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IB Physics SL B 1 15 Apparent Brightness Questions

Practise IB Physics SL B.1.15 by comparing apparent brightness and combined stellar light, using distance and intensity evidence to explain what observers see.

Syllabus
First assessment 2025
Course
Physics SL
Level
SL

Exam points

  • Explain apparent-brightness comparisons using received intensity, distance and the combined light of binary stars.
  • Distinguish a star's observed brightness from intrinsic luminosity when interpreting stellar descriptions.

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Study B.1.15—Apparent brightness conceptsOpen the corresponding Concept lesson for explanations, examples and exam connections.

IB Physics SL B 1 15 Apparent Brightness Questions question 1

[Maximum number: 1]

Alpha Centauri A and B form the closest binary star system to the Earth. This binary star system is the third brightest stellar object in the night sky.

Arcturus is the fourth brightest star in the night sky. Its apparent brightness is slightly greater than that of the star Alpha Centauri A.

Outline why the binary star system Alpha Centauri appears brighter than Arcturus.

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