This image presents the Milky Way, our Cosmic Home. More specifically, it is a extremely wide field mosaic of the center of our galaxy as seen from Earth. This view, centered on Sagittarius constellation, spans from Aquila to Centaurus, is overhead in the Southern Hemisphere’s cold Winter nights. In this gigantic field over 200 full moons across!

The Milky Way is the galaxy where we all live. It is formed of some 100 billion stars, forming a large disk 100 000 light years in diameter. The Solar System is located about 25000 light years away from its center. It takes 250 million years for our Sun and the solar system to go all the way around the center of the Milky Way. [1] We cannot photograph or see the Milky Way from its outside, but we have a pretty good idea of its general shape and type – a barred spiral. The galactic bulge or center is the brightest part of this image, and in its center, lies Sagittarius A, a strong radio source, likely a supermassive black hole. [2]

The term Milky Way, from latin Via Lactea, is directly related to its appearance in the sky to the naked eye. And it was mostly with the naked eye that humanity experienced and dreamed about our galaxy. The result of many of those dreams and myths are in skies – the constellations. When we look up at them, we see humanity reflection – our own history, culture and beliefs are projected onto the heavens. From the Greek gods, the scientific instruments of the 19th century, the Emu of Australian aborigines, the tapir (“anta”) of Brazilian indigenous people... Carl Sagan’s Cosmos puts it in a beautiful way: “These pictures are not, of course, really in the night sky; we put them there ourselves.” [3] [4]

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This image was quite a challenge! It was captured mostly in July 2016, and the frames were manually framed using a ball head. Some holes were left over and had to be filled in the following nights/weeks. The idea was to make a larger mosaic, from the Southern Milky Way (Vela and Carina), up to Cygnus, possibly extending to Taurus, thus covering all the Milky Way visible from my latitude. Weather has made completing the whole project a challenge as is merging all the panels from different conditions, and I ended up processing the result from July.

Each panel is a single 5’ exposure. Initial processing in Adobe Lightroom; Mosaic merging in Microsoft ICE; Final processing in Adobe Photoshop. There are some seams in the mosaic composition - software matching was not perfect. This was mostly due to different night conditions - slightly different transparency, airglow... Constellation lines labelled in PS using Stellarium as reference. The original image is a whopping 100MP (14900 x 6800px). Here it is presented as a 50% resize.

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 and Time: July 2, 7, 10, 23 and 30, 2016;

Location: MG, Brazil. Rural Skies (Bortle 3-4, SQM ~21.4*calculated)

Camera: Canon EOS T4i and T5 (unmodded), at ISO 800

Lens: Canon 40mm f/2.8 STM, operated at f/3.5

Mount: Sky-Watcher HEQ5, tracking, guided

Guiding: Starguider 50mm Guidescope + ASI120mm + PHD2;

Exposure Detail: 25 panel mosaic; each 1x300s; total 125 minutes

[1] The Milky Way Galaxy – Imagine the Universe! NASA; [2] Wikipedia, Milky Way; [3] Cosmos, Carl Sagan [4] As Constelações Indígenas Brasileiras, Germano Afonso, UFPR;