red giant or supergiant stars
very cool but very luminous, found in the upper right of the H-R diagram
main-sequence stars
the majority of stars in our galaxy, the sun for example, a very hot and luminous star
white dwarfs
very hot but very dim, not much larger in radius than earth
Before we can use parallax to measure the distance to a nearby star, we first need to know __________.
the earth sun distance
Which of the following is a valid way of demonstrating parallax for yourself?
Hold up your hand in front of your face, and alternately close your left and right eyes.
What is the cause of stellar parallax?
Earth's orbit around the Sun.
The more distant a star, the __________.
smaller its parallax angle
Approximately what is the parallax angle of a star that is 20 light-years away?
0.16 arcsecond
Suppose that a star had a parallax angle of exactly 1 arcsecond. Approximately how far away would it be, in light-years?
3.3 light-years
Rank them based on the time each takes, from longest to shortest, to go from a protostar to a main-sequence star during the formation process.
M6, G2, A5,O9
Rank the stars based on the strength of the radiation pressure that pushes outward as they are forming, from highest pressure to lowest pressure.
O9,A5,G2,M6
Rank the stellar mass ranges based on how many stars in each range you would expect to find in a young star cluster, from highest number to lowest number.
less than one solar mass, between 1 and 10 solar masses, between 10 and 30 solar masses, between 30 and 60 solar masses
Rank the stars based on their surface temperature from highest to lowest.
blue dwarf star, sun, an orange main-sequence star, a red supergiant star
protostar phase
radius much larger than the sun, luminosity much larger than the sun, pressure and gravity are not precisely balanced, energy generated by gravatational contraction
main-sequence star
energy generated by nuclear fusion, lasts about 20 billion years, surface radiates energy at the same rate th ecore generates energy
high mass stars
late in life fuse carbon into heavier elements, end life as a supernova, have a higher fusion rate during main sequence life
low mass stars
have longer life times, final corpse is a white dwarf, the sun is an example, end life as a planetary dwarf
The following figures show various stages during the life of a star with the same mass as the Sun. Rank the stages based on when they occur, from first to last.
contracting cloud of gas and dust, protostar, main sequence G star, red giant, planetary nebula, white dwarf
Provided following are various stages during the life of a high-mass star. Rank the stages based on when they occur, from first to last.
contracting cloud of gas and dust, protostar, main sequence G star, red giant, supernova, and neutron star
Provided following are various elements that can be produced during fusion in the core of a high mass main sequence star. Rank these elements based on when they are produced, from first to last.
helium, carbon, oxygen, iron
Match the Evolutionary Stage above to it's location on the Life Track (see diagram).
point 9
Proto-star - Energy supplied by gravitational contraction
Match the Evolutionary Stage above to it's location on the Life Track (see diagram
between points 1 and 3
Proto-star - Energy supplied by gravitational contraction
Match the Evolutionary Stage above to it's location on the Life Track (see diagram
between points 5 and 6
1st Red Giant - Contracting helium core and hydrogen shell burning
Match the Evolutionary Stage above to it's location on the Life Track (see diagram).
between points 3 and 5
Planetary Nebula - Outer envelope ejected
Match the Evolutionary Stage above to it's location on the Life Track (see diagram).
between points 7 and 8
Helium flash - Degenerate helium core ignites explosively
Match the Evolutionary Stage above to it's location on the Life Track (see diagram).
point 5
2nd Red Giant - Inert carbon core, double shell burning
Match the Evolutionary Stage above to it's location on the Life Track (see diagram).
between points 6 and 7
Main-Sequence - Hydrogen core burning
Match the Evolutionary Stage above to it's location on the Life Track (see diagram).
point 3