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

Why are Cepheid variables important? O Cepheids variables are pulsating stars whose pulsation periods are directly related to their true luminosities. Therefore they can be used as distance indicators. O Cepheids variables are supermassive stars that are on the verge of becoming supernovae. Therefore they allow us to choose candidates to watch if we hope to observe a supernova. O Cepheid variables are stars that vary in brightness because they harbor a black hole. Therefore, they provide direct evidence for black holes. O Cepheids variables are a type of irregular galaxy, much more common in the early universe. Therefore they help to understand how galaxies formed.

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.]

Protostar A. among the most massive and brightest stars Main Sequence B. a star after it has used all of its nuclear fuel Giant C. a gravitational field so strong that not even light can escape upergiant D. star in the longest stage of life (90% of stars) Neutron Star E. a super bright explosion of a star Black Hole F. created when a star loses its outer layers of gases White Dwarf G. extremely dense remnants of a dead star Black Dwarf H. young star in the early stages of formation jupernova 1. star that no longer gives off heat or light Planetary Nebula J. star that is larger and brighter than a main sequence star : A : E : F

Describe each of the following in detail, indicating their respective origins and the differences between them: Nova, Supernova type 1, Supernova type II.

Which of the following statements about various stages of core nuclear burning (hydrogen, helium, carbon, etc.) in a high- mass star is not true? A. As each stage ends, the core shrinks and heats further. B. Each successive stage creates an element with a higher atomic number and atomic mass number. C. As each stage ends, the reactions that occurred in previous stages continue in shells around the core. D.Each successive stage lasts for approximately the same amount of time.

When the Sun becomes a red giant, it's luminosity will be 2000 times its current value. The solar flux at Earth will also increase by a factor of 2000. Neglecting the greenhouse effect, the surface temperature of the earth is determined by thermal equilibrium: the flux of radiation absorbed equals the flux of radiation emitted. This means the Earth's surface flux must also increase by a factor of 2000.  If the current average surface temperature is 58 degrees F, what will the average surface temperature be when the Sun is a red giant.  Express your answer in units of degrees Fahrenheit.  [Hint: Recall that the Stefan-Boltzmann law says that the flux F emitted by a blackbody is related to its surface temperature T (measured in Kelvins) is F=σT4  . Use this law in the form of a ratio, expressing T in Kelvins. Then convert back to Fahrenheit.]

What causes an aging giant star to produce a planetary nebula?

Why does a type II supernova explode? in two sentences.

A Type Ia Supernova is an example of a: