroids and debris from evaporat- ing comets. These are primordial bodies that can survive up to the present 450-million-year age of Vega (our Sun is approximately ten times older than Vega). Dust within our solar system (seen astheZodiacallight)isalsoreplen- ishedbyminorbodiesejectingdust at a rate of about 10 tons per sec- ond. This dust is shoved around by planets. This provides a strategy for detecting planets around other starswithoutseeingthemdirectly– just by witnessing the effects they have on the dust. “Vega continues tobeunusual,” saidWolff. “Thear- chitecture of the Vega system is markedly different from our own solarsystemwheregiantplanets likeJupiterandSaturnarekeeping thedustfromspreadingthewayit does with Vega.” For comparison, there is a nearby star, Fomalhaut, which is about the same distance, age and tempera- ture as Vega. But Fomalhaut’s cir- cumstellar architecture is greatly different from Vega’s. Fomalhauthas three nested debris belts. Planetsaresuggestedasshepherd- ing bodies around Fomalhaut that gravitationallyconstrictthedust into rings, though no planets have been positively identified yet. “Giventhephysicalsimilaritybe- tweenthestarsofVegaandFoma- lhaut,whydoesFomalhautseemto havebeenabletoformplanetsand Vega didn’t?” said team member George Rieke of the University of Arizona, a member of the research team. “What’s the difference? Did the circumstellar environment, or thestaritself,createthatdiffer- ence? What’s puz- zling is that the same physics is at work in both,” added Wolff. Locatedinthesum- mer constellation Lyra,Vegaisoneof the brightest stars inthenorthernsky. Vega is legendary because it offered the first evidence for material orbit- ingastar–presum- ably the stuff for makingplanets–as potentialabodesof life. This was first hypothesized by Immanuel Kant in 1775. But it took over 200 years be- forethefirstobser- vational evidence was collected in 1984.Apuzzling excess of infrared light from warm dust was detected by NASA’s IRAS (Infrared Astronomy Satellite). Itwas interpreted as a shell or disk of dust extending twice the orbital ra- dius of Pluto from the star. In 2005 NASA’s infrared SpitzerSpace Telescope mapped out a ring of dust around Vega. This was fur- ther confirmed by observationsusing submillimeter telescopes in- cluding Caltech’s Submillimeter Ob- servatory on Mauna Kea, Hawaii,and also the Atacama Large Mil- limeter/submillimeter Array (ALMA) in Chile, and