{"id":610717,"date":"2026-09-09T13:26:16","date_gmt":"2026-09-09T13:26:16","guid":{"rendered":"https:\/\/www.newsbeep.com\/il\/610717\/"},"modified":"2026-09-09T13:26:16","modified_gmt":"2026-09-09T13:26:16","slug":"apod-2026-september-9-witness-xz-andromedae-wink","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/il\/610717\/","title":{"rendered":"APOD: 2026 September 9 &#8211; Witness XZ Andromedae Wink"},"content":{"rendered":"<p class=\"p-md margin-0 media-detail-hero__description\">\n\t\t\t\t\t\t\tExplanation: Is this star winking at us? The central object in <a href=\"https:\/\/app.astrobin.com\/u\/OgetayKayali?i=r3zngj&amp;r=B\" rel=\"nofollow noopener\" target=\"_blank\">today\u2019s animation<\/a> is not one but two stars. XZ Andromedae, indicated by the bold lines, is an <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Algol-type_variable_binary_star_animation_3.gif\" rel=\"nofollow noopener\" target=\"_blank\">Algol-type<\/a> <a href=\"https:\/\/science.nasa.gov\/citizen-science\/eclipsing-binary-patrol\/\" rel=\"nofollow noopener\" target=\"_blank\">eclipsing binary<\/a> with a nearly edge-on orbit from Earth\u2019s perspective. The bottom <a href=\"https:\/\/imagine.gsfc.nasa.gov\/science\/toolbox\/timing1.html\" rel=\"nofollow noopener\" target=\"_blank\">light curve<\/a> shows the amount of light from the system dim and brighten as the cooler star eclipses its hotter, brighter companion. Analysis of several XZ Andromedae light curves indicates <a href=\"https:\/\/arxiv.org\/pdf\/1904.07373\" rel=\"nofollow noopener\" target=\"_blank\">there may be two other stars<\/a> orbiting the system. This particular light curve was created with <a href=\"https:\/\/github.com\/OgetayKayali\/citizen-astronomy\" rel=\"nofollow noopener\" target=\"_blank\">Citizen Astronomy<\/a>, an <a href=\"https:\/\/opensource.org\/osd\" rel=\"nofollow noopener\" target=\"_blank\">open-source software<\/a> for <a href=\"https:\/\/boyce-astro.org\/differential-photometry\/\" rel=\"nofollow noopener\" target=\"_blank\">differential photometry<\/a>. The software takes the difference in brightness between a target and comparison star and traces its behavior over time. This technique reduces most variations from the instrument and Earth\u2019s atmosphere. In addition to eclipsing binaries, this analysis is useful for studying <a href=\"https:\/\/science.nasa.gov\/exoplanets\/whats-a-transit\/\" rel=\"nofollow noopener\" target=\"_blank\">transiting exoplanets<\/a>, <a href=\"https:\/\/science.nasa.gov\/image-article\/apod-2024-june-16-animation-black-hole-destroys-star\/\" rel=\"nofollow noopener\" target=\"_blank\">accreting black holes<\/a>, <a href=\"https:\/\/science.nasa.gov\/image-article\/apod-2016-february-9-the-rise-and-fall-of-supernova-2015f\/\" rel=\"nofollow noopener\" target=\"_blank\">supernovae<\/a>, and many more time-varying astronomical phenomena. Astrophotographers: try it out on your own data!<\/p>\n<p>APOD&#8217;s main NASA site is\u00a0<a href=\"https:\/\/asterisk.apod.com\/viewtopic.php?t=45023\" rel=\"nofollow noopener\" target=\"_blank\">moving<\/a>:\u00a0From\u00a0<a href=\"https:\/\/apod.nasa.gov\/\" rel=\"nofollow noopener\" target=\"_blank\">apod.nasa.gov<\/a>\u00a0to\u00a0<a href=\"https:\/\/science.nasa.gov\/apod\" rel=\"nofollow noopener\" target=\"_blank\">science.nasa.gov\/apod<\/a><br \/>Tomorrow&#8217;s picture: potentially a giraffe\t\t\t\t\t\t<\/p>\n","protected":false},"excerpt":{"rendered":"Explanation: Is this star winking at us? The central object in today\u2019s animation is not one but two&hellip;\n","protected":false},"author":2,"featured_media":610718,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[257340,85,46,141,145],"class_list":["post-610717","post","type-post","status-publish","format-standard","has-post-thumbnail","category-space","tag-apod","tag-il","tag-israel","tag-science","tag-space"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/610717","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/comments?post=610717"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/610717\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media\/610718"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media?parent=610717"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/categories?post=610717"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/tags?post=610717"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}