⚙️ how
How do astronomers determine what a star is made of?
SpaceStars
Quick Answer
They split the light into a spectrum and identify absorption lines from different elements. Each chemical element leaves a unique fingerprint.
The Full Story
When a star’s light passes through its cooler outer layers, atoms and ions absorb specific wavelengths, creating dark lines in the spectrum. By comparing those lines with laboratory spectra, astronomers can identify elements such as hydrogen, helium, calcium, iron, and sodium. The technique was developed in the 19th century and transformed astronomy into a physical science. It also revealed that stars are mostly hydrogen and helium, unlike Earth’s rock-rich composition.
Key Facts
1.Stars are mostly hydrogen and helium
2.Spectroscopy became central to astronomy in the 1800s
3.Each element has a unique spectral fingerprint
YouTube Angle
Suggested video title for this topic:
"How light tells us what a star is made of"