This is my second effort on a monochrome imaging of The Andromeda Galaxy M31.  My first last year was a LRGB_Ha that was OK (ish) but was never convinced that the Luminance was worth the effort/imaging time.  Plus the image had a somewhat persistent blue cast in some areas due (I believe) to the Optolong filters.  I've replaced my entire filter set since then although the LRGB are still Optolong (the new Dark serias of Antlia looks very interesting...).

This time around I was specifically looking for Ha and Oiii narrowband.  I was looking for the Oiii in particular due to the results of Bray Falls that he posted for M31.  However, the 2.5 hrs of Oiii data I captured wasn't sufficient to capture any of Oiii structures in the M31 spiral that Bray's image showed.  If you haven't before, you really need to go visit his gallery.  To give him credit, he has days (literally) of integration time in the Oiii, which indicates how faint those details are.

Once I determined that I wasn't going to get anything useful from the Oiii data and given the weather/imaging window was closing within the next couple of days, I went for some new RGB data to use with the Ha.

I'm still struggling to get a consistently good result in taming the core of M31.  If not managed, it will blow out all of the structural detail in and around the center by the time you stretch to get the detail in the mid/outer spiral brought up.  I didn't get something I thought was acceptable until my third different processing approach.

This will be the last imaging from my own OTA for a while.  My focuser is going into the manufacturer (Moonlite Telescope) for some TLC to address some things that have developed after being deployed outside for 3 years.  I'm also considering the same for my mount (a Paramount MyT).  I've never gotten the unguided exposures that others indicate should be expected from this mount regardless of how much effort I spend on getting an "Excellent PA" per TSX.  The most recent PEC tends to make me think that the mount needs something beyond just a clean and lube, but that is for SB to tell me.  Same issue asa the focuser, it has been living outside under a Telegizmo cover for the last three years so a little TLC is warranted.

I've got a backlog of Telescope Live datasets that I've not yet processed to fill the gap until my setup is reassembled and tested, so it is not that I won't be posting any new images.

Please like and comment, I enjoy the feedback and discussions on both the post processing and the data acquisition.

Thanks in advance!!!

CS
George


ref: https://en.wikipedia.org/wiki/Andromeda_Galaxy

The Andromeda Galaxy (IPA: /ænˈdrɒmɪdə/), also known as Messier 31, M31, or NGC 224 and originally the Andromeda Nebula (see below), is a barred spiral galaxy approximately 2.5 million light-years (770 kiloparsecs) from Earth and the nearest major galaxy to the Milky Way. The galaxy's name stems from the area of Earth's sky in which it appears, the constellation of Andromeda, which itself is named after the Ethiopian (or Phoenician) princess who was the wife of Perseus in Greek mythology.

The virial mass of the Andromeda Galaxy is of the same order of magnitude as that of the Milky Way, at 1 trillion solar masses (2.0×1042 kilograms). The mass of either galaxy is difficult to estimate with any accuracy, but it was long thought that the Andromeda Galaxy is more massive than the Milky Way by a margin of some 25% to 50%. This has been called into question by a 2018 study that cited a lower estimate on the mass of the Andromeda Galaxy, combined with preliminary reports on a 2019 study estimating a higher mass of the Milky Way.  The Andromeda Galaxy has a diameter of about 220,000 ly (67 kpc), making it the largest member of the Local Group in terms of extension, if not mass.[citation needed]

The number of stars contained in the Andromeda Galaxy is estimated at one trillion (1×1012), or roughly twice the number estimated for the Milky Way.

The Milky Way and Andromeda galaxies are expected to collide in around 4.5 billion years, merging to form a giant elliptical galaxy or a large lenticular galaxy. With an apparent magnitude of 3.4, the Andromeda Galaxy is among the brightest of the Messier objects, making it visible to the naked eye from Earth on moonless nights, even when viewed from areas with moderate light pollution.