A question

Has anyone heard of differential atmospheric refraction. I posed a question to the Tak uncensored yahoo group about violet halo on one side of Jupiter through my Tak. Like I am worried it may be a collimation issue, but all images of everything are sharp as.
One person replied he is getting similar and it is a atmospherice anomoly and he has been seeing it all this viewing season, it his case the USA. He said it is "differential atmospheric refraction".
Is anyone else noticing this or am I being fed a load of cobblers?
Incidentally it is noticable in my avatar.

Cheers.

Peter

[Vermin (Tom)]

There is an article in the latest S&T about atmospheric dispersion (aka differential atmospheric refraction), and how to correct it.

Is that article in the Australia S&T or is it the USA version.

cheers.

Peter

[gbeal]

Hi Peter,
not sure about your question directly, but I also wonder if you need to wriggle the RGB mixer within Registax. The RGB mixer , and RGB shift in the wrong position can give this sort of result (from the hard to discerne look I have had of your avatar),
Gary

[gbeal]

The article is in the US version anyway, not sure about the local one

I can actually discern the halo looking visually through my eyepieces, not very noticeable, but still there though.
you can see from the attached photo what I mean.

[ving (David)]

googling it came up with solutions.
of course I know nothing of the phenomena myself

Yeah but you have to be a physicist to understand it all. If it is something occuring normally I wont worry about it, but if it is an artifact within my Tak, I will most definitely worry about it. As for any solutions, let me have them please..I cant make head nor tail of the Google responses.

[Dave47tuc (David)]

This problem you see a lot.
Some people with, say high end eyepieces mistake this as
"oh my eyepiece is no good" Not so.

The purple halo and yellow halo on either side of say Jupiter is mainly is Atmospheric refraction.

Hope that helps.

[Vermin (Tom)]

Exfso, it is not a problem with your Tak, it is caused by different refraction angles of red and blue light through the atmosphere and depends upon the height of the object above the horizon.

It can be fixed by placing a wedge shaped prism in the light path, there is a variable commercial unit available for this (see July S&T for details).

[Starkler (Geoff)]

Thanks Dave

I noticed this when viewing through Julians mega-buck Astrophysics refractor and thought something was wrong with it .

Thanks guys, I dont have that particular months issue, and not too sure how to get the particular article if anyone can help it would be much appreciated.

Cheers.

Peter

[trufflehunter (Wayne Robinson)]

I've noticed it through the LX90. I thought it was the eyepiece (13mm Nagler or 8mm Radian). Now I can blame the atmosphere! Can't recall ever noticing it on the moon, strangely enough, where any residual chromatic abberations from the optic system would be very apparent... most obvious (if 'obvious' is the word!) with Jupiter

I also noticed it tonight through my Meade SN10, oh well just another problem caused by the atmosphere, cant fix that though.