{"id":684265,"date":"2026-03-26T23:54:25","date_gmt":"2026-03-26T23:54:25","guid":{"rendered":"https:\/\/www.europesays.com\/us\/684265\/"},"modified":"2026-03-26T23:54:25","modified_gmt":"2026-03-26T23:54:25","slug":"apod-2026-march-26-black-holes-and-neutron-stars-218-mergers-and-counting","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/us\/684265\/","title":{"rendered":"APOD: 2026 March 26 \u2013 Black Holes and Neutron Stars: 218 Mergers and Counting"},"content":{"rendered":"

APOD: 2026 March 26 \u2013 Black Holes and Neutron Stars: 218 Mergers and Counting<\/p>\n

Discover the cosmos!<\/a>
\nEach day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.\n<\/p>\n

2026 March 26
\n

\n\"218<\/a>\n<\/p>\n

Black Holes and Neutron Stars: 218 Mergers and Counting <\/b>
Image Credit: <\/b>
\nRyan Nowicki<\/a>, Bill Smith<\/a> & Karan Jani<\/a><\/p>\n

Text:
\nCecilia Chirenti<\/a>
\n(NASA<\/a>
\nGSFC<\/a>,
\nUMCP<\/a>,
\nCRESST II<\/a>)<\/p>\n

Explanation: <\/b>
\nWhat is the sound<\/a> of two black holes merging in deep space?<\/p>\n

Sound waves<\/a> don’t propagate in vacuum, but gravitational waves<\/a> do.<\/p>\n

In 2015 we were able to “hear” them for the first time<\/a> and confirm one of Albert Einstein<\/a>‘s theoretical predictions.<\/p>\n

Each square<\/a> on the grid<\/a> of the featured image<\/a> represents one of the gravitational wave detections announced so far<\/a> by the LIGO<\/a>–VIRGO<\/a>–KAGRA<\/a> Collaboration<\/a>.<\/p>\n

These plots show how the binary pair accelerates in their orbit<\/a> around each other towards merger: the rising frequency effect is called a “chirp<\/a>“.<\/p>\n

Although there are significantly more neutron stars<\/a> than black holes<\/a>, most of the detections<\/a> are binary black hole mergers.<\/p>\n

That happens because black holes are heavier<\/a> and their signals are louder and can be seen farther away, resulting in more detections.<\/p>\n

These events are rare<\/a>, and we don’t expect to see one close by in our Galaxy<\/a> any time soon.<\/p>\n

But they are happening continuously<\/a> throughout the cosmos.\n<\/p>\n

Tomorrow’s picture: <\/b>compact galaxy group<\/a> <\/p>\n

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\n Authors & editors: <\/b>
\nRobert Nemiroff<\/a>
\n(MTU<\/a>) &
\nJerry Bonnell<\/a> (UMCP<\/a>)
NASA Official: <\/b> Amber Straughn
\nSpecific rights apply<\/a>.
NASA Web Privacy<\/a>,
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A service of:<\/b>
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\nNASA<\/a> \/
\nGSFC<\/a>,
\n
NASA Science Activation<\/a>
\n
&<\/b> Michigan Tech. U.<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"APOD: 2026 March 26 \u2013 Black Holes and Neutron Stars: 218 Mergers and Counting Discover the cosmos! Each…\n","protected":false},"author":3,"featured_media":684266,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_share_on_mastodon":"0"},"categories":[25],"tags":[5163,22632,45484,57861,492,159,67,132,68],"class_list":["post-684265","post","type-post","status-publish","format-standard","has-post-thumbnail","category-physics","tag-black-holes","tag-gravitational-waves","tag-ligo","tag-mergers","tag-physics","tag-science","tag-united-states","tag-unitedstates","tag-us"],"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@us\/116298177797859940","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/684265","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/comments?post=684265"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/684265\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media\/684266"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media?parent=684265"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/categories?post=684265"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/tags?post=684265"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}