[AZ-Observing] Re: MESSIER 2 declination error

  • From: "AJ Crayon" <acrayon@xxxxxxx>
  • To: <az-observing@xxxxxxxxxxxxx>
  • Date: Tue, 29 Jul 2008 22:01:55 -0700

Stan, thanks for the report and glad to hear your system is OK.  BTW did you 
also check its NGC number, i.e. 7089.

AJ Crayon
Phoenix, AZ

----- Original Message ----- 
From: "Stan Gorodenski" <stanlep@xxxxxxxxxxxxx>
To: <az-observing@xxxxxxxxxxxxx>
Sent: Tuesday, July 29, 2008 9:12 PM
Subject: [AZ-Observing] Re: MESSIER 2 declination error


AJ,
I just powered up my Meade 16" f/10. I picked Arcturus as the first star
for it to slew to from the hand paddle. Sometimes I need to sync on the
first object and this is why I do this.  It took a GPS reading and
slewed to it. This night it was almost in the center of my old 20mm wide
angle Meade eyepiece and so I did not have to sync it. I then selected
M2 from the hand paddle. It slewed to it and, again, the globular was
almost in the center of the eyepiece. I had my doubts it would be so
accurate since it is is low in the horizon at this time of the night.

Meade's software on the 16" has no problem finding M2.
Stan

AJ Crayon wrote:

>Has anyone had problems locating M2 with digital setting circles or a GoTo 
>system?  This involves any of the electronic systems.
>I have run across declination errors with this entry on the XP4 Flash Sky 
>Commander digital setting circles and on Orions SynScan GoTo system. 
>Reason is because the declination is -0° 49' and the way computer hardware 
>handles -0.  Turns out most computers convert -0 to +0 resulting in 
>incorrect calculations.
>
>I corrected my version of XP4 with an update the the Messier catalog when 
>this was discovered some time ago.  I have just found the problem in the 
>SynScan system and notified Orion this morning.
>
>So, I ask, has anyone else had problems with their system finding M2?
>
>AJ Crayon
>Phoenix, AZ
>
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