Tag

Planet Formation

All articles tagged with #planet formation

science1 day 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

space3 days ago•3 min saved

Dense Mega-Earth GJ 523b Defies Conventional Planet Formation

Astronomers confirm GJ 523b, a rock-dominated mega-Earth about 23 Earth masses and 2.5 Earth radii in a 170-million-year-old system, orbiting its star every 17.75 days. Its extreme density and thin atmosphere challenge standard models that would normally push such a core to become a gas giant, prompting theories like atmospheric stripping from stellar heat or a head-on collision of rocky protoplanets. This discovery provides a rare glimpse into how ultra-dense worlds form and evolve.

via geekspin|

#exoplanet #gj-523b #mega-earth

space6 days ago•159 min saved

GJ 523b: A colossal rocky world defying formation expectations

Astronomers have identified GJ 523b, an unusually dense exoplanet about 2.5 times Earth’s radius and roughly 23–24 times Earth’s mass, making it a so‑called mega‑Earth with a predominantly rocky composition and little atmosphere. Its high density challenges standard planet‑formation models that predict gas envelopes once cores reach ~20 Earth masses; explanations include atmospheric loss or a giant‑impact origin. The planet orbits its star every 17.75 days in a relatively young system (~170 million years old), with the discovery arising from NASA’s TESS data and ground‑based WIYN follow‑up observations.

via Space|

#density #exoplanet #gj-523b

space25 days ago•9 min saved

Uranus Clouds Reveal a Rotten-Egg Clue About Its Formation

Astronomers using Gemini North spectroscopy detected trace hydrogen sulfide above Uranus’s cloud tops (about 0.4–0.8 parts per million), confirming a sulfur-bearing layer and showing Uranus is chemically distinct from the inner gas giants. The planet’s blue color comes from methane, not sulfur, and while the “rotten egg” smell is a real footnote, any visitor would be overwhelmed by the extreme cold and unbreathable atmosphere long before odor could be noticed. The finding helps constrain how Uranus formed and where its clouds originate.

via Space Daily|

#atmosphere #hydrogen-sulfide #methane

space1 month ago•13 min saved

Directly imaged planet orbits two suns closer than any prior circumbinary world

A young giant planet about 5.6 times Jupiter’s mass, HD 143811 AB b, was directly imaged in a binary star system roughly 446 light-years away. It orbits the two stars at about 63 AU with a 320-year period, six times closer to the stellar pair than any previously imaged circumbinary planet. The discovery, made through reanalysis of archival Gemini/GPI and Keck/NIRC2 data, challenges current ideas about planet formation and migration in dynamically complex circumbinary disks and provides a valuable three-body laboratory for refining models of how such worlds form and evolve.

via Space Daily|

#astronomy #binary-stars #direct-imaging

space1 month ago•11 min saved

Diamond-Rain World Around a Pulsar Challenges Planet-Formation Theory

Using the James Webb Space Telescope, astronomers identified PSR J2322-2650b, a Jupiter-mass world orbiting a pulsar. Its atmosphere is unusually rich in helium and carbon, with nitrogen and oxygen largely absent, and its clouds may condense soot into diamond, implying a “diamond rain.” The planet’s nearly pure carbon composition and puzzling formation history defy current models, challenging the line between planet and stellar remnant and prompting new theories about how such worlds form.

via Space Daily|

#carbon-atmosphere #diamond-rain #exoplanet

science2 months ago•12 min saved

Lemon-shaped exoplanet around a pulsar reveals carbon-rich atmosphere, baffling formation theories

NASA’s James Webb Space Telescope observed PSR J2322-2650b, a Jupiter-mass planet in a lemon-like orbit around a millisecond pulsar, with an atmosphere dominated by molecular carbon (C2 and C3) rather than water or methane. The extreme carbon-to-oxygen and carbon-to-nitrogen ratios, plus the planet’s shape and winds, challenge current formation theories. The finding is based on spectra from a single planet using one instrument, so while striking, it highlights a new puzzle rather than a confirmed explanation for how such worlds form.

via Space Daily|

#carbon-atmosphere #exoplanet #planet-formation

space2 months ago•96 min saved

Planets Could Form in Turbulent Edges of Active Galactic Nuclei

New simulations suggest the outer edges of gas-rich accretion disks around active supermassive black holes could resemble planet-forming disks, allowing dust to clump via streaming instability and form millions of Jupiter-mass planets tens of parsecs (a few tens of light-years) from the black hole; these planets would likely migrate outward, and gravitational lensing could help detect them, though observations are still in early stages.

