Free Astronomy Magazine January-February 2025 ARABIC VERSION

F 30 ESO captures a “dark wolf” in the sky byESO BárbaraFerreira ound in the constellation Scor- pius,nearthecentreofthe MilkyWayonthesky,theDark WolfNebulaislocatedaround5300 light-years from Earth. This image takes up an area in the sky equiva- lenttofourfullMoons,butisactu- ally part of an even larger nebula called Gum 55. If you look closely, thewolfcouldevenbeawerewolf, itshandsreadytograbunsuspecting bystanders… If you thought that darkness equals emptiness, think again. Dark nebu- laearecoldcloudsofcosmicdust,so dense that they obscure the light of starsandotherobjectsbehindthem. As their name suggests, they do not emitvisiblelight,unlikeothernebu- lae. Dust grains within them absorb visible light and only let through ra- diation at longer wavelengths, like infrared light. Astronomers study these clouds of frozen dust because they often contain new stars in the making. Ofcourse,tracingthewolf’sghost- likepresenceintheskyisonlypossi- blebecauseitcontrastswithabright background. This image shows in spectaculardetailhowthedarkwolf standsoutagainsttheglowingstar- forming clouds behind it. The colourful clouds are built up mostlyofhydrogengasandglowin reddishtonesexcitedbytheintense UV radiation from the newborn starswithinthem.Somedarknebu- lae,liketheCoalsackNebula,canbe seenwiththenakedeye––andplay akeyroleinhowFirstNationsinter- pret the sky –– but not the Dark Wolf.Thisimagewascreatedusing datafromtheVLTSurveyTelescope, which is owned by the National In- stitute for Astrophysics in Italy (INAF)andishostedatESO’sParanal Observatory, in Chile’s Atacama Desert. The telescope is equipped withaspeciallydesignedcamerato mapthesouthernskyinvisiblelight. Thepicturewascompiledfromim- agestakenatdifferenttimes,each one with a filter letting in a differ- ent colour of light. They were all capturedduringtheVST Photomet- ricH α SurveyoftheSouthernGalac- ticPlaneandBulge(VPHAS+),which has studied some 500 million objects in our Milky Way. Surveys like this helpscientiststobetterunderstand the life cycle of stars within our homegalaxy,andtheobtaineddata aremadepubliclyavailablethrough theESOscienceportal.Explorethis treasuretroveofdatayourself:who knows what other eerie shapes you willuncoverinthedark?     ذﺋﺐ " ﺻﻮرة " داﻛﻦ ﻓﻲاﻟﺴﻤﺎء : ﻘﻠﻢ ﺎر ﺮا ﻓ ﺮا اﻟﻤﺮﺻﺪ اﻷوروﺑﻲ اﻟـﺠﻨﻮﺑﻲ ﺗــﻢ ﻄﻠــﻖ ــﺔ،اﻟ اﻟﺘﻘــﺎطﻫــﺬﻩ اﻟﺴــﺤﺎ ﺔ اﻟ ﻮﻧ ﻋﻠﻴﻬــــــﺎ اﺳــــــﻢ اﻟﺴــــــﺪ ﻢ ﻓــــــﻲﺻــــــﻮرة ﺪﻗــــــﺔ 283 ﻣﻠﻴـﻮن ﻜﺴــﻞ ﺑ ﻮاﺳــﻄﺔ ﺗﻠﺴـ ﻮب اﻟﻤﺴـﺢ اﻟﻜﺒــ ﺟـﺪاً ﻓـﻲﻣﺮﺻـﺪ ﺎراﻧـﺎل اﻟﺘـﺎﺑﻊ ﻟﻠﻤﺮﺻـﺪ اﻷوروﺑـﻲ ـاﻟ ﺠﻨﻮﺑﻲﻓﻲ ﺗﺸ ﻠﻲ ] . ESO/VPHAS [+ 30 ﻳﻮﺟــﺪ ﺳ ـﺪﻳﻢ اﻟ ـﺬﺋﺐ اﻟ ـﺪاﻛﻦ ﰲ ﻛﻮﻛﺒ ـﺔ اﻟﻌﻘﺮب ﺑﺎﻟﻘﺮ ب ﻣﻦ ﻣﺮﻛـﺰ درب اﻟﺘﺒﺎﻧـﺔ ﰲ اﻟﺴﻤﺎء و ﻳﺒﻌﺪ ﻣﺴـﺎﻓﺔ ﺣـﻮاﱄ 5300 ﺳـﻨﺔ ﺿﻮﺋﻴﺔ ﻣﻦ اﻷرض . ﺗﺸـﻐﻞ ﻫـﺬه اﻟﺼـﻮرة ﻣﺴـﺎﺣﺔ ﰲ اﻟﺴـﻤﺎء ﺗﻌـﺎدل أرﺑﻌـﺔ أﻗﻤـﺎر ﻛﺎﻣﻠﺔ، وﻟﻜﻨﻬﺎ ﰲ اﻟﻮاﻗﻊ ﺟـﺰء ﻣـﻦ ﺳـﺪﻳﻢ أﻛﱪ ﻳﺴﻤﻰ Gum 55 . إذا ﻧﻈﺮت ﻋﻦ ﻗـﺮب أن ﺗﺮى ﻓﻘﺪ اﻟـﺬﺋﺐ ﻣﺴـﺤﻔﺰاً ﺗﺒـﺪو ﻳـﺪاه ﺗﺎن ﻣﺴﺘﻌﺪ ﻻﺧﺘﻄﺎف ا ﺎرة اﻟﻐﺎﻓﻠ . إذا ﻛ ﻨﺖ ﺗﻌﺘﻘﺪ أن اﻟﻈـﻼم ﻳﺴـﺎوي اﻟﻔـﺮاغ ﻓﻔﻜﺮ ﻣﺮة أﺧﺮى . اﻟﺴﺪ ﺔ م ا ﻈﻠﻤ ﻋﺒﺎر ة ﻋﻦ ﺳﺤﺐ ﺑﺎردة ﻣـﻦ اﻟﻐﺒﺎر اﻟﻜﻮﻧﻲ ﻛﺜﻴﻔﺔ ﻟﺪرﺟﺔ أﻧﻬـﺎ ﺗﺤﺠـﺐ ﺿﻮء اﻟﻨﺠﻮم واﻷﺟﺴـﺎ م اﻷﺧـﺮى ﺧﻠﻔﻬـﺎ . وﻛﻤﺎ ﻳﻮﺣﻲ اﺳﻤﻬﺎ ﻓﻬـﻲ ﻻ ﺗﺼـﺪر ﺿـﻮءًا ﻣﺮﺋﻴﺎً