On Apr 10, 2025, at 5:01?AM, Gabriel Wiklund via groups.io <gabriel.wiklundholeshot@...> wrote:

?

[Edited Message Follows]

Another example of the improvement thanks to Multi-Star Guiding:

Best 1.5 minute guiding period from my last session: 0.60" arc seconds total RMS (!)?

?

<Autoguiding 7 April.png>

?

0.60" is about the limit of what my guiding setup can measure.

?

Even though Multi-Star guiding works well you can't choose the main star. If PHD2 picks a star at the opposite side of the frame with respect to the target the object will drift out of the frame pretty quickly if you are high above the horizon close to north/south, places we should stay away from anyway.

?

The optimal strategy would be to use a Rotator + OAG then the Multi-Star algorithm could pick any star and the object would not drift

from the field of view, not even because of guidescope flexure, the OAG would keep it locked.

?

Before i used an OAG on my 8" imaging newtonian the object would actually creep in the frame and cause walking noise despite the fact the guidescope was correctly mounted. So even on an Equatorial mount you can run in to such issues even if you are locked on the same guidestar the whole session.

?

Here is the result:

39.5 minutes (237x10s) on NGC 2146 - The Dusty Hand Galaxy.

?

This "skeletal hand" looking galaxy is located about 70 million light years from earth and it's shape is believed to be the result of a near

galactic collision.

?

On Astrobin:?

?

<39.5m NGC 2146 Reprocess2.png>

?

FWHM of the stack was about 2.60"

?

/Gabriel

?

?

?