NGC 1055 is a spiral galaxy, seen almost edge-on, located about 50 million light years from us. It has a very large central bulge, and a very prominent set of dust lanes running through the edge of the galaxy. NGC 1055 is is somewhat misshapen, perhaps due to its gravitational interaction with it's immediate neighbor, M77, which is just outside of this field. These are part of a small galaxy group that also includes NGC 1073.

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 uneven nature of the halo around the galaxy is thought to have been caused by gravitational interactions with other galaxies (including M77), and collisions with smaller satellite galaxies, all leaving tidal tails and tidal shells.

The yellow/red magnitude 6.7 star below the galaxy made processing a bit of a challenge, especially combined with the magnitude 7.6 blue star to its right.

NGC 1055 is a large galaxy, with a diameter of about 114,000 light years (about the same as our Milky Way).

The entire field of the uncropped version of the 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!

Technical Information:

LRGB: 480:240:210:260 (a total of almost 20 hours of exposures); here's a chart showing the various subexposures I used in the image:

Luminance: 28 fifteen-minute, and 20 three-minute
Red: 16 fifteen-minute
Green: 14 fifteen-minute
Blue: 13 twenty-minute

I also took 20 twenty-minute exposures through an Ha filter, but did not end up using them since they added nothing.

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 SBIGSTX 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) 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 December of 2025. Image posted June 8, 2026.

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

Seeing: Varied; sometimes good and sometimes bad

CCD Chip temperature: -25C

Copyright 2025, 2026 Mark de Regt