Page 38 - Astronomy - October 2017 USA
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STAR N
DOME
How to use this map: This map portrays the
sky as seen near 35° north latitude. Located
inside the border are the cardinal directions
and their intermediate points. To find
stars, hold the map overhead and
orient it so one of the labels matches
the direction you’re facing. The
stars above the map’s horizon
now match what’s in the sky.
The all-sky map shows
how the sky looks at:
10 P.M. October 1
9 P.M. October 15
8 P.M. October 31
Planets are shown
at midmonth TAURUS
E _
STAR
MAGNITUDES
Sirius
0.0
3.0
1.0
4.0
2.0 5.0
STAR COLORS
A star’s color depends
on its surface temperature.
• The hottest stars shine blue
• Slightly cooler stars appear white
• Intermediate stars (like the Sun) glow yellow
• Lower-temperature stars appear orange
• The coolest stars glow red
• Fainter stars can’t excite our eyes’ color
receptors, so they appear white unless you
use optical aid to gather more light
38 ASTRONOMY • OCTOBER 2017
