Flights to sunny spots

Astronomers face a number of factors that can influence our view or image of the stars and planets even in a “clear” sky. Some of them are natural effects, like clouds or the light from a bright Moon. Moisture in the atmosphere can also play a big part and is the reason why the stars “twinkle” in the sky. Of course the effect is worse for objects that are close to the horizon and Astronomers use the word “seeing” to describe the quality of the view.

Then we have man-made effects – the most obvious being light pollution which is always the subject of much discussion in the Astronomy community. To an extent light pollution can be avoided by moving to a dark site or removed using specially designed filters at the eyepiece or camera. However, one effect which is harder to control comes from aircraft traffic which gets worse close to any major airport. The condensation trails from aircraft spread out at high altitude and can affect the seeing much the same as clouds. But also the aircraft themselves can cross the field of view and ruin an image. Particularly when taking wide-field pictures at night when the navigation lights appear as a series of parallel dots.

But occasionally you get an interesting image of a aircraft, like this one captured against the Sun using a Canon EOS450 camera at prime focus of an ETX125. The telescope was used in conjunction with a solar filter kindly lent to me by club member Chris Thayer. This picture shows both the aircraft and the vapour trails. Top right there are even two sunspots which were the real reason for the image in the first place!

It goes without saying that pointing any telescope, no matter how small, at the Sun can cause irrevocable damage to the eye and must not be attempted without specialist equipment and guidance.

Over Christmas I failed to get a similar picture of Santa with his sleigh and reindeer.  I was interested to see how Rudolph’s nose would look on a long exposure and curious as to whether reindeer leave a vapour trail………but there’s always next year!