Imagine the Universe!
Imagine Home  |   Ask an Astrophysicist  |  
Ask an Astrophysicist
Library of Past Questions

Physics of Stars

First time visitors: Please be sure to read our main page!

  • Check out the resource links. These are the sites we often point to in answering your questions.
  • Browse through the library of questions below.

Resources for this Topic

  1. The Life Cycles of Stars

  2. StarChild: Stars

  3. Imagine the Universe! Stars

  4. The Natures of the Stars (http://www.astro.uiuc.edu/~kaler/sow/star_intro.html)

Library of Past Questions and Answers

    Constellations and Stars

For questions on names and appearances of constellations, names of individual stars, unusual stars seen on the sky etc., please see our Night Sky page.
    How Stars Shine

  1. Can you give me analogy to explain stars to young kids?

  2. Why do stars shine? (Middle School Level)

  3. Why do stars shine? (High School Level)

  4. Are there green stars?

  5. How are the temperatures of stars related to their colors?

  6. Can a particular star change color?

  7. What are the optimal wavelengths to view stars of differing spectral type?

    The Locations and Motions of Stars

  1. How do astronomers find the distances to stars?

  2. What is the nearest star other than the Sun?

  3. How many known stars are there within 100 light years of Earth?

  4. How many solar-type stars are within 50 light years of the Sun?

  5. Are stars only found in galaxies or globular clusters?

  6. How far is the furthest star visible from Earth

  7. How long does it take for the light from stars to be visible here on Earth?

  8. What keeps stars from crashing into one another?

  9. Are stars fixed or stationary?

  10. What are the different methods to weigh a star?

  11. Are there other ways to measure the mass of bodies in space rather than by gravitational means?

    Our Sun as a Star

  1. How does the Sun compare to other stars, is it average?

  2. How long does it take a photon to leave the Sun?

  3. How do we know the core temperature of the Sun?

  4. When will the Sun become a red giant star?

    Giant Stars

  1. What is a red giant?

  2. Are there any clear pictures of red or blue giants?

  3. Are there stars larger than red giants? Are they candidates for black holes?

  4. How do red giant stars lose mass?

  5. What is a yellow giant?

  6. What is the largest known star and how big is it?

  7. Are there any stars larger than the Solar System in volume?

  8. What are R,N,C & S stars?

    White Dwarf Stars

  1. How long does it take a Red Giant star to become a White Dwarf?

  2. Can you recommend an Internet site with information about white dwarfs?

  3. What is the surface temperature of a white dwarf star?

  4. What is a black dwarf?

  5. Can you explain the concept of degenerate gas pressure?

  6. Can a white dwarf really have a diamond core?

    ...and Other Types of Stars

  1. What are the different types of stars?

  2. What are brown dwarfs?

  3. What kind of stars are the Cepheid variables?

  4. What are Wolf-Rayet stars?

  5. Were massive stars more common in the early Universe?

  6. Are there sunspots on non-solar type stars?

  7. Why do some Red Dwarf stars have such huge flares?

    The Life Cycles of Stars

  1. How are stars formed, and how do they end up?

  2. Inside a nebula, how big are the immense balls of dust and gas before they become stars?

  3. How can astronomers determine the age of a particular star?

  4. How long do stars live?

  5. What are the life cycles of the stars?

  6. What is the chemical composition of stars?

  7. What fraction of hydrogen in the universe has ever been in the stars

  8. Is hydrogen necessary to form a star?

  9. Does the chemical composition of a star have an effect on its luminosity and life span?

  10. What part do neutrinos play in the life cycles of stars?

  11. What is the cause of the Helium Flash in evolved stars?

  12. Why don't large mass stars become degenerate like some low mass stars?

  13. Do neutrinos come from only supernovae, or from all stars?

    Clusters of Stars

  1. What is a star cluster?

  2. Is it possible to determine the age of a star cluster?

  3. Were the Pleiades formed in the Orion Nebula?

  4. If Globular Clusters rotate, why are they still round?

    Specific Stars

  1. Can you tell us what the closest star to the Sun, Alpha Centauri, is made of, what its measurements are, and if it has any special assets?

  2. I need some information about Deneb, Rigel, Betelgeuse, and Antares.

  3. Can you tell me about Polaris?

  4. What are the evolutionary changes happening to Polaris?

  5. Can you tell me about Vega?


Imagine the Universe is a service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Alan Smale (Director), within the Astrophysics Science Division (ASD) at NASA's Goddard Space Flight Center.

The Imagine Team
Acting Project Leader: Dr. Barbara Mattson
All material on this site has been created and updated between 1997-2012.

DVD Table of Contents
Educator's Index