Auroral Glow and Nearby Galaxies

 I was out in the early evening to take a few quick constellation photos.  The sky brightness was once again rather poor (sqml=21.15) for this area.  The previous night I had measured sqml=21.25 and could see the familiar green tint of airglow in the out-of-camera images.  Here is one of the first images I shot last night, after processing:

Olympus E-M1iii + Sigma 30mm f/1.4 + softon filter.

There are two galaxies in this image marked by white circles: the famous Andromeda Galaxy (M31), at the top, and the Triangulum Galaxy (M33), near the middle.  Triangulum is the constellation name associated with the three stars that form a narrow triangle in the lower middle of the image

The red glow in the bottom left of the image bothered me.  I thought perhaps I had left my headlamp on during the exposure, or there was glow from the cabin lights behind me.  I went out to reshoot the image a half hour later with this region higher in the sky.  I also added a shot of the constellation Auriga rising over the northern ridgeline.  That shot was a big surprise:

E-M1iii + Sigma 30mm f/1.4 + softon filter.  ISO 1600, 60 s.

The earth was recently hit by a CME (Coronal Mass Ejection) from the sun causing auroral displays in the north.  Although it was not obvious to the naked eye, that pink auroral glow has extended down into southern Colorado and shows up intensely in photographs. 

 My original purpose for being out last night was to get a wide-angle shot showing the relative locations of the Andromeda Galaxy (M31) and the Triangulum Galaxy (M33). The Triangulum Galaxy is the third largest galaxy in our Local Group (after M31 and our galaxy).  It is 2.8 million ly distant and is just visible to the naked eye in a sufficiently dark sky (not the case last night) if you have good eyes (not me).  If you do manage to see it you will be gazing at the most distant object possible to see without optical aid.  The Andromeda Galaxy is a bit closer at 2.5 million ly distant and is much brighter and easier to locate in a dark sky.

Triangulum Galaxy.  E-P5 + Rokinon 135mm f/2.  ISO 1600, 60 s.