M108 is a intermediate spiral galaxy, seen at a sharp angle to us, located about 24 million light years from us. The pink regions are ionized hydrogen gas, indicating star-forming regions.

An unusual feature in this striking galaxy is the set of gaseous arms, emanating from the central supermassive black hole. They are difficult to see in this image, appearing only as red streaks, fairly near to the center, on opposite sides of the center. These are super-heated gas, thought to be related to the action of the central black hole. Below is a little cutout of the central part of the galaxy, with the two anomalous arms circled.

The dominant blue color in the disk is from energetic young stars being formed in the arms of the galaxy; the yellow is from a combination of older stars inhabiting the core, and light from starburst happening there. The rust-colored stuff is dust swirling around the core of the galaxy. To the right of M106 in this photo is NGC 4248, a dwarf galaxy that is a satellite of M106. Below the bottom point of M106 is PGC 39615, another dwarf galaxy that is a satellite of M106. The entire field of the uncropped photo is about the same width as a full moon. As is often the case, the field in the uncropped images is littered with smaller (meaning far more distant) galaxies; I always like seeing how many galaxies there are in our universe! A special bonus is the distant galaxy cluster ClG J1217+4730, just above NGC 4248 in my photo, and just to the right of the upper corner of M106 (more easily seen in the full resolution, uncropped photo linked above); it is the collection of deep yellow dots, many of which are elongated, located about 3.2 billion light years from us.

M106 is a large galaxy, with a diameter of about 135,000 light years (a bit larger than our Milky Way).

Technical Information:

HaLRGB: 480:810:240:240:280 (a total of over 34 hours of light-frame exposure time); here's a chart showing the various subexposures I used in the image:

Hydrogen Alpha: 24 twenty-minute images
Luminance: 50 fifteen-minute and 20 three-minute
Red: 16 fifteen-minute
Green: 16 fifteen-minute
Blue: 14 twenty-minute
The luminance layer is a HDR blend of the 15-minute images and the three-minute images, with the Ha data then blended into the HDR composite. The red channel is a blend of the red data and the Ha data. The green channel is made up entirely of the green data. The blue channel is made up entirely of the blue data.

Equipment: RC Optical Systems 14.5 inch Ritchey-Chrétien carbon fiber truss telescope, with ion-milled optics and RCOS field flattener, at about f/9, and an SBIG STX-16803 with internal filter wheel (SBIG filter set), guided by an SBIG AO-X/STX Guider, all riding on a Bisque Paramount ME German Equatorial Mount.

Image Acquisition/Camera Control: Maxim DL, controlled with ACP Expert/Scheduler, working in concert with TheSky X Professional Edition.

Processing: All images calibrated (darks, bias and sky flats), aligned, and combined in Pixinsight. Color combine in Pixinsight. Some finish work (background neutralization, color calibration, deconvolution with BlurXTerminator; noise reduction using NoiseXTerminator, gradient removal, and blending the Ha data with the broadband data) done in Pixinsight; some finish work (LRGB combination, contrast and saturation adjustment) was done in Photoshop CC.

Location: Data acquired remotely from Sierra Remote Observatories, Auberry, California, USA.

Date: Images taken on many nights during April and May of 2026. Image posted October 18, 2026.

Date: Image scale of full-resolution image: 0.56 arcseconds per pixel.

Seeing: Variable; sometimes very good and sometimes not at all good

CCD Chip temperature: -25C

Copyright 2026 Mark de Regt