Why is there an upper end in the main sequence of the H-R diagram?

What will be an ideal response?


The upper end in the main sequence of the H-R diagram shows that even if an extremely massive star does begin to form, stellar models reveal that such massive stars are unstable. To support the tremendous weight in such stars, the internal gas must be very hot, and that means it must emit floods of radiation that flow outward through the star. The resulting pressure of the radiation blows gas away from the star's surface in powerful stellar winds. The models indicate, for example, that a 60-solar- mass star sheds mass so rapidly that it can be reduced to less than 30 solar masses in only a million years.

Physics & Space Science

You might also like to view...

Capacitors in Combination: Three capacitors of equal capacitance are arranged as shown in the figure, with a voltage source across the combination. If the voltage drop across C1 is 10.0 V, what is the voltage drop across C3?

A. 20 V B. 10.0 V C. 40 V D. 30 V

Physics & Space Science

The refraction of light in a diamond is greater for

A) long-wavelength light. B) short-wavelength light. C) both refract the same

Physics & Space Science

A 600-kg car traveling at 30.0 m/s is going around a curve having a radius of 120 m that is banked at an angle of 25.0°. The coefficient of static friction between the car's tires and the road is 0.300

What is the magnitude of the force exerted by friction on the car? A) 1590 N B) 3430 N C) 7240 N D) 7820 N E) 795 N

Physics & Space Science

Two point charges of +1.0 ?C and -2.0 ?C are located 0.50 m apart. What is the minimum amount of work needed to move the charges apart to double the distance between them? (k = 1/4??0 = 8.99 × 109 N ? m2/C2)

A) +36 mJ B) +18 mJ C) -36 mJ D) 0 mJ E) -18 mJ

Physics & Space Science