Stellar Astronomy - Measuring surface temp of the Sun

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SUMMARY

The discussion focuses on calculating the surface temperature of the Sun using its angular diameter and the solar constant. The key equation utilized is L=4π(R^2)σT^4, where L represents luminosity, R is the distance from the Sun, σ is the Stefan-Boltzmann constant, and T is the temperature. A critical point made is that the solar constant observed on Earth is only a fraction of the total energy emitted by the Sun, necessitating the multiplication of the solar constant by the surface area of a sphere with the Sun at its center to derive luminosity. Finally, Planck's equation is suggested for determining the temperature from luminosity.

PREREQUISITES
  • Understanding of the Stefan-Boltzmann Law
  • Familiarity with Planck's Law
  • Knowledge of angular diameter measurements
  • Basic concepts of luminosity and solar constants
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  • Study the Stefan-Boltzmann Law in detail
  • Learn about Planck's Law and its applications in astrophysics
  • Research methods for measuring angular diameter in astronomy
  • Explore the concept of solar constants and their implications in solar physics
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Astronomy students, astrophysicists, and educators looking to deepen their understanding of solar measurements and temperature calculations.

PsychoDash
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Homework Statement



"Determine a surface temperature value for the Sun from the angular diameter of the Sun and the solar constant."

Homework Equations



L=4π(R^2)σT^4

The Attempt at a Solution



At this point my only stumbling block is I don't understand the relationship between the solar constant and luminosity.

edit: Is it as simple as multiplying by the square of the distance?
 
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The units of the different sizes tells a lot, actually.

Keep in mind that the solar constant on Earth is just a wee bit of the total energy radiating from the sun, that is the luminocity. Picture a large sphere with the distance between the sun and Earth as a radius; the solar constant applies to to everywhere in this sphere, so you must actually multiply with the area og this sphere to get the luminocity. Then you can use Placks equation to get the temperature.
 

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