Astro 7N exam 2 The Sun Questions and Answers

Astro 7N exam 2 The Sun Questions
and Answers
what is the sun mostly made of?

✓ ~~~gas



true or false the sun is stable due to balance of gravity and gas pressure in its hot

interior

✓ ~~~true



how hot is the sun?

✓ ~~~15 million degrees kelvin



what is the sun diameter?

✓ ~~~109Xearth



what is the sun mass?

✓ ~~~333,000xEarth



what is the sun luminosity equal to?

✓ ~~~4x10^24 100 Watt light bulbs



how much of all of the made of the solar system in in the sun?

✓ ~~~99.9%



how long has the sun been shining, and how much longer will it shine?

, ✓ ~~~4.5 billion
5.5 billion




are slightly-cooler regions on the Sun's surface due to magnetic activity

preventing hot material from rising in that region; have 11 year cycles

✓ ~~~sunspots



a long last source of energy in the stars

✓ ~~~nuclear fusion



what is nuclear fusion made of?

✓ ~~~4 protons combine to make helium 4 and release energy in gamma rays



a fusion process in which protons build together to form helium

✓ ~~~proton proton chain



the energy output from the [p chain comes from

✓ ~~~E=mc2



true or false the mass of a helium-4 nucleus is less than the mass of 4 protons

✓ ~~~true



at the center; high density and temperature; where nuclear reactions occur

and gamma rays are produced