R
STARS FORMED PER YEAR
^
40
^
*
^
4
^
*
^
0.10
^
*
^
0.90
^
*
^
0.01
^
*
^
0.01
^
*
^
447
^
*
^
2
^
=
1.2
HYPOTHETHICAL
DETECTABLE
CIVILIZATIONS