Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: JohnH on Feb 04, 2025, 15:58:46

Title: M33 (Bortle 7)
Post by: JohnH on Feb 04, 2025, 15:58:46
(https://cdn.astrobin.com/thumbs/CAHX3LEKhG_A_1824x0_HdHQ5gSi.jpg)

This is a Bortle 7 image of M33. In Sky Safari it is called The Pinwheel Galaxy (but I thought that that applied to another object?) also known, for obvious reasons as The Triangulum Galaxy.

On Astrobin the image is plate solved: Link to Astrobin page (https://cdn.astrobin.com/thumbs/CAHX3LEKhG_A_1824x0_HdHQ5gSi.jpg)

I imaged it on 23rd and 30th January and 1st February - when I checked the subframes I discovered that it was disappearing behind the wall of my observatory and I lost a lot of them.

My normal setup was used:

Sharpstar 15028 HNT (150mm f2.8) Image scale ~ 1.87 arc" per pixel - the image is slightly cropped to remove vignetting in the corners.

Camera: ZWO ASI1600MM Pro (at -10C)

Mount iOptron CEM 25P

ASIAir Pro, ZWO Filter wheel and ZWO Electronic Automated Focuser.

Sub-exposures used (more than I thought):

HaO: 300 sec x 25
R: 120 sec x 33
G: 60 sec x 60
B: 60 sec x 33 and 75 sec x 10
Ha: 240 sec x 38

Astrobin says this amounts to 7 hrs 28 mins and 30 secs in total and the average Moon phase was 15.68%

Processing: Pixinsight, Affinity Photo 2 and GraXpert.

Regards to all,

John
Title: Re: M33 (Bortle 7)
Post by: Carole on Feb 04, 2025, 18:59:47
AS I said on Whatsapp, that's a fine result from Bromley.  It is probably lacking in whatever the Luminancce would bring, but as we both know Lum is not practical from Bromley.