The Milky Way is populated by at least 100 billion stars. Less than 10 of these belong to the WO2 spectral class. These are highly evolved stars that are in the last stages of the nuclear fusion process: they have in fact finished burning all their available hydrogen and, in some cases, even helium.
The most studied star of class WO2 is WR 102, located 9500 light years away from Earth, in the constellation Sagittarius.
Like all other stars in this class, WR 102 is extremely hot and bright. Its brightness is in fact more than 300,000 times greater than that of the Sun and its surface temperature is 210,000 Kelvin, the highest ever recorded in a stellar atmosphere!
The star currently has a mass of 16 solar masses, but this value decreases from year to year as WR 102 ejects a large amount of material into space in the form of stellar wind.
The incredible thing is that this extreme star is smaller than the Sun: its diameter is in fact equal to just 60% of the solar diameter!
A star like WR 102 that has already finished burning hydrogen hasn’t long life: it has been calculated that the star will explode and become a supernova in just 1500 years.
Gerd Dani — Founder & Director Gerd Dani is the visionary in a wheelchair behind FreeAstroScience. An astronomy graduate and a master's in physics, he founded this blog in June 2020, driven by a passion for breaking down complex scientific and philosophical concepts into bite-sized, digestible pieces. As President, he is dedicated to making science accessible to everyone, from students to seasoned academics.
(()=>{async function handleCredentialResponse(response){try{const res=await fetch('https://freeastroscience.com/wp-login.php?action=googlesitekit_auth',{method:'POST',headers:{'Content-Type':'application/x-www-form-urlencoded'},body:new URLSearchParams(response)});/* Preserve comment text in case of redirect after login on a page with a Sign in with Google button in the WordPress comments. */ const commentText=document.querySelector('#comment')?.value;const postId=document.querySelectorAll('.googlesitekit-sign-in-with-google__comments-form-button')?.[0]?.className?.match(/googlesitekit-sign-in-with-google__comments-form-button-postid-(\d+)/)?.[1];if(!! commentText?.length){sessionStorage.setItem(`siwg-comment-text-${postId}`,commentText);}location.reload();}catch(error){console.error(error);}}if(typeof google !=='undefined'){google.accounts.id.initialize({client_id:'251104905146-eghigrtua82ec7aan4em9fle9u5f0ilc.apps.googleusercontent.com',callback:handleCredentialResponse,library_name:'Site-Kit'});}const defaultButtonOptions={"theme":"outline","text":"signin_with","shape":"rectangular"};document.querySelectorAll('.googlesitekit-sign-in-with-google__frontend-output-button').forEach((siwgButtonDiv)=>{const buttonOptions={shape:siwgButtonDiv.getAttribute('data-googlesitekit-siwg-shape')|| defaultButtonOptions.shape,text:siwgButtonDiv.getAttribute('data-googlesitekit-siwg-text')|| defaultButtonOptions.text,theme:siwgButtonDiv.getAttribute('data-googlesitekit-siwg-theme')|| defaultButtonOptions.theme,};if(typeof google !=='undefined'){google.accounts.id.renderButton(siwgButtonDiv,buttonOptions);}});/* If there is a matching saved comment text in sessionStorage,restore it to the comment field and remove it from sessionStorage. */ const postId=document.body.className.match(/postid-(\d+)/)?.[1];const commentField=document.querySelector('#comment');const commentText=sessionStorage.getItem(`siwg-comment-text-${postId}`);if(commentText?.length && commentField && !! postId){commentField.value=commentText;sessionStorage.removeItem(`siwg-comment-text-${postId}`);}})();
var astra = {"break_point":"921","isRtl":"","is_scroll_to_id":"1","is_scroll_to_top":"1","is_header_footer_builder_active":"1","responsive_cart_click":"flyout","is_dark_palette":"","revealEffectEnable":"","edit_post_url":"https://freeastroscience.com/wp-admin/post.php?post={{id}}&action=edit","ajax_url":"https://freeastroscience.com/wp-admin/admin-ajax.php","infinite_count":"2","infinite_total":"0","pagination":"number","infinite_scroll_event":"scroll","no_more_post_message":"No more posts to show.","grid_layout":{"desktop":3,"tablet":1,"mobile":1},"site_url":"https://freeastroscience.com","blogArchiveTitleLayout":"layout-2","blogArchiveTitleOn":"1","show_comments":"Show Comments","enableHistoryPushState":"1","masonryEnabled":"","blogMasonryBreakPoint":"0"};
//# sourceURL=astra-theme-js-js-extra
The Milky Way is populated by at least 100 billion stars. Less than 10 of these belong to the WO2 spectral class. These are highly evolved stars that are in the last stages of the nuclear fusion process: they have in fact finished burning all their available hydrogen and, in some cases, even helium.
