Feb 2014

Winter Milky Way from South Carolina

Hi Everyone,
My wife and I are on a holiday in South Carolina this week and as it turns out, the spot we picked to catch some sun and warmth is not bad for star-gazing. We are on the NE side of Harbor Island between Charleston SC and Savannah GA. Our condo has a nice dark beachfront facing the Atlantic Ocean.

The image below is the view of the Winter MW I took on the first night (and only good one so far). The waxing gibbous moon spoiled the show later in the evening but it provided for a nice moonrise beneath reddish clouds. The moon image looks a bit different, because it is a composite image. Exposing for moon features requires a very short exposure and the red sky needs longer. So I pasted the moon image onto the sky image. It is definitely an interesting view, if not quite real.



Light Pillars of Winter

Light pillars occur generally in winter, when ice crystals, the flat hexagonal kind, drift downwards slowly above a light source. A concentrated source can create a narrow pillar as reflections are produced by the undersides of the crystals. The diagram below shows the situation pretty clearly.

Coloured beams are produced by coloured lights, yellow being common since many streetlights are sodium lights. Aaron’s photo below shows an interesting combination of colours, including green which I have never seen before. In my image the set of three broad light blue rays are from the car dealers on the Sunset Strip. Those above my house are from lights generally in Owen Sound, streetlights being the brightest. It is not difficult to see from where the greatest amount of light pollution comes, nor who is spending the most on lighting up the night sky. The last figure from IDA is about 100 Billion dollars world-wide is wasted around the globe!

Once more full-cutoff fixtures appear, it will be interesting to see if pillars will be created since these fixtures send no light upwards. If dark-sky enthusiasts get their wish and all light sources are shielded (unlikely), the light pillar phenomena may become much scarcer. Perhaps we should enjoy it while it lasts. In any case, the sun and moon will still be around and light pillars produced by these are common and easily photographed.


Image above: OS light pillars above my house Jan 24 -one of the very few clear nights in January. Photo by John H. Canon 60Da. Exp = 6 s, 10 mm lens, f/2.8 ISO 1600

Image below: Aaron Top, Canon 60Da?, 17 mm lens, f/4, 35 s exp. ISO 800


Hope you see some soon (and take images!) -John H.