{"id":602,"date":"2022-04-08T19:28:21","date_gmt":"2022-04-08T17:28:21","guid":{"rendered":"http:\/\/www.cosmoespai.com\/cat\/?p=602"},"modified":"2022-04-08T19:28:21","modified_gmt":"2022-04-08T17:28:21","slug":"per-que-les-estrelles-no-tenen-totes-el-mateix-color","status":"publish","type":"post","link":"https:\/\/www.cosmoespai.com\/cat\/per-que-les-estrelles-no-tenen-totes-el-mateix-color\/","title":{"rendered":"Per qu\u00e8 les estrelles no tenen totes el mateix color?"},"content":{"rendered":"\n<p class=\"has-text-align-justify\">Al llarg del temps, la humanitat ha mirat les estrelles amb fascinaci\u00f3. A simple vista, la majoria d\u2019elles semblen ser blanques. Fins fa uns segles, la majoria dels cient\u00edfics creien que tots les estrelles eren blanques. No obstant, amb els aven\u00e7os en la tecnologia, i gr\u00e0cies a telescopis cada cop m\u00e9s potents, hem pogut apreciar que les estrelles brillen en una gran varietat de colors.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><em><u><strong>La temperatura de l\u2019estrella<\/strong><\/u><\/em><\/h4>\n\n\n\n<p class=\"has-text-align-justify\">El color d\u2019una estrella dep\u00e8n, majorit\u00e0riament, de la seva temperatura. Com m\u00e9s llum emet una estrella, m\u00e9s alta \u00e9s la seva temperatura. Per entendre com la llum que emet una estrella afecta el seu color, necessitem con\u00e8ixer, en primer lloc, les caracter\u00edstiques de la llum.<\/p>\n\n\n\n<p class=\"has-text-align-justify\">La llum viatja a trav\u00e9s l\u2019espai en forma d\u2019ones. Com tot tipus d\u2019ona, t\u00e9 pics, on l\u2019energia \u00e9s m\u00e0xima, i valls, on l\u2019energia \u00e9s m\u00ednima. La dist\u00e0ncia entre dos pics (o valls) consecutius \u00e9s el que s\u2019anomena longitud d\u2019ona. Com m\u00e9s llarga sigui la longitud d\u2019ona, menys energia tindr\u00e0 aquell tipus de llum en concret. En el cas de la llum visible, la llum menys energ\u00e8tica \u00e9s la de color vermell.<\/p>\n\n\n\n<p class=\"has-text-align-justify\">Per altra banda, la llum amb una longitud d\u2019ona menor, i per tant m\u00e9s energ\u00e8tica, correspon al color blau, tirant al lila, en l\u2019espectre de la llum visible.<\/p>\n\n\n\n<p class=\"has-text-align-justify\">Com \u00e9s natural, les estrelles m\u00e9s petites i, per tant les menys brillants de l\u2019univers, emeten llum de baixa energia. \u00c9s per aquest motiu que les nanes vermelles, que s\u00f3n les estrelles m\u00e9s petites de l\u2019univers, s\u00f3n vermelles (com el seu nom indica).<\/p>\n\n\n\n<p class=\"has-text-align-justify\">En canvi, les estrelles m\u00e9s grans i lluminoses emeten molta llum d\u2019alta energia. Aquest tipus de llum, associada amb el color blau, \u00e9s el que dona el caracter\u00edstic color blau a les estrelles m\u00e9s brillants i calentes.<\/p>\n\n\n\n<p class=\"has-text-align-justify\">\u00c9s important mencionar que les estrelles emeten llum de totes les longituds d\u2019ona. No obstant, cada estrella emet un tipus de llum majoritari, que \u00e9s el que dona el color a l\u2019estrella. Quan una estrella emet llum en moltes longituds d\u2019ona, en quantitats m\u00e9s o menys similars, la veiem de color blanc.