![\"An](\"https:\/\/www.newsbeep.com\/nz\/wp-content\/uploads\/2025\/12\/image-5.png\")
An image of the Milky Way showing the location of the first two black holes discovered by Gaia including Gaia BH2 which has a red giant companion.\u00a0(Image credit: ESA\/Gaia\/DPAC; CC BY-SA 3.0 IGO, CC BY-SA 3.0 IGO)<\/p>\n
The red giant in question, located in the Gaia BH2 system, has been studied for these exact oscillations. The data collected by TESS reveals the star\u2019s internal composition and how it behaves under the gravitational pull of its black hole companion. The result? A star that has a far more complex history than astronomers originally anticipated. Hey continued, \u201cThese vibrations told us something unexpected about this star\u2019s history,\u201d indicating that the star\u2019s evolutionary path is anything but straightforward.<\/p>\n
The Unexpected History of Gaia BH2\u2019s Red Giant Star<\/p>\n
The red giant star in the Gaia BH2 system, which once lived as a relatively stable star, has gone through a series of turbulent changes. Red giants are typically older stars that have exhausted the fuel in their cores for nuclear fusion. However, the star in Gaia BH2 is much younger than expected\u2014only about 5 billion years old. This age, paired with the star\u2019s unusual chemical composition, raises intriguing questions. The star\u2019s high abundance of heavy elements, particularly \u201calpha-rich\u201d elements, is typically seen in older stars. Yet this red giant is still in its early phase, much younger than similar stars observed in isolation.<\/p>\n
According to Hey, \u201cYoung, alpha-rich stars are quite rare and puzzling,\u201d and the combination of youthful age and ancient chemistry suggests that the star\u2019s story is far from typical. The star likely didn\u2019t evolve in isolation. Rather, it most likely acquired extra mass from a companion, either through a merger or by absorbing material when the black hole in the system formed. This process would have fundamentally altered the star\u2019s chemistry, making it an anomaly in the study of stellar evolution.<\/p>\n
Rapid Rotation: A Clue to the Star\u2019s Violent Past<\/p>\n
The red giant\u2019s rapid rotation is another key feature that hints at a dramatic history. Scientists observed that the star rotates once every 398 Earth days, a much faster spin than most red giants of a similar age. This rapid rotation is not characteristic of stars in isolation. According to Joel Ong, a NASA Hubble Fellow and team member on the project, <\/p>\n
\u201cIf this rotation is real, it can\u2019t be explained by the star\u2019s birth spin alone. The star must have been spun up through tidal interactions with its companion, which further supports the idea that this system has a complex history.\u201d<\/p>\n
Such fast spinning can occur when a star undergoes tidal interactions with a close companion, such as a black hole, which exerts gravitational forces that accelerate the star\u2019s rotation. This interaction also likely plays a role in the observed starquakes, a phenomenon that occurs when the star\u2019s internal structure is disturbed by its companion. The faster a star spins, the more pronounced the effects of these tidal forces. This further supports the theory that Gaia BH2\u2019s red giant star was influenced by its proximity to the black hole, or even interacted with another star in the system\u2019s past.<\/p>\n
The Mysterious Birth of the Black Hole: The Role of the Black Hole Companion<\/p>\n
The presence of a black hole in the Gaia BH2 system adds another layer of complexity to the story. Black holes are notoriously difficult to study directly, but their gravitational influence on nearby stars can offer valuable clues about their formation and history. The discovery of Gaia BH2\u2019s black hole, along with its red giant companion, has provided new insights into the role of black holes in stellar evolution.<\/p>\n
The black hole likely formed when a massive star in the binary system collapsed at the end of its life, creating the gravitational well that the red giant star now orbits. The transfer of mass between the black hole and the red giant may have occurred at the time of the black hole\u2019s formation, leading to the star\u2019s current unusual properties. As Hey explains, <\/p>\n
\u201cThe combination of youth and ancient chemistry suggests this star didn\u2019t evolve in isolation. It likely acquired extra mass from a companion, either through a merger or by absorbing material when the black hole formed.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"In a groundbreaking discovery, scientists using NASA\u2019s Transiting Exoplanet Survey Satellite (TESS) have uncovered a celestial \u201csong\u201d emanating…\n","protected":false},"author":2,"featured_media":165529,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[111,139,69,147,392],"class_list":["post-165528","post","type-post","status-publish","format-standard","has-post-thumbnail","category-space","tag-new-zealand","tag-newzealand","tag-nz","tag-science","tag-space"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/165528","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=165528"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/165528\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/165529"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=165528"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=165528"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=165528"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}