Do stars of all masses acquire most of their mass via gravitational collapse of a single dense core?

A supernova’s energy is often compared to the total energy output of the Sun over its lifetime. Using the Sun’s current luminosity, calculate the total solar energy output, assuming a 1010 year main-sequence lifetime. Using Einstein’s formula E=mc2 calculate the equivalent amount of mass, expressed in Earth masses. [Hint: The total energy output of the Sun over its lifetime is given by its current luminosity times the number of seconds in a year times its ten billion-year lifetime; ; mass of earth = 6×1024kg; c = 3×108m/s. Your answer should be 200-300 Earth masses.]

How often can a star go supernova? Group of answer choices   Many times, depending on the size of its companion star.   Twice, the first time when it runs out hydrogen, and the second time when it runs out of iron.   Once, early in its evolution.   Once, late in its evolution.   At various times, depending on the composition of the star.

What is the escape velocity (in km/s) from the surface of a 1.1 M neutron star? From a 3.0 M neutron star?

How many years? Thank you!

What are the main products of the fusion reactions that take place in low mass main sequence stars?

The evolutionary track of a medium mass star is shown below. Which cut-away core diagram correctly illustrates the source of fusion energy when the star is at the indicated position? (A) H>He (B) He>C (C) (D) H>He H>He He>C Не Temperature А. (А) В. (В) C. (C) D.(D) Luminosity -

The answer is not 0.04. I need help!