ESA’s (European Space Agency’s)HerschelSpaceTelescope, but none of these telescopes could see much detail. “The Hubble and Webb observa- tions together provide so much moredetailthattheyaretellingus something completely new about the Vega system that nobody knew before,” saidRieke.     JANUARY-FEBRUARY2025 22 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ ﻣﻨﻈﺮ ﺑﻮاﺳﻄﺔ ﺗﻠﺴ ﻮب و ﺐ اﻟﻔﻀﺎﺋﻲ ﻟﻘﺮصﻣﻦ اﻟﻐ ﺎرﻳ ﻠﻎ ﻋﺮﺿﮫ 100 ﻣﻠ ﺎرﻣﻴﻞ ﺣﻮل اﻟﻨ ﻢ اﻟﻨﺴﺮاﻟﻮاﻗﻊ . (ﻐﺎ ﻓ) اﻟﻘﺮص أﻣﻠﺲ ﺸ ﻞ ﻣﻠﺤﻮظوﻻ ﻈﻬﺮأيدﻟﻴﻞ ﻋﻠﻰ ﺗﺸ ﻞ اﻟ ﻮاﻛﺐ . ﻓ ﮫ [NASA,ESA,CSA,STScI,K.Su(Uni-versityofArizona),A.Gáspár(UniversityofArizona)] . ﺣﺪﻳﺜًﺎ ﻣـﻦ ا ﺤﺘﻤـ ﻞ أن ﺗﻜـﻮن اﻷﻗـﺮاص ﻣﻮاﻗﻊ ﻟﻠﻬﺠﺮة وأﺣﻴﺎﻧـ ﺎً اﻟﺘـﺪﻣ . اﻟﻨﺠـﻮم اﻟﻨﺎﺿﺠﺔ ﺗﻤﺎﻣﺎً ﻣﺜﻞ اﻟﻨﴪ اﻟﻮاﻗـﻊ (ﺎﻐـﻓﻴ) ﻟﻬﺎ أﻗﺮاص ﻏﺒﺎرﻳـﺔ ﻏﻨﻴـﺔ ﺑﺎﻻﺻـﻄﺪاﻣﺎت ا ﺴﺘﻤﺮة ﺑ اﻟﻜﻮﻳﻜﺒﺎت اﻟﺘﻲ ﺗﺪور ﺣﻮﻟﻬـﺎ واﻟﺤﻄﺎم اﻟﻨﺎﺗﺞ ﻋﻦ ا ﺬﻧﺒﺎت ا ﺘﺒﺨﺮة . إن ﻫﺬه ﻫﻲ اﻷﺟﺴﺎم اﻟﺒﺪاﺋﻴﺔ اﻟﺘﻲ ﻳﻤﻜﻦ أن ﺗﺒﻘﻰ ﻋﲆ ﻗﻴﺪ اﻟﺤﻴﺎة ﺣﺘﻰ ﻋﻤﺮ ﻓﻴﺠﺎ اﻟﺤﺎﱄ اﻟﺬي ﻳﺒﻠﻎ 450 ﻣﻠﻴﻮن ﺳﻨﺔ ) ﺷﻤﺴﻨﺎ أﻛـﱪ ﺳﻨﺎً ﻣـﻦ اﻟــﻨﴪ اﻟﻮاﻗـﻊ (ﺎﻐـﻓﻴ) ﺑﺤـﻮاﱄ ـﻋ (. ﴩة أﺿﻌﺎف إن اﻟﻐﺒﺎر داﺧﻞ ﻧﻈﺎﻣﻨﺎ اﻟﺸﻤﴘ ) اﻟﺬي ﻳُﺮى ﻋـﲆ أﻧ ـﻪ ﺿــﻮء اﻟــﱪوج ( ﻳﻤﺘﻠــﺊ أﻳﻀــﺎً ﺑﺎﻷﺟﺴـﺎم اﻟﺼـﻐ ة اﻟﺘـﻲ ﺗﻘـﺬف اﻟﻐﺒـﺎر ﺑﻤﻌﺪل ﺣﻮاﱄ 10 أﻃﻨﺎن ﰲ اﻟ ﺜﺎﻧﻴﺔ . إن ﻫﺬا اﻟﻐﺒﺎر ﺗﺪﻓﻌﻪ اﻟﻜﻮاﻛﺐ وﻫـﺬا ﻳـﻮﻓﺮ اﺳﱰاﺗﻴﺠﻴﺔ ﻟﻠﻜﺸﻒ ﻋـﻦ اﻟﻜﻮاﻛـﺐ ﺣـﻮل اﻟﻨﺠﻮ م