Astronomy Review

Question 1

A fixed luminous point in the night sky that is a large, remote incandescent body like the sun.

Answer 1

Star

Question 2

A system of millions or billions of stars, together with gas and dust, held together by gravitational attraction.

Answer 2

Galaxy

Question 3

A cloud of gas and dust in outer space, visible in the night sky either as an indistinct bright patch or as a dark silhouette against other luminous matter. Out of the two categories of this, one is the birth place of all stars.

Answer 3

Nebula

Question 4

A scatter graph of stars showing the relationship between the stars’ absolute magnitudes or luminosities versus their spectral classifications or effective temperatures.

Answer 4

H-R Diagram

Question 5

The degree or intensity of heat present in a substance or object, especially as expressed according to a comparative scale and shown by a thermometer or perceived by touch.

Answer 5

Temperature

Question 6

The intrinsic brightness of a celestial object (as distinct from its apparent brightness diminished by distance).

Answer 6

Luminosity

Question 7

A series of star types to which most stars belong, represented on a Hertzsprung–Russell diagram as a continuous band extending from the upper left (hot, bright stars) to the lower right (cool, dim stars).

Answer 7

Main Sequence

Question 8

A star with substantially larger radius and luminosity than a main-sequence (or dwarf) star of the same surface temperature. They lie above the main sequence (luminosity class V in the Yerkes spectral classification) on the Hertzsprung–Russell diagram and correspond to luminosity classes II and III.

Answer 8

Giant Star

Question 9

A star that is larger, brighter, and more massive than a giant star, being thousands of times brighter than the Sun and having a relatively short lifespan—only about 10 to 50 million years as opposed to around 5 billion years for the Sun.

Answer 9

Supergiant Star

Question 10

A small very dense star that is typically the size of a planet. A white dwarf is formed when a low-mass star has exhausted all its central nuclear fuel and lost its outer layers as a planetary nebula.

Answer 10

White Dwarf

Question 11

A region of space having a gravitational field so intense that no matter or radiation can escape.

Answer 11

Black Hole

Question 12

The middle of a wave length.

Answer 12

Amplitude

Question 13

The maximum points on a wavelength.

Answer 13

Crest

Question 14

The minimum points on a wavelength.

Answer 14

Trough