Question

In: Physics

11b - Estimating Stars types How would you go about estimating the size of the star...

11b - Estimating Stars types

How would you go about estimating the size of the star called Betelgeuse using its absolute magnitude (-6) and its spectral class (M)? How many Sun's would it take to cross the diameter of Betelgeuse? The volume of Betelgeuse compared to the Sun. What about Rigel, a Blue Giant star? How does it compare to the Sun?

Solutions

Expert Solution

According to the question, the spectral type of the star Betelgeuse is M and its absolute magnitude is -6.

The spectral type M correspond to the surface temperature of 3000 K.

The relationship between absolute magnitude and luminosity is given by

where L_* is the luminosity of a zero magnitude star (Vega).

Here the luminosity of Vega is 40.12 .

Again we know that,

Where L is luminosity, R is radius, T is absolute temperature.

Thus,

$=> \left ( R/{R_{\bigodot }} \right )^{2} = \left ( L/L_{\bigodot }\right ) \times \left ( T_{\bigodot } /T )^{4 }= 10077.688\times \left (5800/3000 \right )^{4} = 10077.688\times 13.971 = 140795.38$

Thus, it would take approximately 751 Suns to cross Betelgeuse's Diameter.

Since , the volume of Betelgeuse will be times of the sun.

In case of a blue giant star, the radius is 5-10 times that of the Sun and the surface temperature is around 10000 K.

The estimated radius and Surface temperature of Rigel is 75 and 2

genius_generous answered 1 year ago

Next > < Previous

Related Solutions

How would you go about estimating the cost of capital for a new, early stage or...

How would you go about estimating the cost of capital for a new, early stage or emerging growth company? What are the similarities and differences in doing so for a mature, established company?

Two stars are the same size. One star has a temperature of 50,000 K, the other...

Two stars are the same size. One star has a temperature of 50,000 K, the other has a temperature of 5,000K. Compared to the cooler star, how many times more luminous should the hotter star be? Which star will appear bluer?

Briefly describe how you would go about normalizing data

If you were to set-up an informational interview, how would you go about this? What would...

If you were to set-up an informational interview, how would you go about this? What would be your first step? Who would you contact and why? What questions would you ask?

How would you go about explaining the usefulness of CVP to your organization?

How would you go about developing a vaccine for Alzheimer’s disease? What would you target? What...

How would you go about developing a vaccine for Alzheimer’s disease? What would you target? What is the evidence for this target(s)? How would the immune system attack this target? What are the normal physiological functions of the target? What are the potential complications or side effects of such a vaccine?

How can you determine the age of a star cluster in which all stars formed at the same time?

How can you determine the age of a star cluster in which all stars formed at the same time? (hint: think about the main sequence of stars and which stars evolve how quickly) Does the expanding universe expand into something? Is there a center from which the universe expands?