Download How Far To The Stars? By Vanessa Soto

How Far To The Stars?
By Vanessa Soto
Giovanni Cassini


First astronomer to
observe stellar
parallax of Mars.
He sent Jean Richer
to French Guyana
while he stayed in
Paris. They both
made simultaneous
observations of Mars.
Parallax


Hold your finger a few
inches in front of your
face. Close your right eye
and observe what your
finger is in front of on the
distant background. Do
the same for your left
eye.
The apparent shift of your
finger against the
background is parallax.
Stellar Parallax

The small annual
shifts in a star’s
apparent position
which is caused by
the Earth’s motion
around the sun.
Parallax Formula



D is the distance from
the Earth to the object
in pc.
P is the parallax
angle.
PC is parsec, the
distance to an object
with a parallax angle
of 1 arc second.
Parsec to Light-years
There are 3.26 light-years in one parsec. The parallax
formula will give us the distance in parsecs so we have to
use the formula PCx3.26 to get the distance in light-years.
Distance to the Stars
Celestial Parallax
Bodies Angle
D=1/P
D=PC
Convert
Lightyears
Sirius
0.379
1/.379
D=2.64
2.64x3.26
8.60
Proxima 0.772
Centauri
1/.772
D=1.30
1.30x3.26
4.24
Vega
0.125
1/.125
D=8
8x3.26 26.08
Altair
0.2
1/.2
D=5
5x3.26 16.3
Moon
0.5
1/.5
D=2
2x3.26 6.52
The End