Summary: ASTR 3730: Astrophysics 1 Problem Set #3
Due in class Friday 17th
1) The table below lists the apparent magnitude m, distance d (in pc), and
effective temperature Te for a small sample of stars.
(a) Use the relation between the apparent magnitude and the absolute magnitude
M to fill in the absolute magnitude column.
(b) Plot the stars on an HR diagram, where the x-axis is log(Te) and the y-axis is
the absolute magnitude M. Follow the usual convention in which Te decreases
toward the right of the plot, and luminous stars fall in the upper part of the
(c) Indicate in the table which stars are main-sequence stars (MS), giants (G), or
white dwarfs (WD).
Star m d / pc Te / K M classification
Altair .76 5.1 8100
h Cas A 3.45 5.9 6030
h Cas B 7.51 5.9 3480
t Ceti 3.50 3.6 5120
UV Ceti 12.95 2.7 2700
e Eridani 3.7 3.3 4600