Tag

Gaia

All articles tagged with #gaia

science1 day ago•11 min saved

First Rogue Planet Mass Measured Confirms Galactic Population of Free-Floaters

Astronomers using a microlensing event observed from Earth and Gaia have measured both the mass and distance of a rogue planet about 9,800 light-years away, finding it Saturn-mass and confirming that the Milky Way hosts billions to possibly trillions of such starless worlds; the result leverages mass-distance measurements previously difficult for rogue planets and points to future surveys by the Roman Space Telescope to uncover many more.

via Space Daily|

#exoplanets #gaia #microlensing

space19 days ago•8 min saved

Could Dark Matter Be the Real Heart of the Milky Way?

Astronomers are rethinking the Milky Way’s centre: the long-held view that a supermassive black hole (Sagittarius A*) sits at the heart may be challenged by a fermionic dark matter core that could explain the observed stellar motions and even mimic the black hole’s shadow. Distinguishing the scenarios hinges on precise orbital precession measurements, which future upgrades like GRAVITY+ and the Extremely Large Telescope (and next-gen EHT observations) could enable. If verified, the idea would reshape galactic dynamics and dark matter physics, forcing a rethink of how galaxies host and regulate their centres.

via BBC Sky at Night Magazine|

#black-hole #dark-matter #gaia

science1 month ago•13 min saved

Exoplanet Archive Sees 6,000 Confirmed Worlds, Aims for 100,000 Soon

NASA’s Exoplanet Archive has surpassed 6,000 confirmed exoplanets, a milestone announced by JPL and maintained by Caltech’s IPAC; the figure is a lower bound on total planets and reflects detection biases toward certain methods. Growth has been uneven, driven largely by transit surveys from Kepler and TESS, but the next leap could reach ~100,000 planets within six to seven years thanks to Gaia’s upcoming astrometry data release and the Roman Space Telescope’s microlensing survey, starting around 2026–2027. The archive is being redesigned to ingest and link tens of thousands of candidates yearly, making the 100,000 figure a checkpoint for population statistics and atmospheric studies rather than a simple headcount of worlds.

via Space Daily|

#astronomy #exoplanets #gaia

science1 month ago•18 min saved

Astronomers Trace Loki, a Dwarf Galaxy Consumed by the Milky Way, in Its Disk

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.

via KSL.com|

#dwarf-galaxy #gaia #loki

space1 month ago•63 min saved

Bones of Loki Reveal Ancient Milky Way Merger in Its Disk

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.

via Live Science|

#dwarf-galaxy #gaia #loki

space2 months ago•10 min saved

Milky Way Edge Mapped: Star Formation Ends 40,000 Light-Years Out

Astronomers mapped a clear boundary to the Milky Way’s star-forming disk at about 40,000 light-years from the center by analyzing stellar ages and using galaxy simulations; inside this radius star formation continues, while beyond it older stars migrated outward, creating a distinctive U-shaped age pattern.

via SciTechDaily|

#gaia #milky-way #radial-migration

science2 months ago•38 min saved

Milky Way's star-forming disk ends at 40,000 light-years from the center, baffling astronomers

Astronomers mapped the Milky Way’s star-forming disk and find that active star formation ends at roughly 40,000 light-years from the center; the Sun sits well inside this boundary at about 26,000 ly. The stellar age distribution forms a U shape—young toward the center and older beyond the edge due to radial migration where stars born closer in travel outward along spiral arms. Simulations suggest a sharp drop in star-formation efficiency at 40,000 ly, potentially linked to the Galaxy’s bar or disk warp. The finding relies on Gaia data plus ground-based spectroscopy from LAMOST and APOGEE and is published in Astronomy & Astrophysics.

via Yahoo|

#gaia #galactic-disk #milky-way

space2 months ago•73 min saved

Milky Way's star-forming disk ends 40,000 light-years from the center, baffling astronomers

