M66
Messier 66, NGC 3627
24’ x 18’ | 0.3”/px | 4800 × 3600 px
Virgo
RA 11h 10m Dec +12° 59’ | -74°
Messier 66 (M66) is a prominent spiral galaxy located in the constellation Leo, approximately 36 million light-years from Earth. It is the brightest member of the Leo Triplet, a small group of interacting galaxies that also includes Messier 65 and NGC 3628. Classified as an intermediate barred spiral galaxy (type SABb), M66 displays a slightly asymmetric structure, with one spiral arm noticeably more extended than the other—a likely result of gravitational interactions with its neighboring galaxies. This tidal distortion has also contributed to enhanced star formation and visible dust lanes throughout the galaxy. M66 is also notable for its high supernova rate, having hosted three observed supernovae in recent decades (1973R, 1989B, and 2009hd). Its active star formation makes for a dynamic structure. The galaxy is also part of the Arp catalogue under number Arp 371. But this designation is specific to the whole Leo Triplet, not a single galaxy.
source: ChatGPT
Data Acquisition
Data was collected over 7 nights during late March and early April 2025 using a 14” reflector telescope with full-frame camera at the remote observatory in Spain. Data was gathered using standrad LRGB filters. A total of 20 hours of data was combined to create the final image. Both M65 and M66 were captured in the same image and were cropped out as separate images during processing.
Location Remote hosting facility IC Astronomy in Oria, Spain (37°N 2°W)
| Sessions | Moon% | Moon° | Hum% | SQM | T°C | Frames | Exposure |
|---|---|---|---|---|---|---|---|
| 20250328 | 0 | 165 | 50 | 21.5 | 10 | 27 | 1h 21m |
| 20250329 | 1 | 151 | 75 | 21.5 | 8 | 55 | 3h 45m |
| 20250330 | 5 | 151 | 75 | 21.6 | 5 | 118 | 6h 54m |
| 20250331 | 11 | 122 | 40 | 21.6 | 9 | 88 | 5h 28m |
| 20250401 | 20 | 107 | 60 | 21.4 | 10 | 2 | 0h 10m |
| 20250404 | 52 | 64 | 70 | 20.4 | 9 | 11 | 0h 47m |
| 20250418 | 68 | 107 | 75 | 21.5 | 10 | 19 | 1h 35m |
| Total | 320 | 20h 00m |
| Frames | Bin | Gain | Exp.(s) | Frames | Exposure |
|---|---|---|---|---|---|
| Lum | 1 | 0 | 180 | 200 | 10h 00m |
| Red | 1 | 0 | 300 | 40 | 3h 20m |
| Green | 1 | 0 | 300 | 40 | 3h 20m |
| Blue | 1 | 0 | 300 | 40 | 3h 20m |
| Total | 320 | 20h 00m |
Equipment
Telescope
Mount
Camera
Filters
Guiding
Accessoires
Software
Planewave CDK14 (2563mm @ f/7.2), Optec Gemini Rotating focuser
10Micron GM2000HPS, custom pier
Moravian C3-61000 Pro (full frame), cooled to -10 ºC
Chroma 2” LRGB unmounted, Moravian filterwheel L, 7-position
Unguided
Compulab Tensor I-22, Dragonfly, Pegasus Ultimate Powerbox v2
Voyager Advanced, Viking, Mountwizzard4, Astroplanner, PixInsight 1.9.3
Processing
All processing was done in Pixsinsight unless stated otherwise. Default features were enhanced using scripts and tools from RC-Astro, SetiAstro, GraXpert and others. Images were calibrated using 50 Darks, 50 Flats, and 50 Flat-Darks, registered and integrated using WeightedBatchPreProcessing (WBPP). The processing workflow diagram below outlines the steps taken to create the final image.
StarXTerminator had a hard time isolating stars from galaxy in M66, so a mask was created to protect the whole galaxy from SXT. The GAME script was used to make this mask.
Stretching of the RGB image was done using the Colour mode in GHS. This has proven to be a nice way to bring out natural looking colours in the image, without having to add saturation later in during processing.
The combined image containing M65 and M66 was processed all the way to the end, when the individual galaxies were cropped out and rotated 90° counter-clockwise to create a more balanced composition.
The rest of the processing followed a standard processing workflow.
Processing workflow (click to enlarge)
This image has been published on Astrobin
