Free Astronomy Magazine January-February 2026 ARABIC VERSION

A Aging white dwarf still consuming its planetary system byKeckObservatory Meagan O’Shea stronomers using data from theW.M.KeckObservatory onMaunakea,inHawai ‘ i, have identifiedarare,ancientplan- etarysystemstillbeingactivelycon- sumed by its central white dwarf star, LSPM J0207+3331. Located 145 light-years from Earth, this system hosts the oldest and most heavy metal-rich debris disk ever observed around ahydrogen-rich white dwarf, raising new questions about thelong- term stability of planetary sys- tems billions of years after stellar death when fusion has ended in the star.Thestudy,ledbyÉrikaLeBour- dais of the Trottier Institute for Re- search on Exoplanets at Universitéde Montréal, has been published in TheAstrophysicalJournal . “Thisdis- covery challenges our understand- ing of planetary system evolution,” said Le Bourdais. “Ongoing accre- tion at this stage suggests white dwarfs may also retain planetary remnantsstillundergoingdynami- cal changes.” Spectroscopic data obtained using the High-Resolution Echelle Spectrometer (HIRES) instru- ment on Keck I revealed the white dwarf’s atmosphere is polluted with 13 chemical elements, evidence of a rocky body at least 120 miles wide (200 kilometers) that