A massive star with a mass of approximately 25 solar masses will eventually become a red supergiant.
Describe and explain the next stages of evolution of this massive star.
Vega is a bright star in the constellation Lyra. The table below shows some data about Vega and about our Sun.
| Vega | Sun | |
|---|---|---|
| Surface temperature / K | 5.8×1035.8 \times 10^35.8×103 | |
| Luminosity / W | 1.54×10281.54 \times 10^{28}1.54×1028 | 3.85×10263.85 \times 10^{26}3.85×1026 |
| Wavelength of emitted light at peak intensity / nm | 302302302 | 500500500 |
Show that the surface temperature of Vega is approximately 9600 K9600\text{ K}9600 K.
Calculate the radius of Vega.
A science fiction writer describes a stable stellar remnant consisting of a white dwarf with a mass of 1.651.651.65 solar masses.
Explain why this scenario is astrophysically impossible.
