venus transit path terminology

[sil]

Like many people I was able to get some nice photos of the transit of venus (over 1,400 covering the whole event with a dslr only, no scope/mount).

As we know, viewing the transit with the (protected) naked eye venus made an inverted U shape (for us Aussies) across the sun's disc. If you account for the rotation of the earth/sun and "fix" the sun from apparently rotating then venus tracks straight across the face.

What I've been trying to find out for weeks and failing (even observatories I've contacted are stumped) is what are the scientific names for those two path types? "The curved path" and the "straight path after accounting for rotation" are not very elegant or explanatory. Everything in science seems to be given at least one name and there must be names for these two types of paths that when spoken to someone in the field they know exactly what you refer to. For example "analemma" is an exact term for a type of path the sun make and you only have to speak the word for someone to understand without having to then explain it. I have seen different sites try to use their own terminology to label the two paths but mostly they just don't.

So please put me out of my misery oh wise ones, what are the scientific terms for the two types of transit paths?


Refer to my image of both paths:
http://i256.photobucket.com/albums/hh180/pelmensb/VenusTransit2012-pairlores.jpg

[Blue Skies]

I don't think there are any different terms. I've certainly never heard of any difference, the track has always been straight. All the photos/images of any transit in the past (and I've seen a few Mercury transit ones as well) are always straight. That's why you can't find the term you think exists. I know you're frustrated by not being able to find an explanation for your results but I don't think it lies with the motion of the planets.

P.S. On reflection, what I would do is rather than try and get a verbal kind of response - since it's not been successful so far for you - is to immerse yourself in as much literature on transits and eclipses that you can lay you hands on. Include historical observations, celestial mechanics (as in how eclipses/transits come about) and other photos. Become the expert yourself. Hopefully along the way you'll find the answer you're looking for. It will be a journey as important as the destination.

[sil]

I have been trying to find the answer and trawling books, sites etc. I thought it would be a straight forward question since a lot about astronomy depends on points of view. As everything is in motion paths and orientations change, we use equatorial mounts to counter this in viewing/astrophotography. It seemed a logical assumption that there were common terms to allow a common frame of reference when comparing observations. I'm very much a newbie to astronomy and am slowly learning.

My main immediate reason for trying to define the path terms is because I'm going to make and frame some prints of my photos of the transit and wanted to print labels for the different paths. Even on sites and in books devoted to the transit of venus the two apparent path shapes are described but not really named anything.

The best labels I've been able to come up with are the "horizon view" and the "equatorial view". Horizon view because it's the shape of the curved path in relation to the horizon when observing. Equatorial view because you rotate with the equatorial to essentially stay "fixed" in relation to the roll of the sun giving the straight path. Maybe "ecliptic view" is more appropriate, I'm not sure. I was hoping I'd get a flood of responses with those same labels to know I was on the right track. I've still got a bit more work to do on my transit photos before I make my prints and I'm still searching for answers and learning. The transit has really inspired me to just get outside and start observing, it's really enjoyable.

cheers