{"id":790051,"date":"2024-10-08T07:16:52","date_gmt":"2024-10-08T12:16:52","guid":{"rendered":"http:\/\/spaceweekly.com\/?p=790051"},"modified":"2024-10-08T07:16:52","modified_gmt":"2024-10-08T12:16:52","slug":"is-this-white-dwarf-exoplanet-a-preview-of-earths-fate","status":"publish","type":"post","link":"https:\/\/spaceweekly.com\/?p=790051","title":{"rendered":"Is this white dwarf exoplanet a preview of Earth\u2019s fate?"},"content":{"rendered":"<p> <br \/>\n<\/p>\n<div>\n<p><iframe loading=\"lazy\" title=\"Red giant animation\" width=\"1110\" height=\"624\" src=\"https:\/\/www.youtube.com\/embed\/iJVfR_MSZ7Q?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><br \/><em>This video depicts a possible fate for Earth when the sun expands into a red giant star. If the red giant sheds its mass quickly enough to allow Earth to migrate to a wider orbit, our planet will escape being engulfed by the expanding surface of the red giant. A newly-discovered white dwarf exoplanet seems to have done exactly that. Video via Adam Makarenko\/ UC Berkeley\/ YouTube (Creative Commons Attribution License, reuse allowed).<\/em><\/p>\n<p>Our fall fund-raiser is going on now. Please help EarthSky keep going. Donate to EarthSky today!<\/p>\n<ul>\n<li><strong>White dwarf stars are the remaining small, hot cores of dead stars<\/strong>. They form after a star expands into a red giant, then contracts back into a white dwarf.<\/li>\n<li><strong>Planets orbiting close to their stars would be consumed<\/strong> in the red giant phase. But could Earth escape when the sun becomes a red giant billions of years from now?<\/li>\n<li><strong>Astronomers discovered an Earth-sized exoplanet orbiting a white dwarf<\/strong> 4,000 light-years away. Its survival could mean that Earth might escape its fiery fate as well.<\/li>\n<\/ul>\n<h3>Earth-sized exoplanet orbiting a white dwarf star<\/h3>\n<p>Scientists say that about 5 billion years from now, the sun will become a red giant star. It will consume Mercury, Venus \u2026 and probably Earth. And then it will shrink to a tiny white dwarf star as it dies. But the discovery of an Earth-sized planet orbiting a white dwarf 4,000 light-years away shows that Earth might actually be able to survive this fiery fate.<\/p>\n<p>A team of astronomers, led by the University of California (UC) Berkeley, found the planet using the W. M. Keck Observatory on Maunakea, Hawaii Island. Lead author Keming Zhang and his colleagues published their peer-reviewed findings in <em>Nature Astronomy<\/em> on September 26, 2024. You can also read the free preprint on arXiv. Zhang was formerly at UC Berkeley in California, and now is at UC San Diego.<\/p>\n<h3>White dwarf exoplanet: Earth\u2019s future?<\/h3>\n<p>The rocky planet is about the size of Earth, and orbits a white dwarf star 4,000 light-years away, close to the central bulge of our galaxy. A white dwarf is the remaining burned-out core of a dead star. So this star will have swelled into a red giant first before entering this white dwarf phase.<\/p>\n<p>In most scenarios, the Earth-sized planet should have been consumed and destroyed by the red giant. But it\u2019s still there. Does that mean Earth could also escape a cataclysmic fate?<\/p>\n<h3>Could Earth move out to safety?<\/h3>\n<p>According to the researchers, there\u2019s a chance. As our sun expands, it will also shed its mass. That means its gravitational attraction would lessen. The researchers noted that, if our sun sheds this mass quickly enough, it could have the effect of releasing Earth into a more distant orbit. And this could be the difference between being engulfed by the growing sun and remaining scorched but intact.<\/p>\n<p>The researchers calculated that, in this scenario, Earth\u2019s new orbit may be about twice the size it is now. And, interestingly, the newly-discovered planet is in an orbit about twice the size of Earth\u2019s. <\/p>\n<p>It may be a slim chance of survival, but it is possible. Earth would still no longer habitable for life itself as we know it now, but the planet itself would still exist. Lu added:<\/p>\n<blockquote>\n<p>Whether life can survive on Earth through that (red giant) period is unknown. But certainly the most important thing is that Earth isn\u2019t swallowed by the Sun when it becomes a red giant. This system that Keming found is an example of a planet \u2013 probably an Earth-like planet originally on a similar orbit to Earth \u2013 that survived its host star\u2019s red giant phase.<\/p>\n<\/blockquote>\n<h3>Microlensing discovery<\/h3>\n<p>Astronomers first detected this planetary system back in 2020. They found it using the microlensing technique. That was when the white dwarf passed in front of a more distant star. The white dwarf magnified the background star\u2019s light by 1,000 times. How does that happen? In microlensing, the gravity of the closer star acts like a lens, which focuses and amplifies the light from the more distant star.