ﻋﲆ ﻋﻜﺲ اﻟﺴﺪم اﻷﺧﺮى . ﺗﻤﺘﺺ ﺣﺒﻴﺒﺎت اﻟﻐﺒـﺎر ا ﻮﺟـﻮدة داﺧﻠﻬـﺎ اﻟﻀﻮء ا ﺮﺋﻲ وﻻ ﺗﺴﻤﺢ ﺑﻤﺮور ا ﻹﺷﻌﺎع إﻻ ﻋﻨﺪ أﻃﻮال ﻣﻮﺟﻴ ﻪ أﻃﻮل ﻣﺜﻞ ﺿﻮء اﻷﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء . ﻳﺪرس ﻋﻠﻤﺎء اﻟﻔﻠﻚ ﻫﺬه اﻟﺴﺤﺐ ﻣﻦ اﻟﻐﺒﺎر ا ﺘﺠﻤﺪ ﻷﻧﻬﺎ ﻏﺎﻟﺒًﺎ ﻣﺎ ﺗﺤﺘـﻮي ﻋـﲆ ﻧﺠـﻮم ﺟﺪﻳﺪة ﰲ ﻃﻮر اﻟﺘﻜﻮﻳ . ﻦ ﺑﺎﻟﻄﺒﻊ ﻣﻦ ا ﻤﻜﻦ ﺗﺘﺒﻊ وﺟﻮد اﻟﺬﺋﺐ اﻟﺸﺒﺢ ﰲ اﻟﺴـﻤﺎء ﻓﻘـﻂ ﺒﺎﻳﻦ ﻷﻧﻪ ﻳﺘ ﻣﻊ اﻟﺨﻠﻔﻴﺔ اﻟﺴﺎﻃﻌﺔ . ﺗُﻈﻬﺮ ﻫﺬه اﻟﺼﻮرة ﺑﺘﻔﺎﺻﻴﻞ ﻣﺬﻫﻠﺔ ﻛﻴـﻒ ﻳﱪز اﻟﺬﺋﺐ اﻟﺪاﻛﻦ أﻣﺎم اﻟﺴﺤﺐ ا ﺘﻮﻫﺠـﺔ اﻟﺘﻲ ﺗﺸﻜﻞ اﻟﻨﺠﻮم ﺧﻠﻔﻪ . ﺗﺘﻜﻮن اﻟﺴﺤﺐ ا ﻠﻮﻧﺔ ﰲ اﻟﻐﺎﻟﺐ ﻣـﻦ ﻏـﺎز اﻟﻬﻴ ـﺪروﺟ وﺗﺘ ـﻮﻫﺞ ﺑ ـﺪرﺟﺎت ﺣﻤ ـﺮاء ﺑﺴﺒﺐ اﻷﺷﻌﺔ ﻓﻮق اﻟﺒﻨﻔﺴـﺠﻴﺔ اﻟﺸـﺪﻳﺪة ﻧﺎﺗﺠ ـﺔ ﻋ ـﻦ اﻷﺷ ـﻌﺔ ﻓ ـﻮق اﻟﺒﻨﻔﺴ ـﺠﻴﺔ اﻟﺸـﺪﻳﺪة اﻟﺼـﺎدرة ﻋـﻦ اﻟﻨﺠـﻮم اﻟﻮﻟﻴــﺪة . داﺧﻠﻬﺎ ﻳﻤﻜﻦ رؤﻳﺔ ﺑﻌﺾ اﻟﺴﺪم ا ﻈﻠﻤـﺔ ﻣﺜﻞ ﺳﺪﻳﻢ ﻛـﻴﺲ اﻟﻔﺤـﻢ ﺑـﺎﻟﻌ ا ﺠـﺮدة وﺗﻠﻌﺐ دور اً ﺎً رﺋﻴﺴﻴ ﺗﻔ ﰲ ﻛﻴﻔﻴﺔ ﺴ اﻷﻣـﻢ اﻷوﱃ ﻟﻠﺴﻤﺎء وﻟﻜﻦ ﻟﻴﺲ اﻟﺬﺋﺐ اﻟﺪاﻛﻦ . ﺗﻢ إﻧﺸﺎء ﻫﺬه اﻟﺼﻮرة ﺑﺎﺳﺘﺨﺪام ﺑﻴﺎﻧـﺎت ﻣﻦ ﺗﻠﺴﻜﻮب ا ﺴﺢ اﻟﻜﺒـ ﺟـﺪاً ا ﻤﻠـﻮك ﻟﻠﻤﻌﻬﺪ اﻟﻮﻃ ﻨﻲ ﻟﻠﻔﻴﺰﻳﺎء اﻟﻔﻠﻜﻴﺔ ﰲ إﻳﻄﺎﻟﻴﺎ وا ﻮﺟﻮد ﰲ ﻣﺮﺻﺪ ﺑﺎراﻧﺎل اﻟﺘﺎﺑﻊ ﻟﻠﻤﺮﺻـﺪ اﻷوروﺑـﻲ اﻟﺠﻨـﻮﺑﻲ ﰲ ﺻـﺤﺮاء أﺗﺎﻛﺎﻣـﺎ ﰲ ﺗﺸـﻴﲇ . ﺗـﻢ ﺗﺠﻬﻴـ ﺰ اﻟﺘﻠﺴـﻜﻮب ﺑﻜـﺎﻣ ا ﻣﺼﻤﻤﺔ ﺧﺼﻴﺼ ﺎً ﻟﺮﺳﻢ ﺧﺮﻳﻄـﺔ ﻟﻠﻀـﻮء ﻏ ا ﺮﺋﻲ ﰲ اﻟﺴﻤﺎء اﻟﺠﻨﻮﺑﻴﺔ . ﺗﻢ ﺗﺠﻤﻴﻊ اﻟﺼﻮرة ﻣﻦ ﰲ ﻄـﺖ ﺻـﻮر اﻟﺘﻘ أوﻗﺎت ﻣﺨﺘﻠﻔﺔ ﻛﻞ ﻣﻨﻬﺎ ﻣﻦ ﺧﻼل ﺢ ﻣﺮﺷـ ﻳﺴﻤﺢ ﺑﺪﺧﻮل ﻟﻮن ﻣﺨﺘﻠﻒ ﻣﻦ اﻟﻀﻮء وﻗﺪ اﻟﺘﻘﻄﺖ ﻫـﺬه اﻟﺼـﻮر ﻣـﻦ ا ﺧـﻼل ﺴـﺢ اﻟ ﻔﻮﺗﻮﻣﱰي ﻟﺨﻂ ﻫﻴﺪروﺟ أﻟﻔﺎ ﺑﻮاﺳﻄﺔ ﺗﻠﺴﻜﻮب ا ﺴﺢ ﻟﻠﻤﺴﺘﻮى واﻻﻧﺘﻔﺎخ ا ﺠﺮي اﻟﺠﻨﻮﺑﻲ ) VPHAS (+ واﻟـﺬي درس ﺣـﻮاﱄ 500 ﻣﻠﻴﻮن ﺟﺮم .ﺗﻨﺎ ﰲ ﻣﺠﺮ ﻳ ﺴﺎﻋﺪ ﻣﺜﻞ ﻫﺬه ا ﺴﻮﺣﺎت ﻋﲆ ﻓﻬﻢ أﻓﻀﻞ ﻟـﺪو رة ﺣﻴـﺎة اﻟﻨﺠـﻮم ﰲ ﻣﺠﺮﺗﻨـﺎ ﺗـﻮﻓ و اﻟﺒﻴﺎﻧﺎت اﻟﺘﻲ ﻳ ﺘﻢ اﻟﺤﺼﻮل ﻋﻠﻴﻬﺎ ﻣﻦ ﺧﻼل ﺑﻮاﺑـﺔ ﻋﻠــﻮم ا ﺮﺻـﺪ اﻻروﺑـﻲ اﻟﺠﻨـﻮﺑﻲ . اﺳﺘﻜﺸﻒ ﺑﻨﻔﺴﻚ ﻫﺬا اﻟ ﻜﻨﺰ ﻣﻦ ا ﻌﻠﻮﻣﺎت ﻓﻘﺪ ﺗﺠﺪ أﺷﻜﺎ ﻻً أﺧﺮى ﰲ اﻟﻈﻼم .