M31 - 6 Panel Mosaic

Blessed be, SGP. :slight_smile: I don’t know that I’d even BEGIN to attempt mosaics…much less mosaics with 42 individual sets of data…without it.

6 panels, each panel is ~35x180s of R, G, and B, and ~55 ea of 30s, 60s, 120s, and 300s L, for something in the neighborhood of 72 total hours of exposure.

Stellarvue SV80ST, Mach-1 GTO, Orion LRGB filters in an SX Mini USB FW w/ QHY5 OAG, FeatherTouch focuser, Atik 414EX cooled to -10C each night. 10 nights of data between 9/5/19 and 10/5/19, from near Sparta, TN.

Processed in PixInsight.

Full resolution (4629x5024) version here.


Awesome! What a project. And such a great target for it.

1 Like


Awesome results on a huge project.


1 Like

72 hours…definitely not the right setup for M31 with such a small sensor :smile:
Color balance seems to be a little off, i’d expect it to be more blue in the outer parts and yellower in the core.
Nice work stitching together the panels!

I’m working on a 16 panel M31 mosaic right now myself…gonna be a hell to stitch them together:joy:

1 Like

Did you use PI for stitching panels and normalising backgrounds?
Nice work.
Ravenshead, UK

Yep. Everything was done in PI, save for adding the watermark. :slight_smile:

StarAlignment in Register/Union Mosaic mode to create a full-sized mosaic, then registered the individual panels against that, both with Frame Adaptation on, then GradientMergeMosaic (with LOTS of fiddling with feather radius, which wound up quite high).

Tried various combinations of BackgroundNeutralization before or after building the mosaic, depending on the data set.

Finally, later in the process, some masking and desaturation or histogram tweaks to handle isolated problem regions.