October 5, 2013 – The Amazing Sky

The stars of Andromeda the Princess highlight the autumn sky.

Here’s an image from last night, October 4, that frames all of the constellation of Andromeda, now high in the northern autumn sky. A trio of coloured stars arcs across the centre of the image, forming the main pattern in Andromeda. In Greek legend she was the daughter of Queen Cassiopeia and was rescued by Perseus from the devouring jaws of Cetus the Sea Monster.

Above the centre star lies the constellation’s most famous feature, the Andromeda Galaxy, shining at us from 2.5 million light years away. It is the most distant object easily visible to the unaided eye.

An equal distance below the centre star of Andromeda you can see another smaller fuzzy spot. That’s the Pinwheel or Triangulum Galaxy, a dwarf spiral 2.8 million light years away, but also a member of the Local Group of galaxies that contains our Milky Way and Andromeda as its two main members.

At left, just below centre, is a large open cluster of stars, NGC 752, easily visible to the naked eye.

For this shot, as I do for most constellation portraits, I used Photoshop to layer in a shot taken through a diffusion filter (the Kenko Softon A) on top of a stack of shots taken without the filter. This allows me to add the enhanced glows around stars to bring out their colours, and to do so in a controlled fashion by varying the opacity of the filtered view. Shooting on a night with high haze or cirrus clouds has the same end effect but that’s hardly a reliable way to take constellation images. Combining filtered and unfiltered views works great, and gives the “look” made popular years ago by Japanese astrophotographer Akira Fuji.