ا ﻷﺧﺮى دون رؤﻳﺘﻬﺎ ﺑﺸﻜﻞ ﻣﺒـﺎﴍ واﻧﻤﺎ ﻣﻦ ﺧﻼل ﻣﺸـﺎﻫﺪة اﻟﺘـ ﺄﺛ ات اﻟﺘـﻲ ﺗﺨﻠﻔﻬﺎ ﻋﲆ اﻟﻐﺒﺎر . ﻳﻈـﻞ اﻟــﻨﴪ اﻟﻮاﻗـﻊ (ﺎﻐﻓﻴ) ﻏ ﻋﺎدي ﻛﻤﺎ ﻗﺎل ووﻟﻒ . إن ﺑﻨﻴـﺔ ﻧﻈﺎم ﻓﻴﺠﺎ ﻣﺨﺘﻠﻔﺔ ﺑﺸـﻜﻞ ﻣﻠﺤـﻮظ ﻋـﻦ ﻧﻈﺎﻣﻨـﺎ اﻟﺸﻤﴘـ ﺣﻴـﺚ ﺗﻌﻤـﻞ اﻟﻜﻮاﻛـﺐ ﻧﻈﺎم اﻟـﻨﴪ اﻟﻮاﻗﻊ (ﺎﻐﻓﻴ) ﻣﺨﺘﻠﻔﺔ ﺑﺸﻜﻞ ﻣﻠﺤﻮظ ﻋﻦ ﻧﻈﺎﻣﻨﺎ اﻟﺸﻤﴘﺣﻴـﺚ ﺗﻌﻤـﻞ اﻟﻜﻮاﻛﺐ اﻟﻌﻤﻼﻗﺔ ﻣﺜﻞ ا ﺸﱰي وزﺣﻞ ﻋﲆ ﻣﻨﻊ اﻟﻐﺒﺎر ﻣﻦ اﻻﻧﺘﺸـﺎر ﺑﺎﻟﻄﺮﻳﻘـﺔ اﻟﺘـﻲ ﻳﻔﻌﻠﻬﺎ اﻟﻨﴪ اﻟﻮاﻗﻊ ". (ﺎﻐﻓﻴ) ﻟﻠﻤﻘﺎرﻧﺔ ﻫﻨﺎك ﻧﺠﻢ ﻗﺮﻳـﺐ ) ﻓـﻢ اﻟﺤـﻮ (ت وﻫﻮ ﻋﲆ ﻧﻔـﺲ ا ﺴـﺎﻓﺔ واﻟﻌﻤـﺮ ودرﺟـﺔ اﻟﺤﺮارة ﺗﻘﺮﻳﺒ ﺎً ﻣﺜﻞ اﻟـﻨﴪ اﻟﻮاﻗﻊ (ﺎﻐـﻓﻴ) ﻟﻜﻦ اﻟﺒﻨﻴﺔ ا ﺤﻴﻄﺔ ﺑﻔ) ﻢ اﻟﺤﻮت ( ﻣﺨﺘﻠﻔـﺔ ﺗﻤﺎﻣًﺎ ﻋﻦ اﻟـﻨﴪ اﻟﻮاﻗﻊ . (ﺎﻐﻓﻴ) ﻳﺤﺘﻮي ) ﻓﻢ اﻟﺤـﻮت ( ﻋـﲆ ﺛﻼﺛـﺔ أﺣﺰﻣـﺔ ﺣﻄـﺎم ﻣﺘﺪاﺧﻠـﺔ . ﻳُﻘـﱰح وﺟـﻮد ﻛﻮاﻛـﺐ ﻛﺄﺟﺴﺎم ﺗﺎﺑﻌﺔ ) ﺣﻮل ﻓـﻢ اﻟﺤـﻮت ( ﺗﻌﻤـﻞ ﻋﲆ ﺗﻀ ﻴﻴﻖ اﻟﻐﺒﺎر ﺟﺎذﺑﻴﺎً ﰲ ﺷﻜﻞ ﺣﻠﻘـﺎت ﻋﲆ اﻟﺮﻏﻢ ﻣﻦ ﻋﺪم ﺗﺤﺪﻳﺪ أي ﻛﻮاﻛﺐ ﺑﺸﻜﻞ إﻳﺠﺎﺑﻲ ﺣﺘﻰ اﻵن . ﻗﺎل ﺟﻮرج رﻳﻜﻲ ﻋﻀﻮ اﻟﻔﺮﻳﻖ اﻟﺒﺤﺜﻲ ﻣﻦ ﺟﺎﻣﻌﺔ أرﻳﺰوﻧﺎ " : ﻧﻈﺮًا ﻟﻠﺘﺸﺎﺑﻪ اﻟﻔﻴﺰﻳـﺎﺋﻲ ﺑ ﻧﺠﻤﻲ اﻟــﻨﴪ اﻟﻮاﻗـﻊ ﻓـﻢ )و (ﺎﻐـﻓﻴ) اﻟﺤﻮت ( ﺎذا ﻳﺒـﺪو أن ) ﻓـﻢ اﻟﺤـﻮت ( ﻛـﺎن ﻗﺎدرًا ﻋﲆ ﺗﻜﻮﻳﻦ اﻟﻜﻮاﻛﺐ ﺑﻴﻨ ﻤﺎ ﻟﻢ ﻳـﺘﻤﻜﻦ ﻓﻴﺠﺎ ﻣﻦ ذﻟـﻚ؟ " ." ﻣـﺎ ﻫـﻮ اﻟﻔـﺮق؟ ﻫـﻞ ﺧﻠﻘﺖ اﻟﺒﻴﺌﺔ ا ﺤﻴﻄـﺔ ﺑـﺎﻟﻨﺠﻢ، أو اﻟـﻨﺠﻢ اﻟـﻨﴪ اﻟﻮاﻗﻊ (ﺎﻐﻓﻴ) ﻣﻦ ". ذﻟﻚ؟ أﺿﺎف ووﻟﻒ ﻣﺎ :" ﻫﻮ اﻟﻔﺮق؟ ﻫـﻞ ﺧﻠﻘـﺖ اﻟﺒﻴﺌ ﺔ ا ﺤﻴﻄﺔ ﺑﺎﻟﻨﺠﻢ أو اﻟﻨﺠﻢ ﻧﻔﺴﻪ ﻫﺬا اﻟﻔﺮق؟ اﻷﻣﺮ ا ﺤ ﻫﻮ أ ن ﻧﻔﺲ اﻟﻔﻴﺰﻳﺎء ﺗﻌﻤﻞ ﰲ ﻛﻠﻴﻬﻤﺎ . ﻳﻘــﻊ اﻟـــﻨﴪ اﻟﻮاﻗــﻊ (ﺎﻐﻓﻴ) ﰲ ﻛﻮﻛﺒﺔ اﻟﻘﻴ ﺜﺎرة اﻟﺼﻴﻔﻴﺔ وﻫﻮ أﺣـﺪ أ ـﻊ اﻟﻨﺠـــﻮم ﰲ اﻟﺴـــﻤﺎء اﻟﺸـــﻤﺎﻟﻴﺔ وﻳﺸـــﺘﻬﺮ اﻟــﻨﴪ اﻟﻮاﻗـﻊ (ﺎﻐـﻓﻴ) ﻷﻧﻪ ﻗﺪم أول دﻟﻴﻞ واﺿﺢ دوران ﻋـﲆ ا ـﺎدة ﺣـﻮل ﻧﺠﻢ وا ﻳ ﻟﺘﻲ ﻔﱰض أﻧﻬـ ﺎ ا ـﺎدة اﻟﻼزﻣـﺔ ﻟﺘﻜـﻮﻳﻦ اﻟﻜﻮاﻛﺐ ﻛﻤﻘﺮ ﻣﺤﺘﻤـﻞ ﻟﻠﺤﻴــﺎة وﻗــﺪ اﻓــﱰض إﻳﻤﺎﻧﻮﻳﻞ ﻛﺎﻧﻂ ﻫـﺬا ﻷول ﻣﺮة ﰲ ﻋﺎم 1775 وﻟﻜـﻦ اﻷﻣﺮ اﺳﺘﻐﺮق أﻛﺜـﺮ ﻣـﻦ ﺳـﺘﻐﺮق أﻛﺜـﺮ ﻣـﻦ ٢٠٠ ﻋﺎم ﻗﺒﻞ ﺟﻤﻊ أول دﻟﻴـﻞ 200 ﻋﺎم ﻗﺒﻞ ﺟﻤﻊ أول دﻟﻴﻞ ﰲ ﻋـﺎم 1984 وﻗﺪ اﻛﺘﺸﻒ ﻗﻤﺮ ﻧﺎﺳﺎ ا ﻟﺼﻨﺎﻋﻲ ﺑﺎﻷﺷـﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء ﻓﺎﺋﻀـ ﺎً اً ﻣﺤـ ﻣـﻦ اﻟ ﻀـﻮء ﺗﺤﺖ اﻷﺣﻤﺮ ﻣﻦ اﻟﻐﺒﺎر اﻟﺪاﻓﺊ و ﺗﻢ ﺗﻔﺴ ه ﻋﲆ أﻧﻪ ﻏﻼف أو ﻗﺮص ﻣﻦ اﻟﻐﺒﺎر ﻳﻤﺘـﺪ إﱃ ﺿﻌﻒ ﻧﺼﻒ ﻗﻄﺮ ﻣﺪار ﺑﻠﻮﺗﻮ ﻣﻦ اﻟﻨﺠﻢ . ﰲ ﻋ ـﺎم 2005 رﺳ ـﻢ ﺗﻠﺴ ـﻜﻮب ﺳــﺒﻴﺘﺰر اﻟﻔﻀﺎﺋﻲ ﺑﺎﻷﺷﻌﺔ ﺗﺤـﺖ اﻟﺤﻤـﺮاء اﻟﺘـﺎﺑﻊ ﻟﻮﻛﺎﻟﺔ ﻧﺎﺳﺎ ﺧﺮﻳﻄﺔ ﻟﺤﻠﻘﺔ ﻣﻦ اﻟﻐﺒﺎر ﺣﻮل اﻟﻨﴪ اﻟﻮاﻗﻊ (ﺎﻐﻓﻴ) وﺗﻢ ﺗﺎﻛﻴـﺪ ذﻟـﻚ ﻣـﻦ ﺧﻼل اﻷرﺻﺎد ﺑﺎﺳﺘﺨﺪام ﺗﻠﺴﻜﻮﺑﺎت ﺷﻤﻠﺖ ﻣﺮﺻﺪ دون ا ﻠﻴﻤﱰ اﻟﺘﺎﺑﻊ ﻌﻬﺪ ﻛﺎﻟﻴﻔﻮرﻧﻴﺎ ﻟﻠﺘﻜ ﻨﻮﻟ ﻮﺟﻴﺎ ﰲ ﻣﺎوﻧﺎ ﻛﻴﺎ ﰲ ﻫﺎواي وﻣﺮﺻﺪ أ ﺎ) ( ﰲ ﺗﺸﻴﲇ وﻣﺮﺻﺪ ﻫ ﺷـﻞ اﻟﻔﻀـﺎﺋﻲ اﻟﺘﺎﺑﻊ ﻟﻮﻛﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑﻴﺔ وﻟﻜـﻦ ﻟـﻢ ﺗﺘﻤﻜﻦ ﻛﻞ ﻫـﺬه اﻟﺘﻠﺴـﻜﻮﺑﺎ ت ﻣـﻦ رؤﻳـﺔ اﻟﻜﺜ ﻣﻦ اﻟﺘﻔﺎﺻﻴﻞ . ﻗﺎل رﻳﻚ " : ﺗﻮﻓﺮ أرﺻﺎد ﻫﺎﺑﻞ و وﻳـﺐ ﻣﻌـ ﺎ اﻟﻜﺜ ﻣﻦ اﻟﺘﻔﺎ ﺻﻴﻞ اﻟﺘﻲ ﺗﺨﱪﻧـﺎ ﺑـ ﴚء ـ ﺎً ﺟﺪﻳﺪ ﺗﻤﺎﻣ ﻋﻦ ﻧﻈﺎم اﻟﻨﴪ اﻟﻮاﻗﻊ (ﺎﻐﻓﻴ) ﻟﻢ ﻳﻜﻦ أﺣﺪ ﻳﻌﺮﻓﻪ ﻣﻦ ﻗﺒﻞ ." - ﻳﻨﺎﻳﺮ ﻓﺒﺮﺍﻳﺮ 2 0 2 5