From: Mark Gaffney <markgaffney@mac.com>

Date: August 9, 2008 4:53:54 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Great Red Spot...?

Hi Milton, You`re right! I have the Sky & Telescope site Bookmarked- I should have checked it. It was in very fine print in the magazine & my eyes aren`t what they used to be at 51 now! The dust appears mostly on one shot & not the other so I`m suspecting the secondary mirror again which is open to the air as I change from the eyepiece to the camera which I do numerous times. Thanks again! Mark. 

On Saturday, August 09, 2008, at 09:15AM, "Milton Aupperle" <milton@outcastsoft.com> wrote:

Hi Mark;

I don't know about the GSR from Australia, but this site

http://www.skyandtelescope.com/observing/objects/planets/ 

Transit_Times_of_Jupiters_Red_Spot.html

indicates it's at a longitude of 127°

Those circular "darker" halos on Jupiter are dust spots on the CCD or  

possibly the IR filter. You need to either blow them off with  

compressed air or a soft camel hair camera / lens brush. For longer  

focal lengths you need to keep the dust off.

Hope that helps..

Milton J. Aupperle

President

ASC - Aupperle Services and Contracting

Mac Software (Drivers, Components and Application) Specialist

#916, 742 Kingsmere Crescent S.W.

Calgary Alberta T2V2H8

1-(403)-453-1624

milton@outcastsoft.com

www.outcastsoft.com

On 9-Aug-08, at 9:44 AM, Mark Gaffney wrote:

I was disappointed not to catch the transit of the GRS. According  

to Australian Sky & Telescope the transit should`ve happened at  

around 11.47 pm tonight. That`s 21.22 pm + 53 minutes or 1 & 2/3  

minutes late for every degree west of 121 degrees. This apparently  

assumes the Red Spot is at Jovian System II Longitude 121 degrees  

and hasn`t moved elsewhere. This is what I`m getting for 11.32 &  

11.41pm. Maybe I was a little early? Mark.