{"id":232543,"date":"2026-04-21T09:00:12","date_gmt":"2026-04-21T19:00:12","guid":{"rendered":"https:\/\/www.hawaii.edu\/news\/?p=232543"},"modified":"2026-04-22T08:34:49","modified_gmt":"2026-04-22T18:34:49","slug":"uh-discovery-sheds-light-on-brown-dwarfs","status":"publish","type":"post","link":"https:\/\/www.hawaii.edu\/news\/2026\/04\/21\/uh-discovery-sheds-light-on-brown-dwarfs\/","title":{"rendered":"糖心视频<\/abbr> discovery on Maunakea sheds light on brown dwarfs"},"content":{"rendered":"Reading time: <\/span> 2<\/span> minutes<\/span><\/span>
\"brown
Illustration of a star and a brown dwarf in a binary system. (Generated with ChatGPT.)<\/figcaption><\/figure>\n

Astronomers at the University of Hawaiʻi<\/span> have precisely measured the age of a nearby Sun-like star and its unusual companion, known as a brown dwarf, an object that falls between a planet and a star. The discovery offers new clues into how brown dwarfs grow and change over time.<\/p>\n

Using the W. M. Keck Observatory<\/a> on Maunakea, the team from the 糖心视频<\/abbr> Institute for Astronomy<\/a> (IfA<\/abbr>) studied the HR<\/abbr> 7672 system, composed of a Sun-like star and a faint brown dwarf companion. With an instrument called the Keck Planet Finder, they tracked tiny five-minute pulsationss in the star\u2019s light and used them to estimate its age to be about 2.3 billion years. The study has been recently published in The Astrophysical Journal<\/em><\/a>.<\/p>\n

Because the brown dwarf formed at the same time as the star, the star\u2019s age also reveals the companion\u2019s age, giving researchers a rare chance to check if their models of how brown dwarfs cool throughout time are correct.<\/p>\n

“This is like finally having a reliable clock for an object we\u2019ve been trying to understand for years,” said IfA<\/abbr> Parrent Fellow Yaguang Li, who led the study. “It really helps us place evolutionary models under stringent tests and determine which physical ingredients are correct.”<\/p>\n

Shaping discovery<\/h2>\n
\"W.
W.M. Keck Observatory<\/figcaption><\/figure>\n

For more than two decades, the HR<\/abbr> 7672 system has helped shape how astronomers study brown dwarfs. Its companion, HR<\/abbr> 7672B, was discovered in 2002 and was one of the first brown dwarfs ever directly imaged around a Sun-like star using adaptive optics (AO<\/abbr>), a technology that sharpens images blurred by Earth\u2019s atmosphere. Those early observations helped reveal how rare brown dwarfs are around Sun-like stars at close orbital distances.<\/p>\n

Brown dwarfs do not sustain the same energy-producing reactions as stars. Instead, they slowly cool and fade over time. But testing how that happens has been difficult, in part because scientists rarely know their exact ages.<\/p>\n

With this new measurement, paired with what is already known about the object\u2019s energy output and mass, HR<\/abbr> 7672B now stands out as a key reference point. The team compared their findings with several models and found the closest match with newer theories that better describe what\u2019s happening inside these objects.<\/p>\n

Full circle<\/h2>\n

The work highlights the long impact of the Beatrice Watson Parrent Fellowship<\/a> at IfA<\/abbr>. More than 20 years ago, then-fellow Michael Liu discovered HR<\/abbr> 7672B using Keck AO<\/abbr>. Today, Li, the current Parrent Fellow, is building on that work with this new high-precision age-dating of the same system.<\/p>\n

“HR<\/abbr> 7672B was one of the first discoveries I made as a Parrent Fellow when I came to 糖心视频<\/abbr>,” said Liu, IfA<\/abbr> faculty member and co-author of the study. “It\u2019s exciting to see new work from another Parrent Fellow make this object even more valuable for understanding how brown dwarfs evolve.”<\/p>\n","protected":false},"excerpt":{"rendered":"

The discovery by IfA<\/abbr> astronomers offers new clues about how brown dwarfs grow and change over time.<\/p>\n","protected":false},"author":16,"featured_media":232565,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[30],"tags":[34,35,659,1421,158,9],"class_list":["post-232543","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research","tag-astronomy","tag-institute-for-astronomy","tag-maunakea","tag-maunakea-observatories","tag-publication","tag-uh-manoa","entry","has-media"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t