NGC 55 String of Pearls Galaxy under Sydney Skies

[Startrek (Martin)]

It was great to see some consecutive clear nights in Sydney last weekend without the moon around.Captured NGC 55 for the first time in Sydney under Bortle 7/8 Skies ( I’ve captured this Galaxy many times before but down south under dark skies )

6” f6 Bintel GSO newt
Skywatcher EQ6-R pro mount
ZWO 2600MC cooled to -10C Gain 100
Protective window is an Internal UV/ IR cut filter
185 x 90 sec dithered guided subs ( over 2 nights )
40 x Flats
60 x Bias
PHD2 Multistar guiding ( 0.55 to 0.65 arc sec total )
EQMOD, Stellarium, APT
Stacked in DSS
Processed in Startools V1.8 OSC linear data set

As expected loads and loads of LP noise gradient to deal with even with shortish subs.With a few hours of processing I managed to scrap together some sort of an image

Original frame version
Crop version

Comments most welcome

Thanks

Martin

[Stephane]

Great effort Martin. You got some nice colours and detail, especially in the galaxy itself. Personally I prefer the cropped version. The cluster of galaxies on the right of the two bright stars bottom-left is quite nice too.

Interesting, I also went for 90 sec subs on this one. For this camera, I’ve so far found it to be a bit of a sweet spot when unfiltered, but still experimenting. Still thinking of going mono in 2023?

[Dave882 (David)]

Nice work Martin! Really good colour and detail through the core. Only 3hrs of integration and if I remember correctly it was quite windy and poor seeing for much of that. So that’s a wonderful result!

[Startrek (Martin)]

Originally Posted by Stephane

Great effort Martin. You got some nice colours and detail, especially in the galaxy itself. Personally I prefer the cropped version. The cluster of galaxies on the right of the two bright stars bottom-left is quite nice too.

Interesting, I also went for 90 sec subs on this one. For this camera, I’ve so far found it to be a bit of a sweet spot when unfiltered, but still experimenting. Still thinking of going mono in 2023?

Thanks Stephane
I massaged some sort of image out of the heavy gradient
The gradient was that bad under Bortle 8 that I had to use FilmDev to stretch the image rather than an AutoDev with a region of interest.
You could probably drop down to 60 sec subs for Galaxy imaging with your 8” and it has significantly more light pull than my humble 6” with longer focal length and aperture
Yes Mono is the best way forward for both broadband and narrowband as your capturing so much more signal from each sub.For Broadband under Bortle 8 LP your still going to get heavy gradient with Mono , there’s no getting around that but your signal is way up there compared to OSC and therefore so much more depth and detail for similar integration time.
As for Narrowband with Mono , it blows OSC out of the water under Bortle 8 especially with high quality 3nm filters

Cheers
Martin

[Startrek (Martin)]

Originally Posted by Dave882

Nice work Martin! Really good colour and detail through the core. Only 3hrs of integration and if I remember correctly it was quite windy and poor seeing for much of that. So that’s a wonderful result!

Thanks Dave
It’s certainly a struggle with OSC and heavy LP imaging a mag 8 Galaxy with a 6” reflector
The wind did settle later on in the evening, but I always hang up my 2 Bunnings polytarps anyway to block my neighbours Las Vegas flood lights that blast my yard , a double shot of light pollution for good measure

Cheers
Martin

[Addos (Adam)]

nice shot martin! interesting shape on this one isnt it?

[Startrek (Martin)]

Originally Posted by Addos

nice shot martin! interesting shape on this one isnt it?

Thanks Adam,
Shame it’s not tilted so we could see the spirals and core

It’s a dim one for my rig in heavy LP , magnitude 8 , 6.5 million light years from Earth and 70,000 light years in width , a tad smaller than our Milky Way Galaxy

Still a fascinating object with some unique details

Cheers
Martin

[Benjamin (Ben)]

Very nice Would be curious to see what this Magellanic Spiral galaxy might look like tilted or face on. Something like the LMC perhaps?

[Startrek (Martin)]

Originally Posted by Benjamin

Very nice Would be curious to see what this Magellanic Spiral galaxy might look like tilted or face on. Something like the LMC perhaps?

Thanks Ben 👍