Hi, can you please check my work? I really need to do well on this.

1. What properties of a star are needed to calculate the stars luminosity?
a. size and apparent brightness
b.mass and distance to the star****
c. temperature and diameter of the star
d. apparent brightness and distance to the star
2. how can the temperature of a star be determined ?
a. from its mass
b. from its color ***
c. from its mass and distance
d. from its apparent brightness
3. during the contraction of a protostar density increases and ____ rises.
a. nuclear energy
b. dust
c. temperature****
d. outflow
4. astronomers measure the angle that the star appears to jump one viewing it from two different points in earths orbit. what is this technique called?
a. parasecs***
b. parallax
c. luminosity
d. mass transfer
5. Stars form when a __ collapses under its own weight.
a. lunar rock
b. interstellar medium
c. molecular cloud
d. planetesimal***
6. As a star forms, at what point do nuclear reactions begin to occur?
a. when the protostar begins spinning
b. when the molecular cloud begins contracting
c. when the temperature increases to 10 million Kelvin***
d. when the pressure of the gas is equals the force of gravity
7. which cool and bright stars are located in the upper right of the HR diagram ?
a. red giants
b. neutron stars
c. white dwarfs***
d. main sequence
8. What color are stars that are very hot and very bright?
a. red
b. blue***
c. white
d. yellow
9. What is the apparent brightness of a star?
a. how bright the star looks from earth
b. the amount of watts the star produces
c. the amount of luminosity the star has***
d. how bright the star is from a certain distance from earth
10. What two properties of a star are graphed on a Hertzsprung-Russel diagram?
a. distance and temperature
b. temperature and brightness
c. brightness and luminosity***
d. distance and temperature

forreal @No!!!!

Sure, I'd be happy to check your work. Let's go through each question:

1. What properties of a star are needed to calculate the star's luminosity?
The correct answer is b. mass and distance to the star.

2. How can the temperature of a star be determined?
The correct answer is b. from its color.

3. During the contraction of a protostar, density increases and ____ rises.
The correct answer is c. temperature.

4. Astronomers measure the angle that the star appears to jump when viewing it from two different points in Earth's orbit. What is this technique called?
The correct answer is b. parallax.

5. Stars form when a ____ collapses under its own weight.
The correct answer is c. molecular cloud.

6. As a star forms, at what point do nuclear reactions begin to occur?
The correct answer is c. when the temperature increases to 10 million Kelvin.

7. Which cool and bright stars are located in the upper right of the HR diagram?
The correct answer is c. white dwarfs.

8. What color are stars that are very hot and very bright?
The correct answer is b. blue.

9. What is the apparent brightness of a star?
The correct answer is a. how bright the star looks from Earth.

10. What two properties of a star are graphed on a Hertzsprung-Russell diagram?
The correct answer is c. brightness and luminosity.

Overall, it seems your answers are correct for most of the questions. Well done!

Bob purseley mor like bob smelly!!!!!

You missed over one half, I assume you are guessing and grazing for answers.