The life-span of every star is related to mass, which determines luminosity (brightness). The table shows the masses, lifetimes, and luminosity of two stars compared to that of the Sun.

Question

How does the Sun's lifetime compare to other main sequence stars? Move each lifetime into the table next to the star it describes

Star: Proxima Centauri, Spica, Sun

Mass (Mo): 0.12, 11, 1

Main Sequence Lifetime (years) blank, blank, blank

Luminosity(LO): 0.0017, 2,200, 1

10⁷

10¹⁰

10¹²

Answer 1

To fill in the table with the main sequence lifetimes of the stars compared to the Sun, we need to understand the relationship between mass and main sequence lifetime:

• Lower mass stars (like Proxima Centauri) tend to have much longer lifetimes because they burn their fuel slowly.
• Higher mass stars (like Spica) have shorter lifetimes because they burn their fuel much more rapidly.

Based on typical values for main sequence stars:

• Proxima Centauri (0.12 Mo) will have an exceptionally long lifetime, around 10¹² years.
• Spica (11 Mo) will have a much shorter lifetime, around 10⁷ years due to its high mass.
• The Sun (1 Mo) has a main sequence lifetime of around 10¹⁰ years.

Now, we can fill in the table accordingly:

| Star | Mass (Mo) | Main Sequence Lifetime (years) | Luminosity (LO) | |---------------------|-----------|---------------------------------|------------------| | Proxima Centauri | 0.12 | 10¹² | 0.0017 | | Sun | 1 | 10¹⁰ | 1 | | Spica | 11 | 10⁷ | 2,200 |

So the completed table is:

• Proxima Centauri: Lifetime - 10¹² years
• Sun: Lifetime - 10¹⁰ years
• Spica: Lifetime - 10⁷ years