Calculating luminosity given accretion power

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SUMMARY

The discussion focuses on calculating luminosity from accretion power, specifically using the equation Luminosity = η x (Δm/Δt) x c². The accretion power is given as Δm/Δt = 1.5 solar masses/year. To obtain luminosity in Joules per second (J/s), it is essential to convert the accretion rate from solar masses per year to kilograms per second. This conversion is necessary to ensure all units are consistent and yield the correct SI unit for luminosity.

PREREQUISITES
  • Understanding of accretion power and its units
  • Familiarity with the equation for luminosity
  • Knowledge of unit conversion between solar masses and kilograms
  • Basic grasp of the speed of light (c) in meters per second
NEXT STEPS
  • Learn about unit conversions between solar masses and kilograms
  • Study the principles of luminosity in astrophysics
  • Explore the efficiency factor (η) in energy calculations
  • Investigate the implications of accretion power in astrophysical contexts
USEFUL FOR

Astrophysics students, researchers in stellar dynamics, and anyone involved in calculations related to luminosity and accretion processes.

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Homework Statement



I have a question regarding calculating luminosity given accretion power. I have accretion power given to me as Δm/Δt= 1.5 solar masses/yr, in order to solve for luminosity are we supposed to convert the accretion power into solar masses/seconds or is it just some kind of variable where it doesn't matter. [I have to find the luminosity in Joules/sec]

Homework Equations



Luminosity= η x (Δm/Δt) x c^2


The Attempt at a Solution



My answer would be that I do have to convert because one joule= kg x m^2/ s^2 and if I have to find the Joules/sec I cannot leave the years unconverted.

(sorry if it was a dumb question, I think I answered it myself just working through explaining it to you guys)
 
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Yes, to get an answer in SI units you have to convert the accretion rate into kg/s through the conversions between solar masses to kilograms, and years to seconds. Then, you can use c in m/s and the efficiency will be a dimensionless number, so you can just multiply through and your answer will be in J/s, as you observed.
 

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