Tag

Gaia

All articles tagged with #gaia

space1 month ago•11 min saved

Milky Way–Andromeda Collision Odds Fluctuate as New Data Refine Forecasts

New studies show the forecast of a Milky Way–Andromeda merger is far from settled: a 2025 Nature Astronomy analysis using Hubble and Gaia data suggested roughly 50–50 odds for a merger within the next 10 billion years, while a 2026 follow-up with Gaia-based motions pushed the probability toward about 90% under its preferred model; the results depend on uncertain motions and nearby galaxies (Triangulum and the Large Magellanic Cloud), and they distinguish between a first close approach and a final merger. Precise proper-motion measurements—down to microarcseconds per year—are needed to narrow the forecast.

via Space Daily|

#andromeda #gaia #galaxy-merger

science1 month ago•6 min saved

Gaia pins down a free-floating Saturn-mass world wandering the Milky Way

A Saturn-mass object (~0.22 Jupiter masses) measured via gravitational microlensing with Gaia parallax appears unbound to a star (or on a very wide orbit), about 3.05 kiloparsecs away. This supports population estimates that free-floating or very wide-orbit planets could outnumber stars by roughly 20 to 1, though uncertainties and model differences remain. The result is based on a single event, and future surveys like NASA's Roman Space Telescope will build a larger, clearer census, while ongoing work debates the mass-function shape at lower masses.

via Space Daily|

#free-floating-planets #gaia #microlensing

science-cosmology2 months ago•2 min saved

Ancient stars align with the older universe age, challenging younger estimates

A study analyzing about 250,000 old Milky Way stars using Gaia and LAMOST data finds the oldest stars to be about 13.73 billion years old, aligning with the 13.8‑billion‑year age inferred from the cosmic microwave background and weakening the case for the younger 12.5–12.9 billion-year age suggested by supernova measurements; the Hubble tension persists without this stellar-age result resolving it.

via Futura, le média qui explore le monde|

#age-of-the-universe #gaia #hubble-tension

astronomy2 months ago•132 min saved

Milky Way’s ancient 90-degree flip reshaped its halo

New Gaia measurements and computer simulations show the Milky Way’s halo rotates more slowly than its disk, likely because the galaxy underwent ancient head-on mergers and a dramatic disk flip that reoriented the disk by about 90 degrees. This misalignment slows halo rotation and could have shifted the solar system’s orbit, though the exact mechanism remains under investigation.

via Space|

#astronomy #disk-flip #gaia

technology2 months ago•7 min saved

Samsung backs NVIDIA with next-gen V-NAND as AI, foldables, and OLED strides unfold

Samsung is expanding its V-NAND production for NVIDIA’s CMX platform (V9, V10 and trials for V11) with ~100,000 wafers/month and a large share allocated to V9, signaling deeper AI memory collaboration; the company is also pursuing GAIA AI accelerators to boost Exynos and on-device AI. Separately, Galaxy Z Fold 8 teasers suggest a competitive push in foldables, and Samsung Display has begun shipping VESA DisplayHDR True Black 1400 OLED panels to premium laptops (e.g., Lenovo Yoga Pro 9i Aura Edition), underscoring a broad push across memory, AI hardware, foldables, and premium displays.

via Sammy Fans|

#foldables #gaia #nvidia

science3 months 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

space3 months 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

science4 months 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

science4 months 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

space4 months 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

space5 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

science5 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

space5 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

science5 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

astronomy5 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