Astronomers mapped ages for about 100,000 bright stars across the Milky Way’s disk and found that active star formation effectively ends at roughly 40,000 light-years from the Galactic center, creating a U-shaped age profile where younger stars lie inward and older ones outward. The outer stars likely reach those distances via radial migration along spiral waves rather than in situ formation. The boundary’s origin could relate to the Milky Way’s bar or disk warp, with Gaia data combined with ground-based spectroscopy (LAMOST and APOGEE) and simulations helping explain the phenomenon, though the exact mechanism remains under study.

via Space|

#gaia #galactic-disk #milky-way

science2 months ago•25 min saved

Seven Sisters Myth May Date to 100,000 Years Ago

Using Gaia data, researchers argue the Pleiades would have looked like seven distinct stars 100,000 years ago, offering a plausible origin for cross-cultural 'Seven Sisters' myths and suggesting oral traditions could preserve a single star-based story for up to about 4,000 generations, though the claim is inferential and not proven.

via ZME Science|

#gaia #mythology #oral-tradition

astronomy2 months ago•9 min saved

Undergrad Team Finds Pristine Ancient Star Migrating from the Large Magellanic Cloud

A University of Chicago undergraduate team using Sloan Digital Sky Survey data identified SDSSJ0715-7334 as an ultra-pristine, extremely metal-poor star (0.005% of the Sun’s metals) that likely formed in the Large Magellanic Cloud before migrating into the Milky Way; Gaia data confirms its past orbit and its carbon is undetectable, offering a rare glimpse into the conditions of the early universe.

via SciTechDaily|

#ancient-immigrant #astronomy #gaia

science3 months ago•8 min saved

Astronomers map 45 rocky exoplanets as prime targets in the search for habitable worlds

Researchers using Gaia data and the NASA Exoplanet Archive identify 45 rocky exoplanets in the habitable zone (plus 24 near-edge worlds) that could sustain Earth-like conditions, spotlighting planets such as Proxima Centauri b and TRAPPIST-1 d–g. The list should guide observations with JWST, the Roman Space Telescope, ELT, LIFE and other missions to study atmospheres, test habitability limits, and refine the definition of the habitable zone.

via The Royal Astronomical Society|

#earth-like #exoplanets #gaia

science3 months ago•4 min saved

Sun's Galactic Journey May Have Made Life on Earth Possible

Astronomers using Gaia data found Sun-like stars, including the Sun, clustered around 4–6 billion years old at similar distances from the Galactic center, implying the Sun migrated outward from the core; this migration helps time the Milky Way's corotation barrier and suggests moving away from the center aided life’s emergence on Earth.

via BBC Sky at Night Magazine|

#gaia #galaxy #life

space3 months ago•2 min saved

Sun’s Galactic Escape Tracked by Gaia’s Twin Stars

A Gaia-based study of ~2 billion stars found 6,594 solar twins clustered in the 4–6 billion-year range near the Sun’s current orbit, suggesting a mass outward migration from the galactic core during the Milky Way’s bar formation. The temporary lowering of a corotation barrier likely allowed Sun-like stars to drift outward, placing our Sun in a calmer region conducive to life.

via Universe Today|

#gaia #galactic-bar #milky-way

space3 months ago•2 min saved

Sun's Galactic Escape: From Core to a Life-Friendly Orbit

Researchers using Gaia data analyzed nearly two million stars and found 6,594 Sun-like stars around 4–6 billion years old, suggesting the Sun migrated from the Milky Way's inner regions to its current calmer orbit about 26,000–28,000 light-years from the center; the move likely occurred as the galaxy's central bar formed and accelerated stellar birth, moving many stars outward, which would have given Earth a more benign environment for life to emerge and evolve; studying solar twins helps reconstruct the solar system's early history.

via Gizmodo|

#gaia #galactic-migration #milky-way

astronomy3 months ago•13 min saved

Sun's Galactic Escape Traced Through Solar Twin Migrants

Using Gaia data, scientists found that the Sun and thousands of Sun-like stars formed near the Milky Way's center about 4–6 billion years ago and migrated outward in a synchronized wave, likely aided by the galaxy's central bar, reshaping our understanding of the Sun’s origin and the Milky Way's history.

via ZME Science|

#astronomy #gaia #galactic-archaeology