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><em><u><strong>Composici\u00f3 estel\u00b7lar<\/strong><\/u><\/em><\/h4>\n\n\n\n<p class=\"has-text-align-justify\">La temperatura no \u00e9s l\u2019\u00fanic factor que determina el color d\u2019una estrella. Una estrella est\u00e0 composta d\u2019una gran varietat d\u2019elements, i aquests \u00faltims tamb\u00e9 dicten el color d\u2019un astre. Les estrelles estan formades majorit\u00e0riament per hidrogen i heli, i altres elements en petites quantitats.<\/p>\n\n\n\n<p class=\"has-text-align-justify\">El percentatge d\u2019aquests elements varia d\u2019estrella en estrella. Aquest canvi en la composici\u00f3 de les estrelles pot afectar la seva temperatura, i, per tant, el tipus de llum que emet.<\/p>\n\n\n\n<p class=\"has-text-align-justify\">Per tant el color d\u2019una estrella pot indicar als cient\u00edfics la seva temperatura aproximada, per\u00f2 tamb\u00e9 l\u2019abund\u00e0ncia de certs elements existents en la mateixa.<\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<p><strong>Entrades Similars:<\/strong><\/p>\n\n\n\n<p><a href=\"http:\/\/www.cosmoespai.com\/cat\/quins-tipus-destels-hi-ha\/\">Quins tipus d\u2019estels hi ha?<\/a><\/p>\n\n\n\n<p><a href=\"http:\/\/www.cosmoespai.com\/cat\/com-neixen-les-estrelles\/\">Com neixen les estrelles?<\/a><\/p>\n\n\n\n<p><a href=\"http:\/\/www.cosmoespai.com\/cat\/es-possible-la-vida-al-voltant-de-nanes-vermelles\/\">\u00c9s possible la vida al voltant de nanes vermelles?<\/a><\/p>\n\n\n\n<p><a href=\"http:\/\/www.cosmoespai.com\/cat\/459\/\">Qu\u00e8 s\u00f3n les estrelles de neutrons? Formaci\u00f3 i caracter\u00edstiques<\/a><\/p>\n\n\n\n<p><strong>Entrades Populars:<\/strong><\/p>\n\n\n\n<p><a href=\"http:\/\/www.cosmoespai.com\/cat\/perque-la-lluna-nomes-ens-ensenya-una-cara\/\">Perqu\u00e8 la Lluna nom\u00e9s ens ensenya una cara?<\/a><\/p>\n\n\n\n<p><a href=\"http:\/\/www.cosmoespai.com\/cat\/stephenson-2-18-lestrella-mes-gran-coneguda-a-lunivers\/\">Stephenson 2-18, l\u2019estrella m\u00e9s gran coneguda a l\u2019univers<\/a><\/p>\n\n\n\n<p><a href=\"http:\/\/www.cosmoespai.com\/cat\/lexplotacio-minera-al-cinturo-dasteroides-una-font-de-recursos\/\">L\u2019explotaci\u00f3 minera al cintur\u00f3 d\u2019asteroides, una font de recursos<\/a><\/p>\n\n\n\n<p><a href=\"http:\/\/www.cosmoespai.com\/cat\/la-brossa-espacial-un-gran-problema\/\">La brossa espacial, un gran problema<\/a><\/p>\n\n\n\n<p><a href=\"http:\/\/www.cosmoespai.com\/cat\/com-es-van-extingir-els-dinosaures\/\">Com es van extingir els dinosaures?<\/a><\/p>\n\n\n\n<p><a href=\"http:\/\/www.cosmoespai.com\/cat\/que-passaria-si-la-terra-deixes-de-rotar\/\">Qu\u00e8 passaria si la Terra deix\u00e9s de rotar?<\/a><\/p>\n\n\n\n<p><a href=\"http:\/\/www.cosmoespai.com\/cat\/la-missio-a-venus-de-la-sonda-venus-express-per-la-esa\/\">La missi\u00f3 a Venus de la sonda Venus Express per la ESA<\/a><\/p>\n\n\n\n<p><a href=\"http:\/\/www.cosmoespai.com\/cat\/quins-son-els-requisits-per-a-ser-un-planeta\/\">Quins s\u00f3n els requisits per a ser un planeta?<\/a><\/p>\n\n\n\n<p><a href=\"http:\/\/www.cosmoespai.com\/cat\/perque-no-es-poden-sentir-sons-a-lespai\/\">Perqu\u00e8 no es poden sentir sons a l\u2019espai?<\/a><\/p>\n\n\n\n<p><a href=\"http:\/\/www.cosmoespai.com\/cat\/quina-mida-i-forma-tindrien-els-extraterrestres\/\">Quina mida i forma tindrien els extraterrestres?