Cosmic epoch · Cosmology
Cosmic Dawn & the First Stars
Cosmology & UniverseActive Research
Definition
The era when the first stars and galaxies formed and began to light up the Universe.
Scientific overview
The first stars (Population III) formed from pristine hydrogen and helium, were likely very massive, and forged the first heavy elements. The James Webb Space Telescope is now observing galaxies from a few hundred million years after the Big Bang, revealing this era directly for the first time.
Open questions
- When and how did the very first stars form?
- Why do some early galaxies look more evolved than expected?
Rests on
Measured by
Knowledge connections
- Depends onThe Cosmic Dark Ages
- Depends onStructure Formation
- Part of modelThe Lambda-CDM Model
- Measured byJames Webb Space Telescope
- Required byReionization
- Preceded byThe Cosmic Dark Ages
- Followed byReionization
Sources & references
The primary and reference sources this topic draws on.
- NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.
- ESAEuropean Space Agency
European missions, observatories, and space science imagery.