Stories
Hubble Reveals Weak Stellar Winds in Early-Universe Stars, Challenging Assumptions
- •A new Hubble Space Telescope survey, TEMPOS, found that extremely metal-poor massive stars have much weaker stellar winds than previously expected.
- •The study examined 29 massive O-type stars across six nearby dwarf galaxies, all with metallicities below one-fifth that of the Sun.
- •Astronomers use metallicity to describe the abundance of elements heavier than hydrogen and helium, which were far less common in the early universe.
- •The data showed that for stars with metallicity below about 10% of the Sun's, wind speeds dropped much more sharply than anticipated.
- •This finding could help astronomers better understand how massive stars influenced galaxies in the early universe and inform models for JWST observations.
Key Questions Answered
The Treasury of Extremely Metal-Poor O Stars (TEMPOS) survey used NASA's Hubble Space Telescope to study 29 massive O-type stars across six nearby dwarf galaxies. The survey revealed that extremely metal-poor massive stars have much weaker stellar winds than expected, with wind speeds dropping sharply at metallicities below about 10% of the Sun's.
Astronomers use metallicity to describe the abundance of elements heavier than hydrogen and helium within stars and galaxies. Early galaxies contained far fewer of these heavy elements compared to modern galaxies like the Milky Way.
The research team is combining Hubble's ultraviolet data with visible-light observations from the Keck Observatory. This combined approach aims to determine the chemical abundances and mass-loss rates of the stars in greater detail to build better models for interpreting early universe galaxies.
