NGC253 Sculptor Galaxy ("Silver Coin")


This photography was taken in 3 sessions, along approximately one year, using a Canon 600D modified camera and a 200mm F4 reflector telescope, from San Antonio de Areco, Buenos Aires, Argentina.
It is composed by 71 individual frames, with a total integration time of about 6 hours.

NGC253 (Sculptor Galaxy, also known as “Silver Coin Galaxy”) is a barred spiral galaxy at the austral constellation Sculptor, with an estimated distance of approximately 12 million light-years from Earth.
This galaxy shows a large quantity of interstellar dust on its arms and has a high rate of stars’creation (starbust).

It is the most brilliant member of the Sculptor Group, the galaxy cluster closer to the Local Group where our galaxy belongs.
This group is composed by other members, like NGC247. Since the gravitational interaction among the group members is relatively low, is believed it that it is actually a “filament” (a previous step to a group formation).

Previously was believed that some galaxies such as the irregular NGC55 and the spiral galaxy NGC300 were also part of this group, but new research shows that both galaxies (gravitationally tied between them) are really in the foreground.

This is the second or third galaxy with the highest absolute bright among the closest galaxies, being only surpassed by the Sombrero Galaxy and probably Andromeda. It is also one of the apparently bigger and brightest galaxies from our point of view.

In the annotated image, it is possible see around 50 galaxies on the background sky.


Technical Data

Acquisition site San Antonio de Areco, Buenos Aires, Argentina
Acquisition dates 10-17-2015 (x29)
09-24-2016 (x25)
11-5-2016 (x17)
Instrument Newton GSO F4 200 with GPU coma corrector.
Mount Sky-Watcher NEQ6, managed by EQmod
Guide Off-Axis, with Lodestar camera
Camera Modified Canon 600D/T3i
No IR Filter (Full Spectrum mod, using Astronomik MC Clear)
Refrigerated (regulated temperature)
Camera sensor temperature 0°C (on-sensor measured and regulated)
Filter Astronomik Clip CLS CCD
Integration 71 x 5 minutes subframes - ISO 1600
Total integration time: 5 hs 55 minutes
Calibration 49 flats, 300 bias, 53 darks.
Resolution 1.1 arcsec/pixel
787 mm actual focal, 4.2 um x 4.2 um pixels
Native size 5202 x 3465 pixels
Cropped size 4440 x 2975 pixels
FOV 81’ x 54’
Image center coordinates RA: 00h 47min 32sec
Dec: -25° 17' 10"
Rotation: -170°
Process PixInsight 1.8