======Colour and Temperature of Stars======


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====Summary====                   
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====Procedure====  
  - Connect a lamp in series with a variable resistor and a power supply.
  - Begin with a low current so that the lamp filament glows faint red or orange.
  - Slowly decrease the resistance to increase the current through the lamp.
  - Observe how the filament changes color as it gets hotter, moving from red to yellow to white.
  - Relate these changes to the way star colors correspond to stellar temperatures.




====Links==== 
Classroom Demonstrations: Colour and Temperature of Stars - Institute of Physics: 
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📄 Colour and Temperature of Stars - IOP: [[https://spark.iop.org/colour-and-temperature-stars]]\\


====Variations====
  * Use a school theatre or hall with dimmable lights to better observe color changes.
  * Compare the lamp with a discharge lamp that can produce blue-white light.
  * Photograph the lamp at different brightness levels and discuss “color temperature” in photography.




====Safety Precautions====
  * Ensure wires and connections are secure to prevent overheating.
  * Do not exceed the lamp’s rated voltage or current.
  * Keep liquids away from electrical apparatus.




====Questions to Consider====
  * Why do cooler stars appear red while hotter stars appear white or blue? (Cooler objects emit longer-wavelength light like red; hotter objects emit shorter-wavelength light, including blue.)
  * Why does the lamp not reach blue light in this demonstration? (The filament cannot reach the extremely high temperatures needed without burning out.)
  * How do photographers use the idea of color temperature? (They adjust for the color of different light sources to capture natural-looking images.)