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Hi Howard,

    You're right, I didn't make myself very clear there. I must remember to 
engage my brain before putting my fingers in motion. :{)

    I know the clock in my laptop doesn't keep good time. So, what I do is I 
synchronize the clock right before I go out to do my astronomy at home, or I 
synchronize it right before I load it up into the car to go to the star 
party. I also run only the programs absolutely necessary for my planned 
astronomy for the evening. Of course, I wonder if it is the displayed time 
that is bad and not the internal time. I would think that a timing chip 
running at the speed of modern computers would keep the time spot on. 
However, you're probably right that the displayed time is not accurate at 
all. Since the time on my laptop is only displayed to the minute. I don't 
know how SoftwareBisque handles the time it gets for the FITS header CCDSoft 
uses.

    Yes, we do need to discuss this more at the next ATM meeting.

Tandy W. Carter Jr.
[log in to unmask]
http://home.att.net/~tandy.carter/
----- Original Message ----- 
From: "Howard L. Cohen" <[log in to unmask]>
To: "Tandy W. Carter Jr." <[log in to unmask]>; 
<[log in to unmask]>
Sent: Tuesday, January 23, 2007 10:46 PM
Subject: Re: Up-Coming Occultation


> Tandy,
>
> I guess I must have misinterpreted your statement about planet magnitudes. 
> You originally wrote, "Some of the planets are on the order of Magnitude 
> 4."  I did not take this to mean some are fainter.  Note that even Uranus 
> is much, much fainter than mag.4 -- 
> its magnitude of about +6 is two mag. fainter which means Uranus is about 
> 6 times fainter than mag. +4.  Similarly, Neptune is about 40x fainter if 
> mag. +8 and Pluto at mag. +14 is 10,000x fainter.
>
> I have not run extensive test on PC clocks but the error is a function of 
> what computer tasks are running so the correction can be irregular.  I 
> have noticed that after only a few seconds, the clock correction is 
> sometimes as large as 0.5 sec.  I suppose it is possible that the computer 
> clock would be OK if corrected just before and after the event but it may 
> not be possible to know the exact correction during the event since the 
> correction is not predictable.
>
> I hope we can discuss things further at the next ATM meeting.  I am also 
> hoping Dr. John Oliver will be there to help provide further advice.  He 
> can probably tell you more about feeding WWV to your computer since we 
> used to do this when he and I did occultation work some years ago.
>
> Howard

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