Astrophysics - Simple question

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In summary, the astronomer is trying to derive an algebraic expression for the distance to Alpha Centauri B using independent measurements of its apparent and absolute magnitudes, as well as a measurement of the extinction towards the star. This can be done using the equation (m-Av)-M=5log(d)-5 and rearranging it to solve for d. The uncertainty associated with this distance can be estimated using Gaussian error propagation, which involves adding multiple sources in quadrature.
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Homework Statement


An astronomer has independent measurements of both the apparent and absolute magnitudes of Alpha Centauri B, and a measurement of the extinction towards the star. Derive an algebraic expression for the distance to the star and a second expression that shows how the uncertainty associated with this distance can be estimated.

Homework Equations


(m-Av)-M=5log(d)-5

The Attempt at a Solution


OK, so I know that the above is the equation which contains all of the parameters I need and I know I can rearrange this equation to give me d, but that isn't deriving it.

Do I have to do a lot more than this?

Also, if this is correct then I know that I will end up with an equation that looks like this:

d=101/5(m-M-Av+5)

And I know that uncertainties is simply adding in quadrature, but I get very confused here as I have many variables all as a power of another number and I don't know how to approach this.

I don't want answers, I just want guidance.

Many thanks
 
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  • #2
Gaussian error propagation. If y=f(x), then ##\Delta y = \left| \frac{\rm{d}f}{\rm{dx}} \right| \Delta x## if ##\Delta x## is small enough. Add multiple sources in quadrature, if necessary.
 

Related to Astrophysics - Simple question

1. What is astrophysics?

Astrophysics is a branch of astronomy that deals with the physical properties and behavior of celestial objects and phenomena, such as stars, galaxies, and the universe as a whole.

2. How is astrophysics different from astronomy?

Astrophysics is a more specific and specialized field within astronomy that focuses on the physical and mathematical aspects of studying celestial objects, while astronomy is a broader field that encompasses the observation and study of all objects and phenomena in the universe.

3. What are some common topics studied in astrophysics?

Some common topics studied in astrophysics include the composition and structure of stars and galaxies, the evolution of the universe, the properties of dark matter and dark energy, and the origins of the universe and its various structures.

4. What are some practical applications of astrophysics?

Astrophysics has several practical applications, such as helping us understand and predict the behavior of celestial objects, improving our knowledge of space travel and navigation, and providing insights into the basic laws of physics and the origins of the universe.

5. What skills are necessary for a career in astrophysics?

A career in astrophysics typically requires strong mathematical and analytical skills, as well as a solid understanding of physics and astronomy. Strong problem-solving and critical thinking abilities are also important, along with the ability to work well with data and technology.

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