astronomy: stars

Have you ever wonder how many stars are there?

Did you ever try to count them all?

STARSMeasuring the stars, Giants,

Dwarfs and the Main Sequence

1.) ________ is born when an enormous cloud of hydrogen gas collapses until it is hot enough to burn nuclear fuel.

STAR

2.) The group of stars are called ________.

CLUSTERS

3.) It is the rate at which a star radiates energy into space.

Luminosity

4.) It is a graph that plots stars color and its luminosity.

Hertzsprung - Russell

Diagram 

5.) How many types are there to classify a star?

7

6.) ________ is an example of a yellow dwarf.

SUN

7.) The composition of stars is studied using _____________ in which their visible light is studied. 

SPECTROSCOPY

8.) These are the classification of stars; O, B, A, T, F, G, K, which letter does not belong to the group?

T

9.) Sirius and Vega are examples of a type A star. TRUE or FALSE

TRUE

10.) ___________ is the rate at which a star's radiated energy reaches an observer on Earth.

APPARENT BRIGHTNESS

11.) _____ stars  radiate most of their energy in the red and infrared region of the electromagnetic spectrum and thus appear red.

COOL

12.) Hot stars emit mostly _______ and ultra-violet rays.

BLUE

13.) It is the largest known type of star, some are almost as large as our entire solar system.

SUPERGIANT STARS

14.) A rapidly spinning neutron star that emits energy in pulses.

PULSAR

15.) The largest stars have the shortest life span. TRUE or FALSE

TRUE