<\/a><\/p>\n\n\n\n<p><a href=\"http:\/\/www.cosmoespai.com\/cat\/les-unitats-de-mesura-que-fem-servir-en-astronomia\/\">Les unitats de mesura que fem servir en astronomia<\/a><\/p>\n\n\n\n<p><strong>Entrades Recents:<\/strong><\/p>\n\n\n<ul class=\"wp-block-latest-posts__list is-grid columns-3 wp-block-latest-posts\"><li><a class=\"wp-block-latest-posts__post-title\" href=\"https:\/\/www.cosmoespai.com\/cat\/com-viatjar-al-futur-sense-violar-les-lleis-de-la-fisica\/\">Com Viatjar al Futur Sense Violar les Lleis de la F\u00edsica<\/a><\/li>\n<li><a class=\"wp-block-latest-posts__post-title\" href=\"https:\/\/www.cosmoespai.com\/cat\/que-es-la-gravetat\/\">Qu\u00e8 \u00e9s la gravetat?<\/a><\/li>\n<li><a class=\"wp-block-latest-posts__post-title\" href=\"https:\/\/www.cosmoespai.com\/cat\/per-que-hi-ha-mes-materia-que-antimateria-a-lunivers\/\">Per qu\u00e8 hi ha m\u00e9s mat\u00e8ria que antimat\u00e8ria a l\u2019univers?<\/a><\/li>\n<li><a class=\"wp-block-latest-posts__post-title\" href=\"https:\/\/www.cosmoespai.com\/cat\/que-es-lantimateria\/\">Qu\u00e8 \u00e9s l\u2019antimat\u00e8ria?<\/a><\/li>\n<li><a class=\"wp-block-latest-posts__post-title\" href=\"https:\/\/www.cosmoespai.com\/cat\/per-que-els-centres-de-les-galaxies-contenen-forats-negres\/\">Per qu\u00e8 els centres de les gal\u00e0xies contenen forats negres?<\/a><\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<p>Al llarg del temps, la humanitat ha mirat les estrelles amb fascinaci\u00f3. A simple vista, la majoria d\u2019elles semblen ser blanques. Fins fa uns segles,<span class=\"read-more-link\"><a class=\"read-more\" href=\"https:\/\/www.cosmoespai.com\/cat\/per-que-les-estrelles-no-tenen-totes-el-mateix-color\/\">Continuar llegint<\/a><\/span><\/p>\n","protected":false},"author":1,"featured_media":604,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_mi_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":""},"categories":[5,1],"tags":[364,396,186,344,31,63,256,55],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2022\/04\/Color_Estrelles.jpg?fit=720%2C405","jetpack_sharing_enabled":true,"jetpack_likes_enabled":true,"jetpack-related-posts":[{"id":435,"url":"https:\/\/www.cosmoespai.com\/cat\/per-que-el-mar-es-de-color-blau\/","url_meta":{"origin":602,"position":0},"title":"Per qu\u00e8 el mar \u00e9s de color blau?","author":"Ferran","date":"27 d'agost de 2021","format":false,"excerpt":"En general es creu que el mar t\u00e9 el seu caracter\u00edstic color blau ja que reflecteix el color del cel. Tot i que aquesta afirmaci\u00f3 \u00e9s en part certa, no \u00e9s l\u2019\u00fanica ni principal ra\u00f3. La resposta a aquesta pregunta es troba en la forma en que les mol\u00e8cules d\u2019aigua\u2026","rel":"","context":"A &quot;La Terra&quot;","block_context":{"text":"La Terra","link":"https:\/\/www.cosmoespai.com\/cat\/category\/sistema-solar\/la-terra\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2021\/08\/Mar_ColorBlau.jpg?fit=720%2C405&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2021\/08\/Mar_ColorBlau.jpg?fit=720%2C405&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2021\/08\/Mar_ColorBlau.jpg?fit=720%2C405&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2021\/08\/Mar_ColorBlau.jpg?fit=720%2C405&resize=700%2C400 2x"},"classes":[]},{"id":908,"url":"https:\/\/www.cosmoespai.com\/cat\/com-produeixen-energia-les-estrelles\/","url_meta":{"origin":602,"position":1},"title":"Com produeixen energia les estrelles?","author":"Ferran","date":"7 de maig de 2023","format":false,"excerpt":"El