Free Astronomy Magazine September-October 2022 ARABIC VERSION

uring its temperature from Earth is no easy task. “This type of study is only possible with sensitive infrared images from large tel- escopes like the VLT that can observe Nep- tune clearly, and these have only been avail- able for the past 20 years or so,” says co- author Leigh Fletcher, a professor at the Uni- versity of Leicester. Around one third of all the images taken came from the VLT Im- ager and Spectrome- ter for mid-InfraRed (VISIR) instrument on ESO’s VLT in Chile’s Atacama Desert. Be- cause of the tele- scope’s mirror size and altitude, it has a very high resolution and data quality, of- fering the clearest images of Nep- tune. The team also used data from NASA’s Spitzer Space Telescope and images taken with the Gemini South telescope in Chile, as well as with the Subaru Telescope, the Keck Telescope, and the Gemini North ations were so unexpected, the as- tronomers do not know yet what could have caused them. They could Roman. “This all points towards a more complicated picture of Nep- tune’s atmosphere and how it changes with time.”     T Field adaptive optics mode of the MUSE instrument on ESO’s Very Large Telescope. The image he image of the planet Neptune on the left was obtained during the testing of the Narrow- on the right is a comparable image from the NASA/ESA Hubble Space Telescope. Note that the two images were not taken at the same time so do not show identical surface [ESO/P. Weilbacher (AIP)/NASA, ESA, and M.H. Wong and J. Tollefson (UC Berkeley)] T instrument. The images, taken between 2006 and 2021, show Neptune grad- he evolution of thermal images taken from Neptune using the VLT’s VISIR ually cooling down, before a dramatic heati g of its south pole in the last fe years. [ESO/M. Roman] ﻣﺠﻠﺔ Astronomy ﺎﻟﻌﺮ ﺔ ٣٠ إن اﻟﻘﻴـﺎم ﺑﻬـﺬا اﻟﻨـﻮع ﻣـﻦ اﻟﺪراﺳﺎت ﻳﻤﻜﻦ إﺟﺮاؤه ﻓﻘﻂ ﻣﻦ ﺧﻼل ﺻﻮر اﻷﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء اﻟﺤﺴﺎﺳﺔ ﺑﻮاﺳـﻄﺔ اﻟﺘﻠﺴﻜﻮﺑﺎت اﻟﻜﺒـ ة ﻓﻘـﻂ ﻣﺜﻞ اﻟﺘﻠﻴﺴﻜﻮب اﻟﻜ ﺒـ ﺟـﺪاً اﻟﺘــﺎﺑﻊ ﻟﻠﻤﺮﺻــﺪ اﻷوروﺑــﻲ اﻟﺠﻨﻮﺑﻲ اﻟﺬي ﻳﻤﻜﻨﻪ ﻣﺮاﻗﺒـﺔ ﻛﻮﻛﺐ ﻧﺒﺘﻮن ﺑﻮﺿﻮح وﻫـﺬا اﻷﻣﺮ أﺻﺒﺢ ﻣﺘﺎﺣﺎ ﻓﻘﻂ ﻋـﲆ ﻣﺪار اﻟﻌﴩﻳﻦ ﻋﺎﻣًﺎ ا ﺎﺿـﻴﺔ أو ﻧﺤﻮ ذﻟﻚ ." ﻳﻘـﻮل ا ﺆﻟـﻒ ا ﺸﺎرك ﱄ ﻓﻠﻴﺘﴩ اﻷﺳـﺘﺎذ ﰲ ﺟﺎﻣﻌﺔ ﻟﻴﺴﱰ :" إن ﻣﺎ ﻳﻘﺮب ﻣــﻦ ﺛﻠــﺚ ﺟﻤﻴــﻊ اﻟﺼــﻮر ا ﻠﺘﻘﻄﺔ ﻣﺼﺪرﻫﺎ ﻫﻮ ﺟﻬـﺎز اﻟﺘﺼ ـﻮﻳﺮ وﺟﻬ ـﺎز ﻣﻄﻴ ـﺎف اﻷﺷــﻌﺔ ﺗﺤــﺖ اﻟﺤﻤ ــﺮاء ﺑ ﺎﻟﺘﻠﺴـﻜﻮب اﻟﻜﺒ ـ ﺟـﺪاً ﰲ ﺻ ـﺤﺮاء أﺗﺎﻛﺎﻣ ـﺎ ﰲ ﺗﺸ ـﻴﲇ وﻧﻈﺮًا ﻟﺤﺠﻢ ﻣﺮآة اﻟﺘﻠﺴﻜﻮب وارﺗﻔﺎﻋﻪ، ﻓﺈﻧﻪ ﻳﺘﻤﺘﻊ ﺑﺪﻗﺔ وﺟﻮدة ﺑﻴﺎﻧﺎت ﻋﺎﻟﻴﺔ ﺟﺪاً ﻣﺎ ﻳﻮﻓﺮ ﺻــﻮر ﻋﺎﻟﻴــﺔ اﻟﻮﺿــﻮح ﻟﻜﻮﻛــﺐ ﻧﺒﺘــﻮن . ﻟﻘــﺪ اﺳـﺘﺨﺪم اﻟﻔﺮﻳـﻖ أﻳﻀًـﺎ ﺑﻴﺎﻧــﺎت ﻣـﻦ ﺗﻠﺴﻜﻮب ﺳﺒﻴﺘﺰر اﻟﻔﻀـﺎﺋﻲ اﻟﺘـﺎﺑﻊ ﻟﻮﻛﺎﻟـﺔ ﻧﺎﺳﺎ واﻟﺼﻮر اﻟﺘﻲ ﺗﻢ اﻟﺘﻘﺎﻃﻬـﺎ ﺑﺎﺳـﺘﺨﺪام ـــــ ﺗﻠﺴﻜﻮب ﺟﻴﻤﻨﻲ ﺳـﺎوث ا ﻮﺟـﻮد ﰲ ﺗﺸـﻴﲇ ﺳﻮﺑﺎرو وﺗﻠﺴﻜﻮب ﻛﻴﻚ وﺗﻠﺴﻜﻮب ﺟﻴﻤﻴﻨـﻲ ﻧ ـﻮرث ، وﻛﻠﻬ ـﺎ ﻣﻮﺟ ـﻮدة ﰲ ﻫــﺎواي وﻷن ﺗﻐـ ات درﺟـﺔ ﺣـﺮارة ﻧﺒﺘـﻮن ﻛﺎﻧـﺖ ﻏـ ﻣﺘﻮﻗﻌﺔ ، ﻓﺈن ﻋﻠﻤﺎء اﻟ ﻔﻠﻚ ﻻ ﻳﻌﺮﻓﻮن ﺣﺘـﻰ اﻵن ﻣﺎ اﻟﺬي أن ﻳﻜﻮن ﺳﺒﺒًﺎ ﻟﻬﺎ، ﻓﻘﺪ ﺗﻜـﻮن ﺑﺴـــﺒﺐ اﻟﺘﻐـــ ات ﰲ ﻛﻴﻤﻴـــﺎء ﻃﺒﻘـــﺔ اﻟﺴﱰاﺗﻮﺳﻔ أو أﻧﻤﺎط اﻟﻄﻘﺲ اﻟﻌﺸـﻮاﺋﻴﺔ أو ﺣﺘﻰ ﻧﺸﺎط اﻟﺪورة اﻟﺸﻤﺴﻴﺔ، ﻟﺬﻟﻚ ﻫﻨـﺎك ﺣﺎﺟﺔ ﺰﻳـﺪ ﻣـﻦ اﻷرﺻـﺎد ﺧـﻼل اﻟﺴـﻨﻮات اﻟﻘﺎدﻣﺔ ﻻﺳﺘﻜﺸﺎف أﺳﺒﺎب ﻫـﺬه اﻟﺘﻘﻠﺒـﺎت . ﻳﻤﻜﻦ ﻟﻠﺘﻠﺴﻜﻮﺑﺎت اﻷ رﺿﻴﺔ ا ﺴﺘﻘﺒﻠﻴﺔ ﻣﺜـﻞ ﺗﻠﺴﻜﻮب اﻟﻔﻀﺎء اﻟﺨـﺎرﺟﻲ اﻟﻜﺒـ ﻟﻠﻐﺎﻳـﺔ ) LT أن ﻳﺮاﻗﺐ ﺗﻐ ات درﺟﺔ اﻟﺤﺮارة ﻋـﲆ ﻧﺒﺘ ـﻮن ﺑﻤﺰﻳ ـﺪ ﻣـﻦ اﻟﺘﻔﺼـﻴﻞ، ﰲ ﺣ ـ أن ﺗﻠﺴﻜﻮب ﺟﻴﻤﺲ وﻳﺐ ﺳﻴﻮﻓﺮ ﺧﺮاﺋﻂ ﺟﺪﻳﺪة ﻏ ﻣﺴﺒﻮﻗﺔ ﻟﻠﻜﻴﻤﻴـﺎء ودرﺟـﺔ اﻟﺤـﺮارة ﰲ اﻟﻐﻼف اﻟﺠﻮي ﻟﻨﺒﺘﻮن . ﻳﻘﻮل روﻣﺎن " : أﻋﺘﻘﺪ أن ﻧﺒﺘﻮن ﻣﺜ ﻟﻼ ﻫﺘﻤﺎم ﻟﻠﻜﺜ ﻳﻦ ﻷﻧﻨﺎ ﻣﺎ زﻟﻨﺎ ﻧﻌﺮف ﻻ إﻻ اﻟﻘﻠﻴﻞ ﻋﻨﻪ ." ﺗﻠﺴ ﻮبﻫﺎﺑﻞ اﻟﻔﻀ ﺎﺋﻲ اﻟﺘﻠﺴ ﻮب اﻟﻜﺒ ﺟﺪاً ) (VLT ﺗــﻢ اﻟـــ ـ ــﺔ ﻟﻠﻤﺠـــﺎل اﻟﻀـــﻴﻖ ــﺎروﺿـــﻊ اﻟ ﺼـــﺮ ﺎت اﻟﺘﻜ ﻔ ﺤﺼﻮل ﻋﻠـــﻰﺻــﻮرة ﻮﻛـــﺐ ﻧ ﺘـــﻮن ﻋﻠــﻰ اﻟ ﺴـــﺎر أﺛﻨـــﺎء اﺧﺘ ﻟـــﺠﻬﺎز (MUSE) ﻋﻠﻰ اﻟﺘﻠﺴ ﻮب اﻟ ﻜﺒ ﺟﺪًا (VLT) ﻫﻲﺻﻮرة ﻟﻠﻤﻘﺎرﺔ ﻣﻦ ﺗﻠﺴ ﻮب ﻫﺎﺑـﻞ اﻟﻔﻀـﺎﺋﻲ اﻟﺼﻮرة ﻋﻠﻰ اﻟ ﻤ ﻋ ﻓﻲ ﻧﻔﺲ اﻟﻮﻗﺖ ﻟﺬﻟﻚ ﻻ ﺗﻈﻬﺮﻧﻔﺲ اﻟﺴﻄﺢ ﻠﻤﺎ ﺄﻧﮫ ﻟﻢ ﺘﻢ اﻟﺘﻘﺎط اﻟﺼﻮر . ﺗﻄـﻮر اﻟﺼـﻮراﻟـ ـ ﺤﺮار ﺔ اﻟﻤـﺄﺧﻮذة ﻣـﻦ ﻧ ﺘـﻮن ﺎﺳـﺘﺨﺪام ﺟﻬـﺎز (VISIR) ﻣـﻊ اﻟﺘﻠﺴـ ﻮب اﻟﻜﺒـ ﺟـﺪاً ) (VLT ﻋــﺎﻣﻲ اﻟﺘﻘﻄــﺖ ﺑــ اﻟـ ٢٠٠٦ و ٢٠٢١ ، ﺗﻈﻬـﺮﻧ ﺘــﻮن ﻳــ د ﺗــﺪر ﺠ ًﺎ ﻗﺒـﻞ ﺗﺴــ دراﻣـﺎﺗ ﻜﻲ ﺨ ﻟﻘﻄ ﮫ ا ﻨﻮﺑﻲ ﻓﻲ اﻟﺴﻨﻮات اﻟﻘﻠ ﻠﺔ اﻟﻤﺎﺿ ﺔ . ﺳﺒﺘﻤ أﻛﺘﻮﺑﺮ 2022 [ESO/P. Weilbacher (AIP)/NASA, ESA, and M.H. Wong and J. Tollefson (UC Berkeley)] [ESO/M. Roman]