The photo shows a single shot made with a tracking mount of the entire Andromeda constellation rising above a puddle of acid water from Achada do Gamo. Andromeda Galaxy M31 stands very well visible and aligned between two chimneys from the century old mine of São Domingos, in Dark Sky® Alqueva – Mértola, highlighted against a faint greenish background from a thin band of airglow. With approximately 4 times the angular size of the full moon as seen from Earth, the great spiral galaxy Andromeda is at a mere 2.5 million light-years distant from us, being the closest large spiral to our own Milky Way. In really dark places we can clearly distinguish this naked eye galaxy, but how to find it? Start to identify the star Alpheratz, as the constellation Andromeda begins here, then follow down two stars and we will end up on Mirach. You should see two stars stacked one on top of each other, are they Mirach and Mu Andromedae. If you draw a line through the two stars and extend it past Mu Andromedae star, you should run into the Andromeda galaxy, which is located at about the same distance that separates this last two stars mentioned, being Mu Andromedae much dimmer than Mirach star. Very close to Andromeda galaxy is also visible an even week star called Nu Andromedae. The annotated version that can be found below, also shows galaxy M33 and the well known double cluster in Perseus.