This is the beautiful galaxy Centaurus A. Is is 11 million light-years away, the closest active galaxy to planet Earth. Spanning about 60,000 light-years, the peculiar elliptical galaxy is also known as NGC 5128. Centaurus A is apparently the result of a collision of two otherwise normal galaxies resulting in a fantastic jumble of star clusters and imposing dark dust lanes. Near the galaxy's center, left over cosmic debris is steadily being consumed by a central black hole with a billion times the mass of the Sun. As in other active galaxies, that process likely generates the radio, X-ray, and gamma-ray energy radiated by Centaurus A. [1] NGC 5128 was first identified in 1826 by James Dunlop. The name "A" is given by astronomers as the brighter radio source in the constellation Centaurus.

In the wonderful book "A View of the Universe", David Malin writes: "[Centaurus A] had long been labelled as peculiar, or at least noteworthy, since it was first sketched by James Dunlop [...] in the 1820s. [...] The dark lane is ahuge dusty curtain which obscures, dims and reddens the light of stars behind it. The name 'Centaurus A' indicates that this most unusual object is the brightest radio source in that constellation. It was one of the first radio sources to be positively identified with an optical object [...] in the 1950s." [2] Malin's usage of unsharp masking has revealed fainter, then unknown shell-like structures in the halo, from a plate taken by John Graham with CTIO 4m telescope. [3]

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This image was captured with my new telescope, on its first fully working night under the stars! I'm very happy to use this Newtonian Astrograph for DSO imaging. The full story is on my previous Omega Centauri image, but the design is a 150mm f/5 Newtonian, made by Sandro Coletti and other Brazilian ATM's, used with TS-Optics MaxField Coma Corrector. As the telescope is pretty much custom made, there is still much to be optimized and adjusted. Furthermore, @ 710mm FL, tracking, guiding, wind and seeing become more of a concern (compared to my usual ~135mm widefields).

In this image I was extremely happy to capture the faint (and I say extremely faint!) halo features, despite the short 1h30 integration. I still plan on adding some 5+ h of data to better capture it. The halo has a wonderful history and I recommend checking the inspirational works by Olsen, Neyer, and Malin [4].

Constructive criticism, comments and suggestions are more than welcome in the comments section. Thank you for taking your time to look at this image.

Date: March 30, 2019

Location: MG, Brazil. Rural Skies (Bortle 2-3-4, calculated SQM ~21.6)

Camera: Canon EOS T5/1200D (modded), at ISO 1600

Optics: 150/750mm ATM Newtonian Telescope (optics by Sandro Coletti) + TS-Optics MaxField 2" Coma Corrector

Mount: Sky-Watcher HEQ5, tracking, guided (~0.9" RMS)

Exposure Detail: 28x180s = Total 84'

[1] APOD 2017/03/09; [2] [3] A View of the Universe, David Malin, pp. 213-214. Cambridge University Press, 1993. [4] Olsen: rolfolsenastrophotography.com/Astrophotography/Centaurus-A-Extreme-Deep-Field ; Neyer: http://www.starpointing.com/ccd/ngc5128.html