17 May 2000
Venus-Jupiter in a very close conjunction!
by Lorenzo Comolli

17 May 2000, h 10.30 UT: one of the closest conjunctions of this years, the centers of the planets were at 40", the borders only at 18"!!! Vesus was of 10" diameter and Jupiter of 33", the magnitudes respectively -3.8 and -1.8.
You will say: very interesting!
But here is the problem: the event was at midday and at a distance from the Sun of 6°48'! Here in Tradate (VA, Italy) the day was sunny but not very transparent.

My idea was to register in some way the event: the solution was nor the photography nor the CCD, but the Vixen B05-3M b/n video camera, just buyed by my astronomical group, GAT. I've recorded some images from 10.10 UT to 10.50 UT. The telescope used was my Meade SC 8", with a diaphragm of 3 centimeters and a shading tube that prevent the Sun light to enter in the telescope. The better images went at about 10.47 UT when the haze become less evident. On the video cassette Venus is evident, but Jupiter is at the limit of visibility. The size of the sky visible with that configuration was 7'x5', with a resolution of about 1" per pixel.

But how to make more evident the conjunction? The solution come from digital elaboration: I've digitalized 20 frames with an old video digitalizer of GAT and I've elaborated them with Qmips, making a sum. The result, retouched in Photoshop, was put in false colours, that reproduce wat could be visible at the eyepiece of the telescope. In comparison to the film, the image obtained is 100 times better! Here is the result:

At left: the result of the elaboration of 20 frames taken at about 10.47 UT. Jupiter is visible under Venus at right. The maximum approach was at 10.30 UT, but the images were worse because of the haze.
At right: digital simulation of the event, showed at 10.47 UT.

Also a MOV animation (59Kb) is avaiable to show the path of Jupiter respect to Venus from 10.00 to 11.00 UT. Click here.

Finally a storical note: in 2 b.C. there was a similar close conjunction between Venus and Jupiter, more easy to observe, event that is considered a possible explanation fot the "Bethlehem star".

For any comments (also about my bad English), write to: comolli@libero.it

HTML Editing and Publishing by Lorenzo Comolli. Email me at comolli@libero.it.
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