study published in Nature,<\/a> describes the system he spent months analyzing as \u201csuper weird\u201d compared to our own.<\/p>\nThe biggest object in this young system is the star CD-35 2722, which has about half the mass of the Sun. The star is being orbited by a brown dwarf, an object too massive to be a planet but too small to be a star. This brown dwarf has a satellite, which we usually call a moon, but in this case it\u2019s about as big as Jupiter.<\/p>\n
\u201cThis system is somewhat hard to define using Solar-System-based words like \u2018planet\u2019 and \u2018moon,\u2019\u201d states Hoy, who is also affiliated with the Universidad Diego Portales and YEMS, a multidisciplinary research center focused on detecting exoplanets and exomoons.<\/p>\n
Hoy and his co-authors have settled on the most technical terminology available, and called the third-order object an \u201cexosatellite.\u201d<\/p>\n
\u201cThe exosatellite is clearly massive enough to be a planet, but it does not orbit a star, though it orbits an object that orbits a star,\u201d says Hoy. \u201cBeing the third wheel in this system makes us want to call it a moon, even if it\u2019s nothing like the small, rocky moons we have in our system.\u201d<\/p>\n
\u201cWe have a clear delineation between the planets and the Sun in the Solar System, so defining things like moons is simple,\u201d adds Alice Zurlo, YEMS Director and collaborator on the study.<\/p>\n
\u201cIn the CD-35 2722 system, where we are blurring the lines between stars, planets, and moons, the whole thing becomes more complicated to describe.\u201d<\/p>\n
MORE FIRSTS IN SPACE:<\/p>\n
Regardless of what to call this object, astronomers have been trying to detect satellites outside our Solar System for years, but none has yet been confidently detected. Therefore, despite the over 6,000 exoplanets discovered to date, only a few exomoon candidates have been spotted and the evidence to support them is limited.<\/p>\n
For the CD-35 2722 observations, Hoy, Zurlo, and their team used the CRIRES+ instrument on the VLT, employing the method that was used to find the first exoplanet around a Sun-like star.<\/p>\n
They applied this radial velocity method to detect small wobbles on the brown dwarf caused by the gravity of the object orbiting it, finding what the team believe to be strong evidence for this \u2018moon.\u2019<\/p>\n
\u00a0<\/p>\n
\u201cThis system is truly unique and represents a breakthrough: the first plausible detection of an exosatellite,\u201d says Zurlo confidently.<\/p>\n
Like Wolszczan\u2019s, the detection could herald a rapid acceleration in the identification of exosatellites\/moons. 6 of the 8 planets in our solar system have natural moons, so they should be fairly common in the universe. The issue is that they\u2019re small. Our Moon is quite small compared to Earth, but Phobos, the largest satellite of Mars, is just 7 miles across.<\/p>\n
SHARE This Brilliant Science And The Breakthrough It Portends In Moonspotting\u2026<\/p>\n","protected":false},"excerpt":{"rendered":"Artist\u2019s impression of the CD-35 2722 system \u2013 credit, ESO\/M. Kornmesser As soon as Aleksander Wolszczan confirmed the…\n","protected":false},"author":2,"featured_media":715898,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[1813,59,90,416,56,54,55],"class_list":["post-715897","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-astronomy","tag-gb","tag-science","tag-space","tag-uk","tag-united-kingdom","tag-unitedkingdom"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts\/715897","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/comments?post=715897"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts\/715897\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/media\/715898"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/media?parent=715897"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/categories?post=715897"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/tags?post=715897"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
![\"\"](\"https:\/\/www.newsbeep.com\/uk\/wp-content\/uploads\/2026\/07\/Artists-impression-of-the-CD-35-2722-system.jpg\")
Artist\u2019s impression of the CD-35 2722 system \u2013 credit, ESO\/M. Kornmesser<\/p>\n