Wednesday, September 8, 2010

Running Towards Orion

The constellation Orion (“The Hunter”) at this time of year hangs low in the eastern sky before daybreak. Nearby everyone recognizes the constellation from the 3 classic stars that comprise his belt (Mintaka, Alnilam, and Alnitak).

(Image credits here)

This morning I headed out with the bride at 5:40 AM, she run/walking 2 miles and me adding the Harshman Road loop for a total of 5 miles. I should acknowledge today as a milestone—it’s our first run together in years. She was an avid runner prior to having children, but developed hip and knee issues afterwards and was unable to run, only walk. But today she decided to give it a try, with no apparent ill effects, so perhaps the issue is distance- and intensity-dependent. Keeping my fingers crossed….

But I digress. I wanted to focus on Orion and specifically the nearby star Sirius. I was fascinated with the clarity of Orion this morning. The star in his right (viewer’s left) shoulder, Betelgeuse, is visibly reddish and is the 10th brightest star in the heavens. Rigel is the brightest star in the constellation proper and the 6th brightest star in the sky, appearing down at Orion’s left knee. His sword, hanging down from his belt, was clearly visible.

Ah, and Sirius! This is the brightest star in the sky. You find it by locating Orion’s belt, then drawing a line from his right side (viewer’s left) “down” some 5 or so belt-widths, where you can’t miss Sirius. It unmistakably twinkles. Per the Crystalinks website,

To the naked eye, it often appears to be flashing with red/white/blue hues when near the horizon.

Sirius is some 8.6 light years away, meaning that the photons sent our way from that star take over 8 years just to reach us. I cannot imagine the number of photons emitted…figure that Sirius radiates in all directions, not just towards Earth.

Earth’s diameter as a percentage of the arc of space into which Sirius radiates is vanishingly miniscule. Then what light reaches earth is spread over the entire Sirius-facing surface of our planet. Some of those very photons enter my eyes (as well as those of all other observers), stimulate my retina, and create the brain image I've been taught to recognize as Sirius. That chain of events is almost too much to fathom.

All these thoughts while I am running, and seeing the constellation Orion and the star Sirius fade dimmer and dimmer as the sunrise approaches.  Orion fades away. Then a truck passes, the horizon is interrupted by a row of trees; I look up again and can no longer see Sirius.

Till tomorrow, my celestial friend.

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