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The Winter Skies. An (indoor) stargaze by Dan Roth. Jupiter. Venus. 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
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The Winter Skies • An (indoor) stargaze by Dan Roth Jupiter Venus
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 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. Alcor Mizar Not to scale
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.
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. ...and some calculations • 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 • For Sirius (8 min exp): • Trail length is 9mm • (4125.3”/mm)*(9mm) = 37127.7” or about 10 degrees
The Big Dipper (handle) Kodak TX 400, Pentax K1000, f/2, 10 sec exp, tripod w/ 50mm lens The Big Dipper (bowl) Kodak TX 400, Pentax K1000, f/2, 20 sec exp, tripod w/ 50mm lens Leo (body) Kodak TX 400, Pentax K1000, f/2, 20 sec exp, tripod w/ 75-205mm zoom lens Leo (head) Kodak TX 400, Pentax K1000, f/2, 20 sec exp, tripod w/ 75-205mm zoom lens Orion Trails Kodak TX 400, Pentax K1000, f/4, 4 min exp, tripod w/ 50mm lens Sirius Trails Kodak TX 400, Pentax K1000, f//22, 8 min exp, tripod w/ 50mm lens Photo Technical Info. • Jupiter and Venus • Rite Aid Color Film (ASA 200), Pentax Spotmatic, f/1.8, 5 sec exp, tripod w/55mm lens • Orion • Kodak TX 400, Pentax K1000, f/2, 60 sec exp, piggypack w/ 75-205mm zoom lens • Canis Major • Kodak TX 400, Pentax K1000, f/2, 60 sec exp, piggypack w/ 75-205mm zoom lens • Gemini • Kodak TX 400, Pentax K1000, f/2, 20 sec exp, tripod w/ 50mm lens • Taurus/Pleiades • Kodak TX 400, Pentax K1000, f/2, 30 sec exp, tripod w/ 50mm lens • Taurus • Kodak TX 400, Pentax K1000, f/3.8, 5 sec exp, tripod w/ 75-205mm zoom lens • The Pleiades • Kodak TX 400, Pentax K1000, 120 sec exp, prime focus