Labs / Astronomy
Reading Starlight
A star's glowing surface makes a smooth rainbow, but the cooler gas above it stamps dark lines into that light — one exact pattern for each element. Toggle candidate elements to lay their reference lines over the spectrum, and see which fingerprints line up with the dark bands. That is literally how we know what stars, and everything else, are made of.
λ —line —match —
What to try
- Turn on Sodium. Its two lines sit almost on top of each other — can you zoom in far enough to split the pair apart?
- Switch to the Blue (B) star and crank the temperature up. Why do Helium's lines only show up on the hottest stars?
- On the Sun, slide the temperature toward 10,000 K. Which element's lines get stronger, and which fade out?
- Toggle on an element the star does not contain. How do its ticks tell you “no match”?
- If two different elements share a line at almost the same wavelength, how could you ever tell them apart?