M31 Andromeda Galaxy

M31 Andromeda Galaxy HCH RaSC LPro
M31 Andromeda; Captured at HCH, Colorado Springs, Colorado; 20 November 2022

Fun facts

M31 Andromeda Galaxy is a barred spiral galaxy and is the closest major galaxy to the Milky Way, where the Solar System resides. It was originally named the Andromeda Nebula and is cataloged as Messier 31, M31, and NGC 224. Andromeda has a diameter of about 46.56 kiloparsecs (152,000 light-years) and is approximately 765 kpc (2.5 million light-years) from Earth. 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 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 was more massive than the Milky Way by a margin of some 25% to 50%. The Andromeda Galaxy has a diameter of about 46.56 kpc (152,000 ly), making it the largest member of the Local Group of galaxies in terms of extension.

The Milky Way and Andromeda galaxies are expected to collide in around 4–5 billion years, merging to potentially 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, and is visible to the naked eye from Earth on moonless nights, even when viewed from areas with moderate light pollution.

Other Catalog Designations: M31, NGC 224
Subtype: Barred Spiral Galaxy
Distance from Earth: 2.5 million light years
Size: 152,000 light years
Constellation: Andromeda

{ From: https://en.wikipedia.org/wiki/Andromeda_Galaxy

Capture Notes

Debated about imaging the NGC1909 Witches Head Nebula, but decided on M31 Andromeda as it was at its peak of viewing hours while NGC1909 has opportunities until March, allowing a dark skies opportunity (which never happened from September 2022 until June 2023!). Had some strange issues with start-up, perhaps because I reaccomplished the framing & mosaic tool in the sequence plan – SGP failed to save the image to disk, then wouldn’t start the PHD2 calibration process. I ended up recreating the entire sequence on the laptop from its RaAskarRC135E profile – needed to go into SGP and clean up the equipment profiles and create a clean RaSC with RC135E, so there’s no doubt on which equipment is included in the profile. Also, at the end of the session, although it theoretically had 45 minutes until the 20 degree horizon, ran into the corner of the house at about 0215 – I need to determine what the “real” horizon is for the west side of HCH patio shooting (turns out that, depending upon the azimuth, it is as much as 30 degrees).


Polar alignment: QHYCCD camera (controlled by Polemaster)
Imaging stream: Askar FRA600, Canon EOS Ra with Optolong LPro light pollution filter
Mount: Rainbow Astro RC-135E (controlled by iHubo)
Autoguider: Orion 60mm Multi-Use Guide Scope, Orion StarShoot AutoGuider Pro Mono Astrophotography Camera (controlled by PHD2)
Equipment controlled by HP Probook (DSO CTRL 1) running Sequence Generator Pro v3.2.0.660. 

Capture & processing notes

Sequence plan: ISO1600, 137x3min; captured 20Nov2022, 1843MDT – 21Nov2022, 0211MST; Total=6:51hrs. 

Capture: 20 November 2022
Shooting location: Colorado Springs, Colorado
Processing: Stacked in APP, processed in LR/PS.