Absolute magnitude and luminosity

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SUMMARY

Two stars with the same absolute bolometric magnitude do not necessarily have the same absolute visual magnitude. Bolometric magnitude accounts for radiation emitted across all wavelengths, while visual absolute magnitude focuses solely on the visible spectrum. Consequently, stars with high surface temperatures may emit most radiation in the ultraviolet, resulting in a larger bolometric magnitude compared to their visual magnitude. Conversely, cooler stars primarily emit in the infrared, leading to a smaller absolute visual magnitude.

PREREQUISITES
  • Understanding of absolute bolometric magnitude
  • Knowledge of absolute visual magnitude
  • Familiarity with stellar surface temperature concepts
  • Basic principles of stellar radiation across different wavelengths
NEXT STEPS
  • Research the relationship between stellar temperature and radiation emission
  • Study the definitions and calculations of bolometric and visual magnitudes
  • Explore the spectral classification of stars and its implications on magnitude
  • Learn about the tools used for measuring stellar luminosity and magnitude
USEFUL FOR

Astronomers, astrophysics students, and anyone interested in stellar properties and their implications on luminosity and magnitude.

Rohan1997
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Do two stars of the same absolute bolometric magnitude have the same absolute visual magnitude?

If this is true; does this mean that two stars with the same power output have the same have the same bolometric magnitude and therefore same visual magnitude?
 
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Rohan1997 said:
Do two stars of the same absolute bolometric magnitude have the same absolute visual magnitude?

If this is true; does this mean that two stars with the same power output have the same have the same bolometric magnitude and therefore same visual magnitude?

When you say bolometric, it's about the radiation emitted at all wavelengths. Visual absolute magnitude, it's about the radiation emitted in the visible part of the spectrum. So you could have stars so hot that they emit the most of their radiation in the UV; for them, the bolometric magnitude would be much bigger than the visual magnitude. In the same way, cool stars would produce most of their radiation in the infrared and again, they would be barely visible (small absolute visual magnitude). It all depends on the surface temperature of the star.
 
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virgil1612 said:
When you say bolometric, it's about the radiation emitted at all wavelengths. Visual absolute magnitude, it's about the radiation emitted in the visible part of the spectrum. So you could have stars so hot that they emit the most of their radiation in the UV; for them, the bolometric magnitude would be much bigger than the visual magnitude. In the same way, cool stars would produce most of their radiation in the infrared and again, they would be barely visible (small absolute visual magnitude). It all depends on the surface temperature of the star.

Thank you this has filled the gap in my knowledge :)
 

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