was torn apart by the star’s gravity. “This is one of theveryfewtimeswecanseedirect evidence of planets being ripped apart and falling onto a dead star,” said Keck Observatory Chief Scien- tist John O’Meara. “We don’t have many of these systems where wesee polluted white dwarfs. This par- ticular system has the largest amount of heavy elements seen to date which proves it was an old, rocky planet.” Hydrogen-rich at- mospheres around white dwarfs typically mask such elemental signa- tures, making this detection espe- ciallysignificant. “Somethingclearly disturbed this system long after the star’sdeath,” saidco-investigator John Debes of the Space Telescope Science Institute in Baltimore, Mary- land. “There’sstillareservoirofma- terialcapableofpollutingthewhite dwarf, even after billions of years.” Nearly half of all polluted white dwarfs show signs of accretingheavy elements, indicating their planetary systems have been dy- namically disturbed. In the case of LSPM J0207+3331, a recent pertur- bation— within the last few million years—probablysentarockyplanet JANUARY-FEBRUARY2026 38 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ ﻗﺰم أﺑ ﺾﻋﺠﻮز ﻳ ﺘﻠﻊ ﻧﻈﺎﻣﮫ اﻟ ﻮﻛ : ﻘﻠﻢ ﻣ ﻐﺎن أوﺷ ﺎ ﻣﺮﺻﺪ ﻛ ﻚ ﺎﺳـﺘﺨﺪام ﺑﻴﺎﻧﺎت ﻣﻦ ﻣﺮﺻﺪ دﺑ ﻠﻴـﻮ . إم. ﻛﻴﻚ ﰲ ﻣﺎوﻧﺎك ﰲ ﻫﺎواي ﺗﻤﻜﻦ ﻋﻠﻤﺎء