Sol, la nostra estrella m\u00e9s propera, \u00e9s essencial per la pres\u00e8ncia de vida a la Terra, gr\u00e0cies a la llum i calor que emet. L\u2019univers est\u00e0 poblat per bilions d\u2019estrelles, que il\u00b7luminen el nostre cel de nit, i amb les quals podem obtenir unes imatges impressionants del cosmos. Per\u00f2,\u2026","rel":"","context":"A &quot;Estrelles&quot;","block_context":{"text":"Estrelles","link":"https:\/\/www.cosmoespai.com\/cat\/category\/estrelles\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2023\/05\/Energia_Estrelles.jpg?fit=720%2C405&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2023\/05\/Energia_Estrelles.jpg?fit=720%2C405&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2023\/05\/Energia_Estrelles.jpg?fit=720%2C405&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2023\/05\/Energia_Estrelles.jpg?fit=720%2C405&resize=700%2C400 2x"},"classes":[]},{"id":535,"url":"https:\/\/www.cosmoespai.com\/cat\/per-que-el-cel-de-nit-es-fosc\/","url_meta":{"origin":602,"position":2},"title":"Per qu\u00e8 el cel de nit \u00e9s fosc?","author":"Ferran","date":"15 de gener de 2022","format":false,"excerpt":"Aquesta pregunta se l\u2019han plantejat els astr\u00f2noms des de fa m\u00e9s de 400 anys. Tot i aix\u00ed, la formulaci\u00f3 oficial d\u2019aquesta paradoxa la devem al metge alemany Heinrich Wilhelm Olbers. Des de llavors, es coneix com la paradoxa d\u2019Olbers. I si b\u00e9 \u00e9s una pregunta simple, la seva soluci\u00f3 va\u2026","rel":"","context":"A &quot;Univers&quot;","block_context":{"text":"Univers","link":"https:\/\/www.cosmoespai.com\/cat\/category\/univers\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2022\/01\/CelNit_Fosc.jpg?fit=720%2C405&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2022\/01\/CelNit_Fosc.jpg?fit=720%2C405&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2022\/01\/CelNit_Fosc.jpg?fit=720%2C405&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2022\/01\/CelNit_Fosc.jpg?fit=720%2C405&resize=700%2C400 2x"},"classes":[]},{"id":759,"url":"https:\/\/www.cosmoespai.com\/cat\/quina-es-lestrella-mes-propera-a-la-terra\/","url_meta":{"origin":602,"position":3},"title":"Quina \u00e9s l\u2019estrella m\u00e9s propera a la Terra?","author":"Ferran","date":"9 d'octubre de 2022","format":false,"excerpt":"\u00d2bviament, l\u2019estrella m\u00e9s propera a la Terra \u00e9s l\u2019estrella central del nostre sistema solar: el Sol. La nostra estrella pertany a la categoria de nana groga, i existeix des de fa 5.000 milions d\u2019anys. Sense el Sol no existiria vida a la Terra. L\u2019estrella es troba a 150 milions de\u2026","rel":"","context":"A &quot;Estrelles&quot;","block_context":{"text":"Estrelles","link":"https:\/\/www.cosmoespai.com\/cat\/category\/estrelles\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2022\/10\/Estrella_PropTerra.jpg?fit=720%2C405&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2022\/10\/Estrella_PropTerra.jpg?fit=720%2C405&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2022\/10\/Estrella_PropTerra.jpg?fit=720%2C405&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2022\/10\/Estrella_PropTerra.jpg?fit=720%2C405&resize=700%2C400 2x"},"classes":[]},{"id":871,"url":"https:\/\/www.cosmoespai.com\/cat\/sagitari-a-el-forat-negre-del-centre-de-la-via-lactia\/","url_meta":{"origin":602,"position":4},"title":"Sagitari