Arp271
NGC 5426, NGC 5427
16’ x 12’ | 0.3”/px | 3200 × 2400 px
Virgo
RA 14h 03m Dec -06° 01’ | 90°
Arp 271 is a pair of interacting spiral galaxies, NGC 5426 and NGC 5427, located approximately 130 million light-years away in the constellation Virgo. These galaxies are gradually being pulled together by gravity, their spiral arms stretching and distorting as they pass near each other. Their collision triggers intense star formation, especially in the bridge of gas and dust connecting them. The two galaxies are currently separated by a projected distance of about 30,000 to 40,000 light-years, roughly the same width as the Milky Way’s galactic disk. The galaxies are slowly approaching each other. They are likely in their first major encounter, causing tidal distortions and star formation but not yet a full merger. This phase could last 100–200 million years before they swing apart or begin a tighter orbit. Eventually, gravity will bring them together, forming a single elliptical galaxy or a disturbed spiral in 3–5 billion years. Arp 271’s interaction is gentler than the rapid, violent merger of the antennae galaxies NGC 4038 and NGC 4039. Like M51, and its companion, Arp 271 may experience multiple passes before merging.
source: DeepSeek
Data Acquisition
Data was collected over 19 nights during the months May and July 2024 and the months February, March and 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 about 20 hours of data was combined to create the final image.
Location Remote hosting facility IC Astronomy in Oria, Spain (37°N 2°W)
| Sessions | Moon% | Moon° | Hum% | SQM | T°C | Frames | Exposure |
|---|---|---|---|---|---|---|---|
| 20240524 | 94 | 49 | 80 | 20 | 13 | 41 | 3h 25m |
| 20240701 | 20 | 162 | 81 | 21.5 | 17 | 11 | 0h 33m |
| 20240702 | 12 | 149 | 54 | 21.5 | 19 | 12 | 0h 58m |
| 20240703 | 4 | 136 | 51 | 21.6 | 20 | 13 | 0h 55m |
| 20240704 | 2 | 122 | 29 | 21.5 | 21 | 18 | 0h 54m |
| 20240705 | 0 | 109 | 55 | 21.6 | 20 | 17 | 0h 51m |
| 20240708 | 8 | 71 | 84 | 21.5 | 18 | 12 | 0h 40m |
| 20240709 | 17 | 59 | 69 | 21.6 | 20 | 8 | 0h 40m |
| 20240710 | 25 | 47 | 44 | 21.5 | 22 | 7 | 0h 35m |
| 20240711 | 34 | 35 | 30 | 21.5 | 26 | 6 | 0h 30m |
| 20250223 | 18 | 70 | 80 | 21.6 | 4 | 9 | 0h 45m |
| 20250224 | 13 | 83 | 80 | 21.6 | 4 | 2 | 0h 10m |
| 20250324 | 23 | 113 | 75 | 21.5 | 5 | 47 | 2h 59m |
| 20250327 | 2 | 132 | 65 | 21.6 | 8 | 4 | 0h 12m |
| 20250328 | 0 | 147 | 50 | 21.5 | 10 | 51 | 3h 31m |
| 20250330 | 5 | 171 | 75 | 21.6 | 5 | 4 | 0h 14m |
| 20250331 | 11 | 165 | 40 | 21.6 | 9 | 4 | 0h 12m |
| 20250401 | 20 | 151 | 60 | 21.4 | 10 | 32 | 1h 36m |
| 20250404 | 52 | 108 | 70 | 20.4 | 9 | 11 | 0h 33m |
| Total | 309 | 20h 13m |
| Frames | Bin | Gain | Exp.(s) | Frames | Exposure |
|---|---|---|---|---|---|
| Lum | 1 | 0 | 180 | 166 | 8h 18m |
| Red | 1 | 0 | 300 | 50 | 4h 10m |
| Green | 1 | 0 | 300 | 50 | 4h 10m |
| Blue | 1 | 0 | 300 | 43 | 3h 35m |
| Total | 309 | 20h 13m |
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.
The data was collected during two different periods, almost one year apart. Therefore calibration of the 2024 data was done with a different set of Flats and Darks than calibration of the 2025 data. The WBPP script was run three times, one time for each of the sets of calibrations, and a third time for registration, normalisation and integration.
The target is quite small compared to the full frame, so as a final step in the processing a serious crop was applied. For aesthetic reasons, the image was also rotated 90°. For some reason the image solver could not resolve the final cropped image, so the astrometry data above are based on estimates of the full frame image.
The rest of the processing followed a standard processing workflow.
Processing workflow (click to enlarge)
This image has been published on Astrobin
