Tag: Stellar, planetary, and galactic studies
High-mass companions can widen common-envelope outcomes in giant stars
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in AstrophysicsWhat the study found The study found that higher companion mass ratios can produce wider orbits after a common-envelope event, which is an episode where two stars share a single outer envelope. Even so, the widest separation predicted here was still only about 50 solar radii, smaller than the observed range. Why the authors say…
BAGLE adds binary lens and source models for microlensing
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in AstrophysicsWhat the study found The BAGLE Python software package now includes models for binary sources and binary lenses in gravitational microlensing. These models include Keplerian orbits, as well as simpler descriptions of orbital motion such as acceleration, linear, or stationary motion of the secondary companion. Why the authors say this matters The authors say these…
Cluster stellar mass growth is mostly established by redshift 0.8
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in AstronomyWhat the study found The study found that, in a sample of massive galaxy clusters, the characteristic stellar mass in the cluster stellar mass function evolves only slightly from redshift 0.8 to 0.55, and that most measurable growth happens between redshift 0.55 and 0.2. The authors also report evidence that the stellar mass fraction in…
Solar prominences formed self-consistently in 3D simulations
What the study found The study found that solar prominences can form self-consistently in fully three-dimensional simulations when the magnetic field is set with appropriate initial conditions. In the simulations, a prominence began with a random ejection of dense plasma seed material from the chromosphere, the Sun’s lower atmospheric layer, into the corona. Why the…
NUV-blue spirals show star-forming outer disks
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in AstronomyStudy reveals why optically red spiral galaxies show ultraviolet-blue colors: quenched centers with active outer disks sustained by fresh gas accretion or galaxy interactions.
VLBI and Gaia agree on many long-period variable star distances
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in AstronomyCompare VLBI and Gaia DR3 astrometric measurements of 43 long period variable stars, revealing complementary strengths for determining stellar distances and proper motions across different.
SDSS-V catalogs Milky Way halo stars with new parameter pipeline
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in AstronomySDSS-V all-sky spectroscopic survey produces validated stellar parameter catalog enabling discovery of distant halo substructures and chemically peculiar stars across the Milky Way.
DM Tau disk shows non-thermal line broadening
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in AstrophysicsBayesian analysis of molecular line observations confirms nonthermal broadening of 0.4 sound speeds in the DM Tau protoplanetary disk, providing evidence for turbulence.
Supermassive stars may match JWST little red dot spectra
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in AstrophysicsSupermassive star models reproduce spectral signatures of JWST little red dots, suggesting these compact sources may be progenitors of the first supermassive black holes.
RUBIES finds many massive quiescent galaxies at 2 < z < 5
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in AstrophysicsSpectroscopic observations confirm that massive quiescent galaxies were surprisingly common at redshifts 2-5, challenging galaxy formation simulations.
