All articles tagged with #dwarf galaxy
Astronomers have found 20 metal-poor stars near the Milky Way's disk that likely originated in a now-destroyed dwarf galaxy called Loki; the stars' shared chemistry and orbits suggest Loki was absorbed about 10 billion years ago, offering new clues about the Milky Way's early growth through data from Gaia and follow-up observations.
Astronomers identified 20 old, very metal-poor stars orbiting close to the Milky Way’s disk whose chemistry and motions suggest they originated in a dwarf galaxy nicknamed Loki that merged with the Milky Way more than 10 billion years ago. The inferred Loki had about 1.4 billion solar masses, and the study shows how ancient mergers can leave detectable stellar signatures in the inner Galaxy; further observations are needed to confirm Loki and map similar remnants.
Scientists contend that an ancient dwarf galaxy, dubbed Loki, is embedded in the Milky Way and was absorbed billions of years ago. By studying 20 metal-poor stars in the galactic plane, they found chemical traces of past supernovae and neutron star mergers but no white-dwarf signatures, implying Loki formed quickly and contributed stars with mixed orbital directions—evidence of an early accretion event. The findings appear in Monthly Notices of the Royal Astronomical Society.
Scientists discovered an unexpectedly large black hole at the center of the tiny galaxy Segue 1, challenging previous beliefs that such small galaxies are primarily held together by dark matter. The black hole, about 450,000 times the mass of the sun, is more massive than all the galaxy's stars combined, prompting a reevaluation of galaxy formation and evolution theories.
Researchers have discovered a supermassive black hole at the center of the nearby dwarf galaxy Segue 1, challenging previous assumptions that dark matter was the main binding force in such galaxies, and suggesting a need to revise models of galaxy evolution.
Astronomers have discovered a wandering intermediate-mass black hole actively accreting matter and producing jets in a dwarf galaxy, challenging the traditional view that black holes are only found at galactic centers and shedding light on black hole growth and galaxy evolution.
Astronomers have discovered supernova 2023ufx, the most metal-poor stellar explosion observed, in a dwarf galaxy. This finding provides insights into the early universe's conditions, aiding in understanding galaxy formation and evolution. The supernova's unique properties, such as its rapid brightness decline and fast-moving ejected material, suggest that rapidly spinning metal-poor stars were common in the early universe. The discovery, facilitated by advanced instruments like the James Webb Space Telescope, offers a benchmark for future studies on metal-poor stars and cosmic evolution.
Astronomers have discovered a faint and tiny collection of stars, Ursa Major III / UNIONS 1 (UMa3/U1), orbiting the Milky Way, possibly dominated by dark matter and challenging our understanding of galaxy formation. The system, located 30,000 light-years away, consists of around 60 10-billion-year-old stars and may be either a dwarf galaxy or a star cluster. The stars are gravitationally bound together, and the team's analysis suggests that dark matter is responsible for holding them in their group. This discovery may have implications for the Lambda Cold Dark Matter (LCDM) model and could potentially redefine the concept of a 'galaxy.'
Astronomers have discovered a peculiar system of stars, Ursa Major III/Unions 1 (UMa3/U1), 30,000 light-years away, containing only 60 visible stars and possibly dominated by dark matter. Its nature is uncertain, with two possibilities: a tiny galaxy stabilized by dark matter or a star cluster observed at a unique time. If UMa3/U1 is a dwarf galaxy, it could provide insights into how the Milky Way formed and challenge current understanding of galaxy formation. The system's low luminosity has made it difficult to detect, and its discovery may lead to a new class of extremely faint stellar systems.
Astronomers have discovered UMa3/U1, the faintest star system ever observed orbiting the Milky Way galaxy, located 30,000 light-years away in the constellation Ursa Major. The system, containing a mere 60 stars spanning about 10 light-years across, poses a mystery as to whether it is a true dwarf galaxy or a star cluster, with the role of dark matter being a key factor. This discovery challenges our understanding of galaxy formation and offers the potential to revolutionize our understanding of the universe's structure.
Astronomers have used the James Webb Space Telescope to study the stellar populations of the extremely metal-poor blue compact dwarf galaxy I Zwicky 18. Their observations revealed extreme populations of bright, recently formed massive stars, as well as candidate populations of dusty evolved stars and young stellar objects. The study provides important insights into the demographics of younger and older stellar populations in this galaxy, making it an ideal laboratory to study star demographics in an environment similar to that found shortly after the Big Bang.
NASA's Hubble Space Telescope has captured a distant dwarf galaxy in the Virgo cluster, located 52 million light-years away from Earth, revealing cosmic wonders and sparking awe among viewers worldwide. The image, shared on Instagram, highlights the galaxy's location and the challenges it faces within the Virgo cluster, shedding light on the impact of cosmic forces such as ram pressure. The post has garnered immense attention, with enthralled netizens expressing profound fascination with the mysteries of the universe unveiled by the Hubble Space Telescope.
The discovery of the isolated dwarf galaxy PEARLSDG by the James Webb Space Telescope challenges existing theories of galaxy evolution by not forming new stars, prompting a reevaluation of our understanding of galaxies. This unexpected finding suggests that many more isolated quiescent galaxies may exist, and the advanced capabilities of the JWST have the potential to uncover further cosmic phenomena, revolutionizing our understanding of galaxy formation and evolution.
Astronomers have discovered a faint, isolated dwarf galaxy named PEARLSDG, located 98 million light-years away with no known neighbors, challenging current understanding of galaxy evolution. This inactive dwarf galaxy, found in the background of an image taken by Nasa's James Webb Space Telescope, contradicts previous observations of isolated dwarf galaxies, which typically show star-formation activity. The discovery, published in The Astrophysical Journal Letters, provides new insights into galaxy formation and challenges existing theories.
The James Webb Space Telescope (JWST) captured an image of a distant, isolated dwarf galaxy named PEARLSDG, which is unusual for its lack of star formation and absence of close neighbors. The galaxy's distance of about 98 million light-years was measured by observing individual red giant branch (RGB) stars, indicating an older stellar population that ceased forming stars at least one billion years ago. Despite having no visible signs of interactions with other galaxies, the discovery challenges current theories of galaxy evolution and suggests the potential for more isolated quiescent galaxies to be identified with the JWST.