{"id":10701,"date":"2023-12-17T15:54:57","date_gmt":"2023-12-17T15:54:57","guid":{"rendered":"https:\/\/www.africa-press.net\/sao-tome-e-principe\/politique\/le-double-visage-de-la-naine-blanche-janus"},"modified":"2023-12-17T17:20:58","modified_gmt":"2023-12-17T17:20:58","slug":"le-double-visage-de-la-naine-blanche-janus","status":"publish","type":"post","link":"https:\/\/www.africa-press.net\/sao-tome-e-principe\/toutes-les-actualites\/le-double-visage-de-la-naine-blanche-janus","title":{"rendered":"Le double visage de la naine blanche Janus"},"content":{"rendered":"

Africa-Press – S\u00e3o Tom\u00e9 e Pr\u00edncipe. <\/strong><\/span>Surprise en flagrant de\u0301lit de transition ! L\u2019e\u0301toile Janus, a\u0300 1300 anne\u0301es-lumie\u0300re, tourne sur elle-me\u0302me toutes les quinze minutes et sa luminosite\u0301 varie d\u2019un maximum lorsque sa face recouverte d\u2019hydroge\u0300ne est pointe\u0301e vers la Terre, a\u0300 un minimum lorsqu\u2019elle pre\u0301sente l\u2019he\u0301misphe\u0300re oppose\u0301, recouvert d\u2019he\u0301lium. Du jamais-vu pour une naine blanche.<\/p>\n

Une conversion en quelques secondes<\/b><\/p>\n

Certaines sont cependant connues pour, en se refroidissant, passer d\u2019une phase hydroge\u0300ne a\u0300 une phase he\u0301lium quand ce gaz remonte en surface a\u0300 cause de phe\u0301nome\u0300nes de convection au centre de l\u2019e\u0301toile. Mais cette conversion se fait normalement en quelques secondes et cette dichotomie est ine\u0301dite.<\/p>\n

Des champs magne\u0301tiques asyme\u0301triques ?<\/b><\/p>\n

Des champs magne\u0301tiques asyme\u0301triques pourraient jouer un ro\u0302le en empe\u0302chant l\u2019he\u0301lium de se me\u0301langer a\u0300 l\u2019hydroge\u0300ne du co\u0302te\u0301 de l\u2019he\u0301misphe\u0300re ou\u0300 ils sont les plus puissants, ou en influant sur la pression et la densite\u0301 de l\u2019atmosphe\u0300re, autorisant le maintien d\u2019un oce\u0301an d\u2019hydroge\u0300ne. D\u2019autres observations sont ne\u0301cessaires pour mieux comprendre cette e\u0301toile.<\/p>\n

Pour plus d’informations et d’analyses sur la S\u00e3o Tom\u00e9 e Pr\u00edncipe<\/a>, suivez Africa-Press<\/a><\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"

Africa-Press – S\u00e3o Tom\u00e9 e Pr\u00edncipe. Surprise en flagrant de\u0301lit de transition ! L\u2019e\u0301toile Janus, a\u0300 1300 anne\u0301es-lumie\u0300re, tourne sur elle-me\u0302me toutes les quinze minutes et sa luminosite\u0301 varie d\u2019un maximum lorsque sa face recouverte d\u2019hydroge\u0300ne est pointe\u0301e vers la Terre, a\u0300 un minimum lorsqu\u2019elle pre\u0301sente l\u2019he\u0301misphe\u0300re oppose\u0301, recouvert d\u2019he\u0301lium. Du jamais-vu pour une naine […]<\/p>\n","protected":false},"author":82,"featured_media":10700,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22,10],"tags":[36,55,56],"class_list":["post-10701","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-divers","category-toutes-les-actualites","tag-africa-press","tag-africa-press-sao-tome-e-principe","tag-sao-tome-e-principe"],"yoast_head":"\nLe double visage de la naine blanche Janus - S\u00e3o Tom\u00e9 e Pr\u00edncipe<\/title>\n<meta name=\"description\" content=\"Surprise en flagrant de\u0301lit de transition ! 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