Sunday, January 5, 2014

It is Venus Weather!


When the weather permits, every winter we can perform an astronomical observation that almost seems impossible.  If you know where to look, it is possible to observe the planet Venus with your naked eyes in full daylight!  You will need to know a few things to accomplish this feat...
Venus Anadyomene - Theodore Chasseriau
...and she'll probably need a jacket.

These cool clear winter days, as well as the astronomical position of the planets Venus and Earth will now allow us to see Venus in daylight. The bright “star” in the west just after sunset is the planet Venus.  If you have a small telescope or good pair of binoculars you can see that this “star” is a little crescent.  Even though the whole disk is not illuminated this planet is extremely bright due to the planets orbit bringing it closest to the Earth.

 
This is a Diagram of Where the Planets are...



This image I found on the Universtoday.com site illustrates this nicely.

 

 We have accomplished this easily several time in the last few clear weekends.  There are a couple of things you need to know to perform this feat. 

First, the planet is in close proximity to the sun in the sky.  You need to be real careful not to look at the sun, especially with binoculars or a telescope.  THIS WILL PERMANENTLY DAMAGE YOUR EYES! 

To avoid this stand in the shadow of a building or other structure looking south so the sun is hidden to your right-hand side (this also protects you as the sun moves across the sky to the west towards sunset - it will not emerge from behind the structure and keeps it out of site)

Sun is behind the roof line to the right

BTW - This picture is actually of the Comet McNaught I spotted in 2007 using this technique... If you can see it in this image please let me know I never found it but definitely saw it!

Secondly, You will need a clear blue sky!  Finally, you will need to approximately how far behind the sun is it?   There are some smartphone apps that will help...
Free from Android Store

 

With this tool, you simply start the app and aim your phone to the sky until the planet Venus lines up and the now shaded sun line up. 


Google Sky in Action 


Now you are ready to spot it. The best way to start is to use a pair of binoculars to locate it by systematically scanning the sky. If you are using binoculars focus them on a distant object, a jet contrail or if the moon is visible work great.  

Once you spot it, take note of the angle and move the binoculars to the horizon, and note a land mark straight below where the point you spotted it.  This also helps show someone else where to look!
Venus in Daylight ca.11:32AM PST 12/22/13 - (West is left)


Also, can you see the crescent shape?  No this is not the Moon.  If you rotate the view 180 degrees it is the same crescent you see in the first diagram's "Evening Sky" side of the diagram. All you'll need are a good pair of binoculars and a steady hand or a telescope on a tripod or other steady surface to see the tiny crescent.  

Now that you know where it is, try with your eyes only! 
So to see it without an optical aid,  there is a visual skill that you will need to learn.  Looking into a clear blue sky you will need to train your eyes to look into infinity!  The contrail or other object in the sky will help you train your eyes as you did the binocular focus, only the eye will try to focus and won't stick at any focal length like the binoculars do.  But the trick is not to look at anything close to change the eye's focus, we have used a paper tube to help focus attention to a small area of sky .  If there is a well-placed contrail or bird happens to fly by it will help train your eyes as well.   Once you train your eyes to focus at infinity, and find it once, you can’t help but see it. It looks like a little star up in the blue daytime sky. 

Hint: You may need to take off your sunglasses as you will need all the light gathering power your eyes have.

We have not been able to photograph it with a digital camera alone.  If you ever tried to photograph the moon without a telephoto, you know it will only show up as a dot so the chance of getting a star in blues sky is next to impossible, without at least some magnification.  The optical telephoto is pretty weak in my camera, and the digital zoom is useless for this, even when we could see it in the viewfinder, we never found a setting for the exposure. 

But, as you can see, but we were able to successfully take a few pictures through a small telescope simply shooting it through the eyepiece!  I used my little Celestron First Scope  (less the solar filter) to photograph these.   There is a lot of trial and error to get the autofocus to focus the telescope's image not the eyepiece, and the optical axis has a dark spot dead center that is due to the secondary mirror of this scope. Finding it with this much magnification that takes some doing as you only get to look at a small area of sky at a time.  Also, these images are "mirror images" due to the telescope's optics.
 
Here are some more Eyepiece Views, the large blue circle and spots are artifacts from the telescope.  It is not easy to line up the camera and the eyepiece, but it can be made to work.
 
 
 


Pretty cool huh?

 UPDATE: 1/6/2014. The crescent of Venus is, greatly elongated but is less than 10 Degrees from the Sun now, be extremely careful...or wait for it to appear once again in the morning sky!