Transcript Astrophotography -- Constellations and More

The Winter Skies
Jupiter
Venus
An (indoor) stargaze by Dan Roth
Orion
Orion Nebula
1500 ly away
12 million yrs old
Rigel
Canis Major
Sirius
Gemini
Castor
Pollux
Taurus and the Pleiades
400 ly away
100 million yrs old
Taurus
Aldebran
50 ly away
4 solar masses
40 solar radii
M45—The Pleiades
E
N
Atlas
Alcyone
Merope
Big Dipper
Alcor
Mizar
Not to scale
Mizar itself is in fact a double star,
and each of those components
are doubles. The 2 stars in Mizar
A orbit each other every 20 days
at half the distance from the sun
to Mercury.
Leo
Not to scale
Star Trails...
Canis major, 8 min exposure. The bright
trail on the left is Sirius
Orion, 4 min exposure. The
dotted line in the upper right is
probably an airplane, and the
long trail in the lower left is
probably a meteor.
...and some calculations
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S = 206265”/Fmm
S = 206265/50
S =4125.3”/mm
So, measuring the length of a trail on the
picture, one can calculate how far the star
moved across the sky
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For Sirius (8 min exp):
Trail length is 9mm
(4125.3”/mm)*(9mm) = 37127.7” or
about 10 degrees
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We can check ourselves by doing the
same for Orion, whose exposure was 4
minutes—half that of the Sirius picture.
We expect the distance to be half.
Trail length is about 5 mm (we're doing
well already!)
(4125.3”/mm)*(5mm) = 20626.5”
Multiply this by 2 and we get 4125.3” or
about 11 degrees.
This is a bit more than what we were
expecting, but it is only a 1% error, which
can be attributed to human errors such as
inexact measurements, inexact exposure
times and out-of-focus images.
Photo Technical Info.
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Jupiter and Venus
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Rite Aid Color Film (ASA 200), Pentax
Spotmatic, f/1.8, 5 sec exp, tripod w/55mm lens
Orion
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Kodak TX 400, Pentax K1000, f/2, 60 sec exp,
piggypack w/ 75-205mm zoom lens
Canis Major
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Kodak TX 400, Pentax K1000, f/2, 60 sec exp,
piggypack w/ 75-205mm zoom lens
Gemini
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Kodak TX 400, Pentax K1000, f/2, 20 sec exp,
tripod w/ 50mm lens
Taurus/Pleiades
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Kodak TX 400, Pentax K1000, f/2, 30 sec exp,
tripod w/ 50mm lens
Taurus
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Kodak TX 400, Pentax K1000, f/3.8, 5 sec exp,
tripod w/ 75-205mm zoom lens
The Pleiades
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Kodak TX 400, Pentax K1000, 120 sec exp,
prime focus
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The Big Dipper (handle)
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Kodak TX 400, Pentax K1000, f/2, 10 sec exp,
tripod w/ 50mm lens
The Big Dipper (bowl)
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Kodak TX 400, Pentax K1000, f/2, 20 sec exp,
tripod w/ 50mm lens
Leo (body)
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Kodak TX 400, Pentax K1000, f/2, 20 sec exp,
tripod w/ 75-205mm zoom lens
Leo (head)
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Kodak TX 400, Pentax K1000, f/2, 20 sec exp,
tripod w/ 75-205mm zoom lens
Orion Trails
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Kodak TX 400, Pentax K1000, f/4, 4 min exp,
tripod w/ 50mm lens
Sirius Trails
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Kodak TX 400, Pentax K1000, f//22, 8 min
exp, tripod w/ 50mm lens