Luminosity
Pretty Colors
H-R Diagram
Binary Stars
Calculations
100

Of these two luminosity values, this is the brightest one:

    -26    or   -12

What is -26?

100

These stars are extremely hot but very dim.

What are white dwarfs?

100

The diagonal band that runs from the upper left to the lower right of a HR diagram and is referred to this.

What is the main sequence?

100

This is the term for when one star (or other object) passes in front of another star.

What is an eclipse?

100

This is what each of the letters stand for in the equation L=TR2.

What is...

L - Luminosity

T - Temperature

R - Radius

200

This star has a luminosity of one on the H-R Diagram.

What is the Sun?

200

This is the color of the a very, very close G2 type star.

What is yellow?

(The star referred to is our sun)

200

"Oh Be A Fine Guy/Gal Kiss Me," in other words OBAFGKM.

What is the spectral classification for stars?

200

This is the shape of a light curve formed by two equally bright and equally sized stars.

What is ‾\/‾‾‾\/‾ ?

200

This is the luminosity (in solar units) of a star that is 2 times hotter than our sun and 2 times the size.

What is 64 times brighter?

L=TR2   --> L=222

300

This is the brightness stars appear to be from Earth, as they are right now.

What is apparent magnitude?

300
These colored stars are generally younger.
What is blue stars?
300

This is what is measured on diagonal axis: from bottom-left to top-right.

What is radius?

300

This is the shape of a light curve formed by two equally bright but different sized stars.

What is ‾\__/‾‾‾\__/‾ ?

300

This is the luminosity (in solar units) of a star that is 4 times hotter than our sun and 1/4 the size.

What is 16 times brighter?

L=TR2   --> L=(4)(1/4)2

400

This is defined as the brightness a star would have if it were at a distance d = 10 pc. (32.6 ly) from Earth.

What is absolute magnitude?

400

This is color of low-mass, but long-lived stars.

What is red?

400
Super giants are found in this corner of the HR-Diagram.
What is the upper right corner?
400

This is the approximate percent of how many visible stars are in a multi-star relationship.

What is between 66 - 85%?

400

This is the Radius of a star (in solar units) that is twice the brightness of our sun and four times as hot.

What is 9% the size of the Sun? (.09)

L=TR2   --> (2)=(4)R2

500

This is the luminosity (in terms of solar units) of a main sequence star that is twice the mass of our sun.

What is 8 times more luminous?

L=M3

L=(2)3 = 8

500

This type of "star" is not hot enough to fuse hydrogen in its core.

What is a brown dwarf?

500

These two astronomers plotted Luminosity & Temperature against each other to from a graph that all stars can be placed on.

Who are Hertzsprung and Russel?

500

This is the size and brightness comparison of this light curve:

What is "Same size, Different brightness"?

500

This is the temperature (in solar units) of a star that is 3 times dimmer than the Sun but 2 times bigger.

What is 54% the temperature of the Sun? (.54)

L=TR2   --> (1/3)=T(2)2