•Q1.
Sirius has an apparent magnitude of about -1.5 and an absolute magnitude of 1.4. Would you have to wait more than or
less than 30 years for
a radio signal to arrive from Sirius?
a. Less than 30 years.
b. More than 30 years.
•30 years matches light travel time for about 10
parsecs or 30 light years. If it were at 10 pc, then M would equal m. If farther away than 30 light years would need to have an absolute magnitude
greater than the apparent
magnitude, which it does.
•
• Question
2 (1 point) Hadar, at a distance of about 145 parsecs, has an absolute magnitude of -5.2. Which of the following is
most likely Hadar's apparent
magnitude?
a.-8.8 b.-3.9
c.0.6 d.85.9
•m – M = -5 +5 log d = -5 + 5log 145 = -5 +
5(2.16)
•m = -5.2 +5.8 =
0.6
•
• Question
3 In an H-R Diagram, stars with the largest radius are found in the ____ of the diagram. (Fill in the
blank.)
a.center
b.upper left corner c.
upper right corner d.lower
left corner