A*: el forat negre del centre de la Via L\u00e0ctia","author":"Ferran","date":"12 de mar\u00e7 de 2023","format":false,"excerpt":"Sagitari A*, pronunciat \u00abSagitari A estrella\u00bb i abreviat Sgr A*, \u00e9s un forat negre supermassiu que es troba al centre de la nostra gal\u00e0xia, la Via L\u00e0ctia. \u00c9s una font d\u2019ones r\u00e0dio molt compacta i brillant. Durant molt de temps s\u2019havia suposat que es tractava d\u2019un forat negre, per\u00f2 aix\u00f2\u2026","rel":"","context":"A &quot;General&quot;","block_context":{"text":"General","link":"https:\/\/www.cosmoespai.com\/cat\/category\/general\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2023\/03\/SagitariA.jpg?fit=720%2C405&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2023\/03\/SagitariA.jpg?fit=720%2C405&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2023\/03\/SagitariA.jpg?fit=720%2C405&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2023\/03\/SagitariA.jpg?fit=720%2C405&resize=700%2C400 2x"},"classes":[]},{"id":652,"url":"https:\/\/www.cosmoespai.com\/cat\/per-que-fa-mes-calor-a-lequador-que-als-pols\/","url_meta":{"origin":602,"position":5},"title":"Per qu\u00e8 fa m\u00e9s calor a l\u2019equador que als pols?","author":"Ferran","date":"19 de juny de 2022","format":false,"excerpt":"Un error com\u00fa \u00e9s pensar que fa m\u00e9s calor a l\u2019equador perqu\u00e8 es troba m\u00e9s a prop del Sol que altres zones de la Terra. No obstant, la dist\u00e0ncia que separa l\u2019equador dels pols \u00e9s tant petita, en comparaci\u00f3 a l\u2019enorme dist\u00e0ncia que separa la Terra del Sol, (150 000\u2026","rel":"","context":"A &quot;La Terra&quot;","block_context":{"text":"La Terra","link":"https:\/\/www.cosmoespai.com\/cat\/category\/sistema-solar\/la-terra\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2022\/06\/Temperatura_Equador-1.jpg?fit=720%2C405&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2022\/06\/Temperatura_Equador-1.jpg?fit=720%2C405&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2022\/06\/Temperatura_Equador-1.jpg?fit=720%2C405&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.cosmoespai.com\/cat\/wp-content\/uploads\/2022\/06\/Temperatura_Equador-1.jpg?fit=720%2C405&resize=700%2C400 2x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/www.cosmoespai.com\/cat\/wp-json\/wp\/v2\/posts\/602"}],"collection":[{"href":"https:\/\/www.cosmoespai.com\/cat\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cosmoespai.com\/cat\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cosmoespai.com\/cat\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cosmoespai.com\/cat\/wp-json\/wp\/v2\/comments?post=602"}],"version-history":[{"count":2,"href":"https:\/\/www.cosmoespai.com\/cat\/wp-json\/wp\/v2\/posts\/602\/revisions"}],"predecessor-version":[{"id":605,"href":"https:\/\/www.cosmoespai.com\/cat\/wp-json\/wp\/v2\/posts\/602\/revisions\/605"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.cosmoespai.com\/cat\/wp-json\/wp\/v2\/media\/604"}],"wp:attachment":[{"href":"https:\/\/www.cosmoespai.com\/cat\/wp-json\/wp\/v2\/media?parent=602"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cosmoespai.com\/cat\/wp-json\/wp\/v2\/categories?post=602"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cosmoespai.com\/cat\/wp-json\/wp\/v2\/tags?post=602"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}