Stellar Shot of the Week

Larry Ammann captured this striking shot of the Andromeda galaxy (M31) with his SVX140T. This barred spiral galaxy is located approximately 2.5 million light-years away from Earth and has a rough diameter of 152,000 light-years. It has a 50% chance of colliding with our Milky Way galaxy sometime in the next 10 billion years. This merger could end up forming a giant elliptical galaxy, or a large lenticular galaxy.

According to Larry: “Here is yet another image of M31 taken with my SVX140T and ASI2400MC one-shot color camera. I decided to shoot this target again to celebrate the 100th anniversary of Edwin Hubble’s discovery of a Cepheid variable in M31. He was then able to show that M31 and other “spiral nebulae” are individual galaxies far removed from the Milky Way. This discovery marks the beginning of modern cosmology.”

“One hundred years ago Edwin Hubble identified a Cepheid variable in Messier 31. Using the Period-Luminosity relationship discovered earlier in the 20th century by Henrietta Leavitt, Hubble determined that M31 was far outside the limits of the Milky Way's dimensions. This decisively ended the Great Debate about the nature of "spiral nebulae" and started a revolution in our understanding of the universe. Today our society is still coming to grips with the scientific and philosophical ramifications of these discoveries. Current estimates of its distance place M31 about 2.5 million light years away with a diameter around 150,000 light years, making it the largest galaxy in the Local Group that includes the Milky Way and M33. When the photons displayed in this image left M31, there were no humans on Earth, just several species of hominids learning to survive and adapt. During those photons' journey, homo sapiens eventually evolved and developed technologies that enabled me to capture them with my telescope and camera. We can only wonder what has been happening in M31 with its hundreds of billions of stars during that time.”

Other Designations: Andromeda Galaxy, Messier 31, M31.

Details:

Telescope: SVX140T+SFFX-2 (938mm f/6.7)

Camera: ASI2400MC (1.3"/pixel on the SVX140T)

Mount: Paramount MX+ (upgraded)

Focuser/rotator: Moonlite Nitecrawler

Filter: Antlia dual-band HaOIII

Subs: 15x300 secs HaOIII, 116x120 secs unfiltered

Telescope and camera control: TheSkyX on a mac mini

Location: southern OK, Bortle 3

Processing: Pixinsight, Affinity Photo 2

References:

Wikipedia contributors. (2025, August 20). Andromeda Galaxy. Wikipedia. https://en.wikipedia.org/wiki/Andromeda_Galaxy