اﻟﻔﻠﻚ ﻣﻦ ﺗﺤﺪﻳﺪ ﻧﻈﺎم ﻛﻮﻛﺒﻲ ﻧﺎدر وﻗﺪﻳﻢ ﻻ ﻳﺰ ال ﻳﺘﻢ اﻣﺘﺼـﺎص ﺎدﺗـﻪ ﻣ ﺑﻨﺸـﺎط ﺑ ﻮاﺳـﻄﺔ ﻧﺠﻤـﻪ اﻟﻘـﺰم اﻷﺑـﻴﺾ ا ﺮﻛـﺰي ا ﺴـﻤﻰ LSPM J0207+3331 . ﻳﻘـﻊ ﻫـﺬا اﻟﻨﻈـﺎم ﻋـﲆ ﺑﻌـﺪ 145 ﺳـﻨﺔ ﺿـﻮﺋﻴﺔ ﻣـﻦ اﻷرض وﻳﻀﻢ أﻗﺪم ﻗﺮص ﺣﻄـﺎم ﻏﻨـﻲ ﺑﺎ ﻌـﺎدن اﻟﺜﻘﻴﻠﺔ ﺗﻢ رﺻ ﺪه ﺣـﻮل ﻗـﺰم أﺑـﻴﺾﻏﻨـﻲ ﺑﺎﻟﻬﻴﺪروﺟ ﻣﻤﺎ ﻳﺜ أﺳﺌﻠﺔ ﺟﺪﻳﺪة ﺣـﻮل اﻻﺳﺘﻘﺮار ﻃﻮﻳﻞ اﻷﻣﺪ ﻟﻸﻧﻈﻤـﺔ اﻟﻜﻮﻛﺒﻴـﺔ ﺑﻌ ﺪ ﻣﻠﻴﺎرات اﻟﺴﻨ ﻣﻦ وﻓﺎة اﻟﻨﺠﻢ واﻧﺘﻬﺎء اﻻﻧﺪﻣﺎج اﻟﻨﻮوي ﻓﻴﻪ . أﺟﺮت ﻫﺬه اﻟﺪراﺳـﺔ إرﻳﻜﺎ ﻟـﻮ ﺑـﻮردﻳﺲ ﻣـﻦ ﻣﻌﻬـﺪ ﺗﺮواﻳﺘﻴـﻪ ﻷﺑﺤــﺎث اﻟﻜ ﻮاﻛ ـﺐ اﻟﺨﺎرﺟﻴ ـﺔ ﰲ ﺟﺎﻣﻌ ـﺔ ﻣﻮﻧﱰﻳﺎل وﻗﺪ ﻧ ﴩت ﰲ ﻣﺠﻠﺔ ﻋﻠـﻢ اﻟﻔﻠـﻚ اﻟﻔﻴﺰﻳ ـﺎﺋﻲ وﻗﺎﻟــﺖ ﻟ ـﻮ ﺑ ـﻮردﻳﺲ ﻫ ـﺬا ": اﻻﻛﺘﺸﺎف ﻳﺘﺤﺪى ﻓﻬﻤﻨﺎ ﻟﺘﻄـﻮر اﻷﻧﻈﻤـﺔ اﻟﻜﻮﻛﺒﻴﺔ . اﻻﺳﺘﻤﺮار ﰲ اﻻﻣﺘﺼﺎص ﰲ ﻫـﺬه ا ﺮﺣﻠﺔ ﻳﺸـ إﱃ أن اﻷﻗـﺰام اﻟﺒﻴﻀـﺎء ﻗـﺪ ﺗﺤ ـﺘﻔﻆ أﻳﻀًـﺎ ﺑﺒﻘﺎﻳــﺎ ﻛﻮﻛﺒﻴ ـﺔ ﻻ ﺗــﺰال ﺧﺎﺿـﻌﺔ ﻟﺘﻐـ ات دﻳﻨﺎﻣﻴﻜﻴـﺔ ". أﻇﻬـﺮت ــــــــــــــــــــــــــــــــــــ ﻈﻬــــﺮ ﻫــــﺬا اﻟﺮﺳــــﻢ اﻟﺘﺨ ﻠــــﻲ ﻗﺰﻣــــﺎً أﺑــــ ﺾ ﻋﻤـــﺮﻩ ﺣـــﻮاﻟﻲ 3 ـــﺎراتﺳـــ ﻣﻠ ﻨﺔ وﻫـــﻮ ﻤـــﺘﺺ اﻟﻤــــﺎد اﻟﺴــــﺎﺑﻖ ــــﻮﻛ ــــﺎ ﻧﻈﺎﻣــــﮫ اﻟ ة ﻣــــﻦ ﻘﺎ ﺗﺴــــــﺒ ﺖ اﻻﺿــــــﻄﺮا ﺎت اﻟــــــ ـ ﺠ ﺬﺑ ﺔ ﻓــــــﻲ اﻧﺠــــــﺮاف ــﺎرﻧﺤــﻮ اﻟــﺪاﺧﻞ وﺗﻔ ﻜــﮫ ﻮﻛــﺐ ﻧﺠـﺎ ﻣــﻦ اﻻﻧﻬ ﺗﺤــﺖ ﻗــﻮى اﻟﻤـــﺪ واﻟــ ـ ﺠﺰر اﻟﺸــﺪ ﺪة ﻣﻤـــﺎ أد ــــﻮّن ﻗــــﺮصﻣــــﻦ اﻟــــ إﻟــــﻰ ﺗ ـ . ﺤﻄﺎم ﻟﻘــــﺪ أﻇﻬــــﺮ اﻟﺘﺤﻠﻴﻞ اﻟﻄ ﻔﻲ ﻟﻐﻼف اﻟﻘﺰم اﻷﺑ ﺾوﺟﻮد ـ ﻫﺬا اﻟ ﺤﻄﺎم اﻟ ﻮﻛ . [NASA/ESA/ Joseph Olmsted (STScI)] اﻟﺒﻴﺎﻧﺎت اﻟﻄﻴﻔﻴﺔ اﻟﺘﻲ ﺗﻢ اﻟﺤﺼـﻮل ﻋﻠﻴﻬـﺎ ﺑﺎﺳﺘﺨﺪام ﻣﻘﻴﺎس اﻟﻄﻴﻒ اﻹﺷﻌﺎﻋﻲ ﻋـﺎﱄ )ﺔ ﺪﻗاﻟ ( ﻫـﺎﻳﺮز ﻋـﲆ ﺗﻠﺴـﻜﻮب ﻛﻴـﻚ I أن ﻏﻼف اﻟﻘﺰم اﻷﺑﻴﺾ ﻣﻠﻮث ﺑـ 13 ﺮاً ـ ﻋﻨﺼـ ﻛﻴﻤﻴﺎﺋﻴﺎً وﻫﻮ دﻟﻴﻞ ﻋﲆ وﺟﻮد ﺟﺮم ﺻﺨﺮي ﺑﻌــﺮضﻻ ﻳﻘــﻞ ﻋــﻦ 120 ) ﻣــﻴﻼً 200 ( ﻛﻴﻠﻮﻣﱰ ﺗﻢ ﺗﻤﺰﻳﻘﻪ ﺑﻔﻌﻞ ﺟﺎذﺑﻴﺔ اﻟـﻨﺠﻢ . ﻗﺎل ﺟﻮن أو ﻣ ا ﻛﺒ ﻋﻠﻤﺎء ﻣﺮﺻـﺪ ﻛﻴـﻚ : " ﻫﺬه إﺣﺪى اﻟﺤﺎﻻت اﻟﻨﺎدرة اﻟﺘـﻲ ﻳﻤﻜﻨﻨـﺎ ﻓﻴﻬﺎ رؤﻳ ﺔ دﻟﻴﻞ ﻣﺒﺎﴍ ﻋﲆ ﺗﻤﺰﻳﻖ ﻛﻮاﻛـﺐ وﺳﻘﻮﻃﻬﺎ ﻋﲆ ﻧﺠﻢ ﻣﻴﺖ . ﻟﻴﺲ ﻟﺪﻳﻨﺎ اﻟﻌﺪ ﻳﺪ ﻣﻦ ﻫﺬه اﻷﻧﻈﻤﺔ ﺣﻴﺚ ﻧﺮى أﻗﺰاﻣ ﺎً ﺑﻴﻀـﺎء . ﻣﻠﻮﺛﺔ ﻫﺬا اﻟﻨﻈﺎم ﺑﺎﻟﺬات ﻳﺤﺘﻮي ﻋﲆ أﻛﱪ ﻛﻤﻴﺔ ﻣﻦ اﻟﻌﻨﺎﴏ اﻟﺜﻘﻴﻠﺔ اﻟﺘﻲ ﺗﻢ رﺻﺪﻫﺎ ﺣ ﺘﻰ اﻵن ﻣﻤﺎ ﻳﺜﺒﺖ أﻧﻪ ﻛﺎن ﻛﻮﻛﺒ ﺎً ﺎً ﺻﺨﺮﻳ ".ﺎً ﻗﺪﻳﻤ ﻋﺎدةً ﻣـﺎ ﺗﺨﻔـﻲ اﻷ ﻏﻠﻔـﺔ اﻟﻐ ﻨﻴـﺔ ﺑﺎﻟﻬﻴﺪروﺟ ﺣﻮل اﻷﻗـﺰام ا ﻟﺒﻴﻀـﺎء ﻣﺜـﻞ ﻫﺬه اﻟﺒﺼﻤﺎت ﻟﻠﻌﻨﺎﴏ ﻣﻤـﺎ ﻳﺠﻌـﻞ ﻫـﺬا اﻻﻛﺘﺸ ﺎف ذو أﻫﻤﻴـﺔ ﺧﺎﺻـﺔ . ﻗـﺎل ﺟـﻮن دﻳﺒﺲ اﻟﺒﺎﺣﺚ ا ﺸـﺎرك ﻣـﻦ ﻣﻌﻬـﺪ ﻋﻠـﻮم ﺗﻠﺴﻜﻮب اﻟﻔﻀﺎء ﰲ ﻣﺪﻳﻨﺔ ﺑﺎﻟﺘﻴﻤﻮر ﺑﻮﻻﻳـﺔ ”: ﻣ ﻳﻼﻧﺪ ﻫﻨﺎك ﳾء أزﻋـﺞ ﻫـﺬا اﻟﻨﻈـﺎم ـــــــــــــــــــــــــــــــــــ ﺑﻮﺿﻮح ﺑﻌﺪ وﻓﺎة اﻟﻨﺠﻢ ﺑﻔﱰة ﻃﻮﻳﻠﺔ . ﻻ ﻳﺰال ﻫﻨﺎك ﻣﺨﺰون ﻣﻦ ا ﺎدة ﻗـﺎدر ﻋـﲆ ﺗﻠﻮﻳـﺚ اﻟﻘـﺰم اﻷﺑـﻴﺾﺣﺘـﻰ ﺑﻌـﺪ ﻣــﺮور ﻣﻠﻴـﺎرات اﻟﺴـﻨ ." ﻳﻈﻬـﺮ ﺣـﻮاﱄ ﻧﺼـﻒ اﻷﻗــﺰام اﻟﺒﻴﻀ ـﺎء ا ﻠﻮﺛ ـﺔ ﻋﻼ ﻣ ـﺎت ﻋــﲆ اﻣﺘﺼﺎص اﻟﻌﻨﺎﴏ اﻟﺜﻘﻴﻠﺔ ﻣﻤﺎ ﻳﺸ إﱃ أن أﻧﻈﻤﺘﻬﺎ اﻟﻜﻮﻛﺒﻴﺔ ﻗﺪ ﺗﻌﺮﺿﺖ ﻻﺿﻄﺮاﺑﺎت د ﻳﻨﺎﻣﻴﻜﻴـﺔ . ﻳﻌﺘﻘـﺪ اﻧـﻪ ﰲ ﺣﺎﻟـﺔ اﻟﻘــﺰم اﻷﺑﻴﺾ LSPM J0207+3331 أن اﺿﻄﺮاﺑ ﺎً ﺎً ﺣﺪﻳﺜ ﺧﻼل ﻣﻼﻳ اﻟﺴﻨ اﻷﺧـ ة أدى إﱃ اﻧﺠﺮاف ﻛﻮﻛﺐ ﺻﺨﺮي ﻧﺤﻮ اﻟﺪاﺧﻞ . - ﻳﻨﺎﻳﺮ ﻓﺒﺮﺍﻳﺮ 2 0 2 6