M89
NGC 4552
38’ x 25’ | 0.8”/px | 3000 × 2000 px
Virgo
RA 12h 35m Dec +12° 29’ | -114°
Messier 89 (M89), also known as NGC 4552, is an elliptical galaxy located in the Virgo Cluster, within the constellation Virgo. It was discovered by Charles Messier on March 18, 1781. M89 is notable for its nearly perfect spherical shape, which is unusual for elliptical galaxies that typically appear as elongated ellipsoids. This spherical appearance may be due to its orientation relative to Earth. M89 is approximately 50 to 55 million light-years away from Earth and has an apparent magnitude of about 9.8 to 10.73. The galaxy contains around 100 billion stars and over 2,000 globular clusters. The galaxy is surrounded by a structure of gas and dust extending up to 150,000 light-years, and it features jets of heated particles stretching about 100,000 light-years outwards. This structure suggests that M89 may have been an active quasar or radio galaxy in the past. Additionally, M89 is surrounded by an extensive system of shells and plumes, which may have been caused by past mergers with smaller galaxies.
source: Mistral
Data Acquisition
Data was collected over 3 nights, during early April 2025 using a 130mm refractor telescope with full-frame camera from the backyard in The Netherlands. Data was collected using standrad LRGB filters. A total of about 18 hours of data was combined to create the final image. Both M87 and M89 were captured in the same image and were cropped out as separate images during processing.
Location Backyard Observatory in Groningen, The Netherlands (53°N 6°E)
| Sessions | Moon% | Moon° | Hum% | SQM | T°C | Frames | Exposure |
|---|---|---|---|---|---|---|---|
| 20250402 | 30 | 107 | 70 | 19.5 | 8 | 114 | 6h 50m |
| 20250403 | 37 | 94 | 70 | 19.6 | 8 | 100 | 6h 36m |
| 20250404 | 46 | 80 | 80 | 19.3 | 6 | 88 | 5h 12m |
| Total | 302 | 18h 38m |
| Frames | Bin | Gain | Exp.(s) | Frames | Exposure |
|---|---|---|---|---|---|
| Lum | 1 | 0 | 180 | 196 | 9h 48m |
| Red | 1 | 0 | 300 | 40 | 3h 20m |
| Green | 1 | 0 | 300 | 32 | 2h 40m |
| Blue | 1 | 0 | 300 | 34 | 2h 50m |
| Total | 302 | 18h 38m |
Equipment
Telescope
Mount
Camera
Filters
Guiding
Accessoires
Software
Takahashi TOA-130, FL67 flattener, Pegasus Astro Motor Focus kit v2
10Micron GM1000HPS, EuroEMC S130 pier
ZWO ASI6200MM Pro, cooled to -15 ºC
Antlia 2” unmounted LRGB V-Pro, ZWO EFW 7-position
Unguided
Fitlet3, Pegasus Ultimate Powerbox v2, DeepSkyDad Flatpanel FT1 (30cm), Pegasus Uranus
Linux Mint, KStars/Ekos, INDI Library, Mountwizzard4, 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, CosmicPhotons 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.
The luminance stack had some artefacts in the background that had not been corrected fully by the flats. To remove them, stars were temporarily removed and background was cleaned up using the CloneStamp tool. Then the stars were put back in again. After the processing was complete, I learned about the use of synthetic flats, which would have been an ideal method to apply here, but we will leave that for some other time.
The stretching of this image was a bit different than normal. This had mostly to do with the desire to bring out a plasma-jet in M87. See the processing section of M87 for specifics.
The rest of the processing followed a standard processing workflow.
Processing workflow (click to enlarge)
This image has been published on Astrobin.