via Space|

#accretion-disks #active-galactic-nuclei #exoplanets

space2 months ago•36 min saved

Astronomers Spot a Ring That Could Be a Cosmic Planet Factory

Astronomers have detected a prominent ring in the disk around a young star, seen as a likely site where planets form. The ring’s structure and gaps suggest ongoing planet-building activity within a protoplanetary disk, offering new clues about how planetary systems originate, though follow-up observations are needed to confirm active planet formation inside the ring.

via Yahoo|

#astronomy #exoplanets #planet-formation

space3 months ago•6 min saved

Hubble Reveals the Biggest Chaotic Planet-Forming Disk Yet

NASA's Hubble Space Telescope captured the sharpest visible-light images yet of a colossal, highly irregular protoplanetary disk around a young star about 1,000 light-years away, nicknamed Dracula’s Chivito. The disk spans roughly 400 billion miles (about 40 times the solar system’s diameter to the Kuiper Belt) and is filled with massive, uneven filaments and wisps, suggesting turbulent accretion or external influences. With a mass estimated at 10–30 Jupiter masses, it could form several giant planets, underscoring that planet formation can be far more chaotic and dynamic than traditional models suggest. Future observations may reveal whether the central star is single or binary and shed light on how such extreme environments shape emerging planetary systems.

via The Daily Galaxy|

#disk-asymmetry #draculas-chivito #hubble-space-telescope

science3 months ago•5 min saved

Massive star clusters escape birth clouds first, sparking early UV glow in galaxies

Webb and Hubble studied roughly 9,000 young star clusters in four nearby galaxies (M51, M83, NGC 4449, NGC 628) and found the most massive clusters clear their birth clouds and begin emitting ultraviolet light after about 5 million years, while less massive clusters emerge after 7–8 million years—offering new constraints on how stellar feedback drives galactic evolution and influences early planet formation.

via European Space Agency|

#galactic-evolution #planet-formation #science

space3 months ago•4 min saved

TESS Finds 27 Hidden Worlds by Timing Eclipses in Binary Stars

NASA’s TESS analyzed 1,590 eclipsing binaries and found 27 candidate exoplanets by timing the stars’ mutual eclipses, a method that can detect planets even when they don’t transit. The candidates range from ~12 Earth masses to ~10 Jupiter masses, with confirmation needing follow-up velocity measurements; the work expands planet searches in binary systems beyond the standard transit approach.

via NASA Science (.gov)|

#binary-stars #eclipsing-binaries #exoplanets

space3 months ago•71 min saved

Two suns, more worlds: binary stars may birth more planets than single stars

New simulations suggest planets may form more easily in the outer parts of circumbinary disks around binary stars, as inner zones near the stars are too chaotic. Beyond a “forbidden zone,” disks can become gravitationally unstable and fragment to form multiple planets—often gas giants—while some worlds may be ejected as rogue planets. The study implies binary-star systems could host many planets, making Tatooine-like worlds less rare, and points to ALMA, JWST, and future telescopes to observe such disks; over 50 circumbinary planets are already known.

via Space|

#binary-stars #exoplanets #planet-formation

astronomy4 months ago•4 min saved

Relativity Could Explain Why Circumbinary Planets Are So Rare

Astronomers expected hundreds of planets orbiting binary stars, but only 14 have been found. New work in The Astrophysical Journal Letters suggests Einstein’s general relativity drives precession of the stars’ orbits that resonates with a planet’s orbit, destabilizing it. In tight binaries, this leads to a large instability zone and an “80% survival gap” in which planets are likely ejected or swallowed by the stars. As a result, there’s a desert of circumbinary planets for systems with orbital periods under about seven days, and most observed planets sit just outside the unstable region—likely formed farther out and migrated inward to the stability edge.

via The Daily Galaxy|

#astronomy #binary-stars #circumbinary

space-and-spaceflight4 months ago•16 min saved

JWST Settles Planet-or-Star Question for 29 Cygni b

Using JWST's near-infrared imaging, researchers directly imaged 29 Cygni b and found it metal-rich with an orbit aligned to its star, consistent with formation in a protoplanetary disk via rapid accretion; at about 15 Jupiter masses it’s a planet, not a star.

via Gizmodo|

#29-cygni-b #exoplanets #planet-formation