care for a dip?

I hope you can see this alright, despite it being so dark.  A late drive with a clear night sky took me far enough away from the city lights, that I pulled over and took pics of the stars from a corn field.  I used a tripod and a wireless remote control.  The manual focus was preset to infinity.  Exif data: 20mm, 30.0s, f/4.5, ISO 400.

This part of the sky was the big dipper, which is one of the easiest constellations to find.  No telescope required!  I hope to learn more about classic astronomy, but we all have to start somewhere, right?

First, I'll tell you about the picture, and then I want to point out a couple of things.

These stars were the brightest, but there were many others that showed up, even though they were not as bright.  I found that distracting, so to minimize the clutter, I copied the photograph, and on the second image, I blacked out most of the stars, and then made a composite of the two.

After that, I searched online to find the names of these stars and voila! I discovered that what I always assumed was one star in the handle was actually two!  The second spot from the end of the big dipper's handle is a binary cluster of stars that is difficult to discern from any area where we do not have enough darkness in the night sky.  Did you already know about those two stars?  Their names are Mizar and Alcor, but sometimes they're called the Horse and Rider.  It is said that ancient Romans used Alcor to test a warrior's eyesight.  (For me, this "Horse and Rider" was the single most exciting thing about this pic.)

On the opposite of the Big Dipper's handle, we can use the last two points, Merak and Dubhe to point us in the direction of the North star (Polaris).  The distance from the constellation is approximately five times the distance between the optical space between these two stars.  Here's another easy way to find it: stretch yout your arm and open your hand wide; the distance between your thumb and pinkie is about the space between the lip of the Big Dipper and the North star.

For more about Sky Watch Friday, visit http://skyley.blogspot.com/ .

transit of venus

[click on image to enlarge]

Bob and Carol are friends of mine.  They teamed up to create an excellent photograph of Tuesday night's Venus Transit.  Bob is our local science guru, and he used this technique to cast the image of the sun onto a piece of white cardboard.  Carol snapped the pic with her compact point & shoot.  Theirs is the largest globe in this collage of four sun pics.  See the dot at the very bottom?  That's not the sun's bellybutton; that's Venus!

I stumbled onto the other three images while fiddling with the camera as I tried to snap a pic of the sun with my Pentax K-x, a 55mm lens, and a #850 Infrared filter.  I shot the pics in raw, cropped aggressively, and then used Picasa to try to correct the color balance.  That first picture, the magenta ring with psychedelic focal zoom is actually closer to the original, unedited pics than my yellower suns.  Again, special thanks to Carol for letting me download her photograph!

The Transit of Venus happened eight years ago in 2004 and then again just this week, but won't appear again for another 105 years.  That's because Venus' orbit has a slightly different tilt than the earth's.

Friends, I couldn't capture the kind of image I had hoped for, but it was fun to try.  I hope to fiddle around again with sun pictures and see what develops.