Free Astronomy Magazine March-April 2026 ARABIC VERSION

planets in that it orbits a very old (twice as old as the Sun), iron-poor star in a region of the Milky Way knownasthethickdisk.Itmusthave formed in a very different chemical environmentfromtheplanetsinour ownsolarsystem.” Theplanet’scom- position could be representative of planets that formed when the uni- verse was relatively young. But an exotic composition can’t explain everything. The team also suspected that TOI-561 b might be surrounded by a thick atmosphere that makes it look larger than it actually is. Although small planets that have spentbillionsofyearsbakinginblaz- ingstellarradiationarenotexpected to have atmospheres, some show signsthattheyarenotjustbarerock orlava.Totestthehypothesisthat TOI-561 b has an atmosphere, the teamusedWebb’sNIRSpec(Near-In- frared Spectrograph) to measure the planet’sdaysidetemperaturebased on its near-infrared brightness. Thetechnique,whichinvolvesmeas- uring the decrease in brightness of thestar-planetsystemastheplanet movesbehindthestar,issimilarto thatusedtosearchforatmospheres in the TRAPPIST-1 system and on otherrockyworlds.IfTOI-561bisa bare rock with no atmosphere to carryheataroundtothenightside, its dayside temperature should be approaching4,900degreesFahren- heit(2,700degreesCelsius).Butthe NIRSpecobservationsshowthatthe planet’sdaysideappearstobecloser to3,200degreesFahrenheit(1,800 degrees Celsius) — still extremely hot,butfarcoolerthanexpected.To explaintheresults,theteamconsid- ered a few different scenarios. MARCH-APRIL2026 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 37 ﺗﻤﺎﻣــ ﺎً ﻋــﻦ ﺑﻴﺌــﺔ اﻟﻜﻮاﻛــﺐ ﰲ ﻧﻈﺎﻣﻨــﺎ اﻟﺸﻤﴘ . ﻗﺪ ﻳﻜﻮن ﺗﺮﻛﻴﺐ اﻟﻜﻮﻛﺐ ﻣﻤﺎ ﻳﺪل ﻋﲆ ﻛﻮاﻛﺐ ﺗﺸﻜﻠﺖ ﻋﻨﺪﻣﺎ ﻛﺎن ﻋﻤﺮ اﻟﻜﻮن اً ﺻﻐ . ﺎً ﻧﺴﺒﻴ ﻟﻜﻦ ﺗﺮﻛﻴﺒ ﺎً ﺎً ﻏﺮﻳﺒ ﻻ ﻳﻤﻜﻨـﻪ ﺗﻔﺴ ﻛﻞ ﳾء . ﻛﻤﺎ اﺷـﺘﺒﻪ اﻟﻔﺮﻳـﻖ ﰲ أن TOI-561 b ﻗﺪ ﻳﻜﻮن ﻣﺤﺎﻃ ﺎً ﺑﻐﻼف ﺟﻮي ﻛﺜﻴ ـﻒ ﻳﺠﻌﻠ ـﻪ ﻳﺒ ـﺪو أﻛ ـﱪ ﻣ ـﻦ ﺣﺠﻤ ـﻪ اﻟﺤﻘﻴﻘﻲ . ﻋﲆ اﻟﺮﻏﻢ ﻣﻦ أﻧـﻪ ﻻ ﻳ ﺘﻮﻗـﻊ أن ﺗﻤﺘﻠـﻚ اﻟﻜﻮاﻛـﺐ اﻟﺼـﻐ ة اﻟﺘـﻲ أﻣﻀـﺖ ﻣ ﻠﻴﺎرات اﻟﺴﻨ ﺗﺤﺖ أﺷﻌﺔ ﻧﺠﻤﻴﻪ ﺷﺪﻳﺪة اﻟﺤﺮارة أﻏﻠﻔﺔ ﺟﻮﻳﺔ إﻻ أن ﺑﻌﻀـﻬﺎ ﻳ ﻈﻬـﺮ ﻋﻼﻣﺎت ﺗﺪل ﻋﲆ أﻧﻬﺎ ﻟﻴﺴﺖ ﻣﺠﺮد ﺻـﺨﻮر ﺟﺮداء أو ﺣﻤﻢ ﺑﺮﻛﺎﻧﻴﺔ . وﻻﺧﺘﺒـﺎر ﻓﺮﺿـﻴﺔ أن TOI-561 b ﻳﻤﺘﻠﻚ ﻏﻼﻓًﺎ ﺟﻮﻳﺎً اﺳﺘﺨﺪم اﻟﻔﺮﻳﻖ ﻣﻄﻴـﺎف اﻷﺷـﻌﺔ ﺗﺤـﺖ اﻟﺤﻤـﺮاء ــــــــــــــــــــــــــــــــــــ ﻈﻬـــﺮ ﻫـــﺬا اﻟﺮﺳــــﻢ اﻟﺘﺨ ﻠــــﻲ ــــﻒ ﻤﻜــــﻦ أن ﻛ ــﻒﻓـﻮق ﻣﺤــ ﻂﻫﺎﺋــﻞ ـﺪو ﻏــﻼفﺟــﻮيﻛﺜ ﻳ ﻣــﻦ اﻟﺼــﻬﺎرة ﻋﻠــﻰ اﻟ ﻮﻛــﺐ اﻟــ ـ ﺨﺎرﺟﻲ TOI-561 b . اﻟﺘﻘﻄﻬـﺎ ﺗﻠﺴـ ﻮبﺟـ ﻤﺲ ﺗﺸ اﻟﻘ ﺎﺳﺎت اﻟـ و ﺐ اﻟﻔﻀﺎﺋﻲ اﻟﺘﺎﺑﻊ ﻟﻨﺎﺳﺎ إﻟﻰ أﻧـﮫ ﻋﻠـﻰ اﻟـﺮﻏﻢ ﺘﻠﻘــــﺎﻩ ﻣـــﻦ ﻧ ﻤــــﮫ ﻣـــﻦ اﻹﺷـــﻌﺎع اﻟﻤﻜﺜــــﻒ اﻟـــﺬ ﻓﺈن اﻟ ﻮﻛﺐ ﻟ ﺲﻣﺠﺮد ﺻﺨﺮة . ﻗﺎﺣﻠﺔ NASA, ESA, CSA, Ralf Crawford (STScI)] اﻟﻘﺮﻳﺒﺔ ) ﻧ ﺑﺴﻚ ( اﻟﺘﺎﺑﻊ ﻟﺘﻠﺴﻜﻮب ﺟﻴﻤﺲ وﻳﺐ ﻟﻘﻴﺎس درﺟﺔ ﺣﺮارة اﻟﺠﺎﻧﺐ اﻟﻨﻬـﺎري ﻟﻠﻜﻮﻛﺐ ﺑﻨﺎءً ﻋﲆ ﺳﻄﻮﻋﻪ ﰲ ﻧﻄﺎق اﻷ ﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء اﻟﻘﺮﻳﺒﺔ و ﻫﺬه اﻟﺘﻘﻨﻴـﺔ اﻟﺘـﻲ ﺗﺘﻀﻤﻦ ﻗﻴـﺎس اﻧﺨﻔـﺎض ﺳـﻄﻮع ﻧﻈـﺎم اﻟﻨﺠﻢ ﻋﻨﺪﻣﺎ ﻳﺘﺤﺮك اﻟﻜﻮﻛﺐ ﺧﻠﻔـ ﻪ ﺗﺸـﺒﻪ ﺗﻠﻚ ا ﺴﺘﺨﺪﻣﺔ ﻟﻠﺒﺤﺚ ﻋﻦ أﻏﻠﻔ ﺔ ﺟﻮﻳـﺔ ﰲ ﻧﻈﺎم ﺗﺮاﺑﺴﺖ -1 ﻋـﲆ و ﻛﻮاﻛـﺐ ﺻـﺨﺮﻳﺔ أﺧﺮى . إذا ﻛﺎن TOI-561 b ﺻﺨﺮة ﺟـﺮداء ﺑﺪون ﻏﻼف ﺟﻮي ﻟﻨﻘﻞ اﻟﺤﺮارة إﱃ اﻟﺠﺎﻧـﺐ ا ﻈﻠﻢ، ﻓﺈن درﺟﺔ ﺣﺮارة ﺟﺎﻧﺒـﻪ ا ـ ﴤء ـ ﻳﺠﺐ أن ﺗﻘﱰب ﻣﻦ 4900 درﺟﺔ ﻓﻬﺮﻧﻬ ﺎﻳﺖ ) 2700 درﺟــﺔ ﻣﺌﻮﻳــﺔ .( ﻟﻜـــﻦ ﺗ ﻈﻬــﺮ ﻣﻼﺣﻈﺎت ﻣﻄﻴﺎف ﻧ ﺑﺴﻚ أن درﺟﺔ ﺣﺮارة اﻟﺠﺎﻧﺐ ـا ﴤء ﻟﻠﻜﻮﻛﺐ TOI-561 b ﺗﺒﺪو ــــــــــــــــــــــــــــــــــــ أﻗﺮب إﱃ 3200 درﺟـﺔ ﻓ ﻬﺮﻧﻬﺎﻳـﺖ ) 1800 درﺟـﺔ ( ﻣﺌﻮﻳـﺔ ﻻ ﺗـﺰال ﺷـﺪﻳﺪة اﻟﺤـﺮارة وﻟﻜﻨﻬﺎ أﺑﺮد ﺑﻜﺜ ﻣﻤﺎ ﻛﺎن ﻣﺘﻮﻗﻌ . ﺎً إن ﻫﺬا اﻟﺘﺒﺎﻳﻦ اﻟﺤﺮاري ﻏ ا ﺘﻮﻗﻊ ﻳﺜ ﺗﺴـﺎؤﻻ ت ﺟﻮﻫﺮﻳﺔ ﺣﻮل ﺗﻜﻮﻳﻦ اﻟﻐﻼف اﻟﺠـﻮي ﻣﻤـﺎ اﺳ ﺘﻮﺟﺐ إﺟﺮاء ﺗﺤﻠﻴﻼت ﻣﻌﻘـﺪة وﺷـﺎﻣﻠﺔ ﺣﻴﺚ ﺳﻌﻰ اﻟﺒﺎﺣﺜﻮن ﺟﺎﻫﺪﻳﻦ ﻟﻔﻚ ﺷﻔﺮا ت اﻟﺒﻴﺎﻧﺎت اﻟـﻮاردة ﺑﺪﻗـﺔ ﰲ ﻣﺤﺎوﻟـﺔ ﻟﻔﻬـﻢ اﻟﺨﺼﺎﺋﺺ اﻟﻔﻴﺰﻳﺎﺋﻴﺔ اﻟﻐﺎﻣﻀﺔ اﻟﺘﻲ ﺗﻤﻴـﺰ اﻟﻜﻮﻛﺐ ﻫﺬا اﻟﺒﻌﻴﺪ وﻗﺪ ﻓﺤﺺ اﻟﻔﺮﻳﻖ ﺗﺄﺛ اﻟﻐﻼف اﻟﺠـﻮي ا ﺤﺘﻤـﻞ ﻋـﲆ اﻟﺘﻔـﺎﻋﻼت ا ﻐﻨﺎﻃﻴﺴﻴﺔ واﻟﺘﻮزﻳﻊ اﻟﺤﺮاري ﺑﺎﻹﺿـﺎ ﻓﺔ إﱃ اﻧﻌﻜﺎﺳﺎت اﻟﻀﻮء ﻋﲆ اﻟﺴﻄﺢ واﻟﺮﻳـﺎح اﻟﻘﻮﻳـﺔ ﻟﺘﻔو ﺴـ ﻫـﺬه اﻟﻨﺘـﺎﺋﺞ اﻓــﱰض اﻟﻔﺮﻳﻖ ﻋﺪد اً ﻣﻦ اﻟﺴﻴﻨﺎر ﻳﻮﻫﺎت ا ﺨﺘﻠﻔﺔ . - ﻣﺎﺭﺱ ﺃﺑﺮﻳﻞ 2 0 2 6