I saw movement in both stars on two different occasions and I was looking at stars not asteroids, comets, or alien vessels.

Refraction is just one thing that affects the tracking rate. OTA flexure occurs even in refractors. Mis-Polar alignment, however slight, can affect tracking rate over a duration of minutes. -Ray

Yes, APCC Pro can do this. -Ray Gralak Author of Astro-Physics Command Center (APCC) Author of PEMPro: http://www.ccdware.com Author of Astro-Physics V2 ASCOM Driver:

APCC Pro -Ray Gralak Author of Astro-Physics Command Center (APCC) Author of PEMPro: http://www.ccdware.com Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver Author of

Hi John, I am currently using a 106mm refractor on my Mach1 mounted on a 10" concrete pier in a domed observatory. I am running with pre-loaded PEC on. Jon

Thanks for the explanation Ray. But, if the stars "apparent motion" is slower than sidereal, would that not show up as star movement in an EASTERLY direction while drift aligning as the star fall

Peter. I do my drift alignment on a star that is very near the Meridian and Celestial Equator for azimuth and another about 20 degrees above the eastern horizon on the celestial equator as most

No mirror shift. I use a refractor.

Hi Everyone, I recently purchased a 2010 Mach1GTO mount and took it out for the first time this weekend. Polar alignment and tracking were absolutely beautiful with one minor issue. The latitude

I've been playing around with TheSkyX and using its native driver (I'll get to the ASCOM driver later...). Before upgrading to TheSkyX, using TheSky 6, when I powered my mount up it did not start

For the AP Staff. I purchased my Mach 1 about Nov 2012 and just found my missing registration card. Can I still send it in to register my equipment?? Gregory Gig Harbor, WA.

Which version of APCC has modeling software plz ? Thanks Suresh [Non-text portions of this message have been removed]

I have similar experience as Jon seeing drift in RA when unguided. Can APCC correct this? Thank you. Donghun

I am surprised too, as in that someone even tried this! Almost 100% of the time, one would remove the power. Likely why in 15 or so years this has never come up for discusssion to my recollection.

Correct! The *apparent* movement rate of stars is slower than sidereal because of refraction. This is mostly true. One may get lucky in certain parts of the sky where telescope flexure, mis-polar

As part of my personal learning curve, I have my 900GTO/GTOCP3/Q/4.17 set up next to my desk. No OTA or counterweight shaft. Four days ago I used the hand controller to set the tracking rate to

A star diameter is pretty small if properly focused with good optics.  Are you sure that PEM is enabled?  As I recall, it defaults to off even though it comes pre-programmed. If you saw this

Jon, What kind of telescope where you using, and what is its focal length? Is the mount on a permanent pier or a tripod? Are you accounting for any residual peridoc error? Where the two stars near

Correct me if I'm wrong. I believe stars do not move exactly at Sideral rate if they are not near the Meridian. So if you center the star 2 or 3 hours away from the Meridian and came back in 30

Jon, What kind of telescope are you using? Is it possible the drift you are seeing is really a mechanical shift in the scope, eg, SCT mirror movement? Regards, Chip Gentry Austin, TX, Earth