Lab 8: Magnitudes, Spectral Type, & the H-R Diagram

Magnitude Scale:

Astronomers use a magnitude scale that is based on the ________.

The more negative a number on the magnitude scale, the ________ the star is.

Apparent Magnitude (mv):

How bright an object ________ to be at its actual distance.

3 factors that determine a stars apparent magnitude:

Absolute Magnitude (Mv):

How bright an object ________ is at a fixed distance of ________ parsecs.

By knowing a star's apparent magnitude and absolute magnitude, we can get its distance through the relationship known as the distance modulus:

Temperature:

Spectral Type:

O

B

A

F

G

K

M

B-V Color Index:
The smaller the number, the ________ the star.