<\/p>\n<p>The researchers called this particular microlensing event KMT-2020-BLG-0414. They used the Korea Microlensing Telescope Network (KMTNet) in the Southern Hemisphere to detect it, hence \u201cKMT.\u201d<\/p>\n<p>The astronomers re-examined the system in 2023. This time, they used Keck Observatory\u2019s second-generation Near-Infrared Camera (NIRC2), along with the adaptive optics system. This allowed them to eliminate the blur caused by Earth\u2019s atmosphere.<\/p>\n<h3>Regular star or white dwarf?<\/h3>\n<p>If the star was a regular star, then it should have been seen in the Keck images. But the astronomers saw nothing. This led them to conclude that the star was actually a white dwarf. Zhang said:<\/p>\n<blockquote>\n<p>Our conclusions are based on ruling out the alternative scenarios, since a normal star would have been easily seen. Because the lens is both dark and low mass, we concluded that it can only be a white dwarf.<\/p>\n<\/blockquote>\n<p>Co-author Jessica Lu at UC Berkeley added:<\/p>\n<blockquote>\n<p>This is a case of where seeing nothing is actually more interesting than seeing something,\u201d said Lu, who looks for microlensing events caused by free-floating stellar-mass black holes in the Milky Way.<\/p>\n<\/blockquote>\n<p>UC Berkeley astronomer Joshua Bloom also said:<\/p>\n<blockquote>\n<p>Microlensing has turned into a very interesting way of studying other star systems that can\u2019t be observed and detected by the conventional means, i.e. the transit method or the radial velocity method. There is a whole set of worlds that are now opening up to us through the microlensing channel, and what\u2019s exciting is that we\u2019re on the precipice of finding exotic configurations like this.<\/p>\n<\/blockquote>\n<figure id=\"attachment_489129\" aria-describedby=\"caption-attachment-489129\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><figcaption id=\"caption-attachment-489129\" class=\"wp-caption-text\">View larger. | Artist\u2019s concept of an Earth-like planet orbiting a white dwarf star. Could Earth also survive our sun\u2019s future red giant phase? Image via Adam Makarenko\/ W. M. Keck Observatory.<\/figcaption><\/figure>\n<p>Bottom line: Astronomers have discovered an Earth-sized planet orbiting a white dwarf star. Does this white dwarf exoplanet mean Earth could survive the death of the sun?<\/p>\n<p>Source: An Earth-mass planet and a brown dwarf in orbit around a white dwarf<\/p>\n<p>Source (preprint): An Earth-Mass Planet and a Brown Dwarf in Orbit Around a White Dwarf<\/p>\n<p>Via W. M. Keck Observatory<\/p>\n<p>Read more: Giant planets orbiting white dwarfs: 1st images?<\/p>\n<p>Read more: Solar system\u2019s future seen: 1st planet around a white dwarf<\/p>\n<p><span class=\"cp-load-after-post\"\/><\/div>\n<div>\n<div class=\"post-author\">\n<h4>Paul Scott Anderson<\/h4>\n<p>                    View Articles\n                  <\/p><\/div>\n<div class=\"post-tags\">\n<h6 data-udy-fe=\"text_7c58270d\">About the Author:<\/h6>\n<p>Paul Scott Anderson has had a passion for space exploration that began when he was a child when he watched Carl Sagan\u2019s Cosmos. He studied English, writing, art and computer\/publication design in high school and college. He later started his blog The Meridiani Journal in 2005, which was later renamed Planetaria. He also later started the blog Fermi Paradoxica, about the search for life elsewhere in the universe.&#13;<br \/>\n&#13;<br \/>\nWhile interested in all aspects of space exploration, his primary passion is planetary science and SETI. In 2011, he started writing about space on a freelance basis with Universe Today. He has also written for SpaceFlight Insider and AmericaSpace and has also been published in The Mars Quarterly. He also did some supplementary writing for the iOS app Exoplanet.&#13;<br \/>\n&#13;<br \/>\nHe has been writing for EarthSky since 2018, and also assists with proofing and social media.<\/p>\n<\/p><\/div>\n<\/p><\/div>\n<p><br \/>\n<br \/><a href=\"https:\/\/earthsky.org\/space\/white-dwarf-exoplanet-white-dwarfs-red-giants-exoplanets-earth\/?rand=772280\">Source link <\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>This video depicts a possible fate for Earth when the sun expands into a red giant star. If the red giant sheds its mass quickly enough to allow Earth to&hellip; <\/p>\n","protected":false},"author":1,"featured_media":790052,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[46],"tags":[],"class_list":["post-790051","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-earth-sky"],"_links":{"self":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts\/790051","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=790051"}],"version-history":[{"count":0,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts\/790051\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/media\/790052"}],"wp:attachment":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=790051"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=790051"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=790051"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}