Monday, August 18, 2014

Venus and Jupiter Conjunction 8/18/2014

  After predawn clouds thwarted my efforts to photograph Venus and Jupiter against a sunless sky, I had to go to plan B.  That plan, to photograph them through a telescope, had a much higher degree of difficulty.  It  would yield less aesthetically pleasing images and still require the clouds to part. 

  When I got off of work after sunrise the skies were still an impenetrable gray mass. But lighter skies in the direction of home gave me hope. 

  Finding the two planets during the day took some advance preparation.  I figured that the planets being just under 18 degrees from the Sun, would make them nearly impossible to spot through my telescope's low magnification finder scope.  So last night before work I aligned my scope's equatorial mount as close as I could with the Earth's axis of rotation.  That way I could zero in on the target by offsetting from an object that I could locate.  Luckily the Moon was in a much more favorable position for daylight observation and provided a reference point.  
   Through broken clouds I found the Moon just west of due south and 60 degrees above the horizon.  After finding it through the wide-field finder scope and the main telescope, I did some minor tweaking to the finder to ensure they were perfectly aligned.  Then I set the setting circles on the scope's mount to the Moon's coordinates, 4hrs 24mins of Right Ascension and verified declination of +17 degrees.  (Right Ascension is the angular distance measured eastward from the point where the Sun is at the Vernal Equinox, and Declination is the angular measure North (+) or South (-) of the celestial equator which is the projection of the Earth's equator onto the celestial sphere).  Then by swinging the telescope around to Right Ascension 8hr 40min and scanning up to +19 degrees declination I should have seen the planets through the eyepiece in the 1 degree field of view. That is if I had perfectly aligned the scope last night.  Miraculously I was only a little off but close enough that Venus appeared on the edge of the field of view.  A little fine tuning  brought both planets  into the field (Note: I never saw Jupiter but I knew where it was and aimed accordingly) and I was ready to remove the eyepiece and attach the camera.  Here are the results that illustrate the difficulty in finding the two brightest planets when they are in a less than perfect sky just 18 degrees away from the Sun. 
Only Venus is readily apparent 

Increasing contrast of the image makes Venus easier and Jupiter detectable

Inverted color image makes them a little easier to see.

Oddly passing clouds made them stand out more

    The modern equivalent of my 20 year old scope comes with automatic alignment  and a computer database with the positions of all the planets and thousands of stars, galaxies and nebulae.  All you would have to do after the alignment process would be to enter the object you want to observe and stand back as it scans right to it.  Funny thing is that the modern scope, with all that technology, cost the same as my analog telescope did two decades ago.

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