Why are new Stars blue/white and old stars red/orange?
I'm not an astronomer, or a practicing physicist, bit I'm pretty sure it has to do with the levels of the energy released by the fusion reactions between different atoms. When a star is young it is comprised mostly of hydrogen, and when hydrogen atoms are fused together in the giant reactor that …
The Short Answer
I'm not an astronomer, or a practicing physicist, bit I'm pretty sure it has to do with the levels of the energy released by the fusion reactions between different atoms. When a star is young it is comprised mostly of hydrogen, and when hydrogen atoms are fused together in the giant reactor that is a star some of the high energy particles come out as blue(ish) photons, which are higher energy than red(ish) photons. As the star ages and the hydrogen atoms are combined into helium atoms, into lithium and on and on until you end up with mostly silicon and iron inside the star. A fusion reaction between those heavier elements is much less energetic than the fusion of the hydrogen atoms, and as a result the photons emitted by that reaction have lower energy. There's A LOT more physics behind it, but that's the basic EIL5
Analysis
Key Concepts: Atoms, energy, star
This explanation focuses on atoms, energy, star and spans 150 words across 5 sentences. At 121% above the average Space & Astronomy explanation (68 words), this is one of the more thorough answers in this category, reflecting the complexity of the underlying question.
What This Answer Covers
The explanation opens with: “I'm not an astronomer, or a practicing physicist, bit I'm pretty sure it has to do with the levels of the energy release” It then elaborates by presenting a contrasting perspective, ultimately building toward a complete picture across 5 connected points.
How This Compares in Space & Astronomy
Ranked #26 of 500 Space & Astronomy questions by answer depth (top 6%). This places it in the comprehensive tier — the top quarter of most thoroughly answered questions. Questions at this depth typically involve multi-faceted topics requiring nuanced explanation.
Frequently Asked Questions
Is there a simple explanation for why new stars blue/white and old stars red/orange?
I'm not an astronomer, or a practicing physicist, bit I'm pretty sure it has to do with the levels of the energy released by the fusion reactions between different atoms. When a star is young it is comprised mostly of hydrogen, and when hydrogen…
How detailed is this explanation compared to similar Space & Astronomy questions?
This is one of the most thorough answer at 150 words, ranked #26 of 500 Space & Astronomy questions by depth. The key concepts covered are atoms, energy, star.
What approach does this answer take to explain new stars blue/white and old stars red/orange?
The explanation uses contrasting perspectives across 150 words. It is categorized under Space & Astronomy and addresses the question through 1 analytical lens.