{"id":19172,"date":"2024-09-27T06:51:43","date_gmt":"2024-09-27T01:21:43","guid":{"rendered":"https:\/\/vajiramandravi.com\/current-affairs\/?p=19172"},"modified":"2025-10-10T14:27:46","modified_gmt":"2025-10-10T08:57:46","slug":"spiral-galaxy","status":"publish","type":"post","link":"https:\/\/vajiramandravi.com\/current-affairs\/spiral-galaxy\/","title":{"rendered":"What is a Spiral Galaxy?"},"content":{"rendered":"<h2><strong>About Spiral Galaxy:<\/strong><\/h2>\n<ul>\n<li>Spiral galaxies are <strong>twisted collections of stars and gas<\/strong> that often have beautiful shapes and are <strong>made up of hot, young stars.<\/strong><\/li>\n<li>In a spiral galaxy, the <strong>stars, gas, and dust<\/strong> are <strong>gathered in spiral arms<\/strong> that spread outward from the galaxy&#8217;s center.\u00a0<\/li>\n<li><strong>Most of the galaxies<\/strong> that scientists have discovered so far <strong>are spiral galaxies,<\/strong> as opposed to the other two main categories of galaxy shapes\u2014elliptical and irregular.<\/li>\n<li>Approximately <strong>60% of all galaxies<\/strong> are thought to be spiral galaxies.<\/li>\n<li>The <strong>Milky Way<\/strong>, the galaxy that includes Earth and our solar system, <strong>is an example<\/strong> of a spiral galaxy.<\/li>\n<li><strong>Structure:<\/strong>\n<ul>\n<li>Most spiral galaxies contain a <strong>central bulge surrounded by a flat, rotating disk of stars.\u00a0<\/strong><\/li>\n<li>The <strong>bulge<\/strong> in the center is <strong>made up of older, dimmer stars<\/strong> and is thought to <strong>contain a supermassive black hole.<\/strong><\/li>\n<li>Approximately <strong>two-thirds of spiral galaxies<\/strong> also contain a bar structure through their center, as does the Milky Way.\u00a0<\/li>\n<li>The disk of stars orbiting the bulge separates into arms that circle the galaxy.<\/li>\n<li>These spiral arms contain a wealth of gas and dust and younger stars that shine brightly before their quick demise.<\/li>\n<\/ul>\n<\/li>\n<li>The <strong>majority of spiral galaxies rotate<\/strong> in the sense that the arms trail the direction of the spin.\u00a0<\/li>\n<li>The <strong>visible portion<\/strong> of spiral galaxies <strong>contains only a small fraction of the total mass<\/strong> of the galaxy, and that spiral galaxies are <strong>surrounded by an extensive haloconsisting<\/strong> mostly <strong>of dark matter.<\/strong><\/li>\n<li>Spiral galaxies are thought to <strong>evolve into elliptical galaxies as the spirals get older<\/strong>.\u00a0<\/li>\n<\/ul>\n<hr \/>\n<h3><strong>Q1<\/strong>: What is a Black Hole?<\/h3>\n<p>A black hole is a region in space where gravity pulls so much that even light cannot get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying. Because no light can get out, it is difficult to detect a black hole. The largest black holes are called &#8220;supermassive.&#8221; These black holes have masses that are more than 1 million suns together.<\/p>\n<p><strong>Source: <\/strong><a href=\"https:\/\/www.livemint.com\/science\/news\/spiral-galaxy-59-million-light-years-away-looks-like-this-nasa-shares-stunning-video-of-young-hot-stars-11727161312951.html\" target=\"_blank\" rel=\"nofollow noopener\">Spiral galaxy 59 million light-years away looks like this: NASA shares stunning video of \u2019young, hot stars\u2019<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Spiral galaxies are twisted collections of stars and gas that often have beautiful shapes and are made up of hot, young stars. <\/p>\n","protected":false},"author":5,"featured_media":19173,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[],"class_list":{"0":"post-19172","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-upsc-prelims-current-affairs","8":"no-featured-image-padding"},"acf":[],"_links":{"self":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/posts\/19172","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/comments?post=19172"}],"version-history":[{"count":0,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/posts\/19172\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/media\/19173"}],"wp:attachment":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/media?parent=19172"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/categories?post=19172"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/tags?post=19172"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}