Messier 104 – Sombrero Galaxy

Messier 104, widely known as the Sombrero Galaxy, is one of the most striking and recognizable deep-sky targets in the night sky. Situated roughly 28 million light-years away on the southern edge of the Virgo cluster, this unbarred spiral galaxy is viewed nearly edge-on (inclined at just 6 degrees to our line of sight). Its iconic appearance is defined by an unusually massive, bulbous central bulge of older stars and a remarkably sharp, dark dust lane slicing directly across its equator. The dust lane serves as a dense ring of molecular gas where active star formation occurs. M104 is also incredibly rich in globular clusters, hosting an estimated population of nearly 2,000, and conceals a supermassive black hole at its core weighing roughly one billion solar masses.

For astroimagers, M104 presents an exciting challenge with a highly rewarding payoff. Shining at magnitude 8.0, its high surface brightness makes it an easy target to locate, but its relatively small apparent size requires a longer focal length to truly tease out the fine structures of its famous equatorial dust lane.

When processing this target, the primary hurdle is dynamic range: you must balance the immense, brilliant halo of the bulbous central core to keep it from blowing out while simultaneously pulling out the crisp, subtle details hidden within the dust ring. Because it sits relatively low on the southern horizon for northern hemisphere observers near the Virgo-Corvus border, tracking it through a clear window of steady seeing is critical for capturing its sharpest details.

Post-processing was done with Pixinsight, starting with integration using WBPP. I processed it live on the AstroWorld TV YouTube channel . I performed different types of background gradient extraction methods, such as Graxpert and Multiscale Gradient Correction, but for this project, we went with the proven Dynamic Background Extraction process. For stretching the images to non-linear, we demonstrated Generalized Hyperbolic Stretch (GHS) and Multiscale Adaptive Stretch (MAS). We also utilized Russel Croman’s BlurXterminator to deconvolute the stars, StarXterminator to remove the stars in order to stretch them separately, and NoiseXterminator to reduce the noise from the images. We utilized several scripts such as ImageBlend, along with Seti Astro’s Find Background, and Star Stretch. In the final image, I decided on the MAS stretch for the luminance and RGB images and used LRGB Combination to merge the detailed luminance layer to the starless color image, finally bringing the stars back using Image Blend.

To view the video and see the process, click the link below: