I love planetary conjunctions and watching the Solar System in action as the planets follow their orbits across the sky. I learned a long time ago that following planets regularly in the sky and watching their constant movements and relative sizes provides a deeper sense of understanding of our cosmic neighbourhood.
So it was frustrating to miss the unusually close conjunction (on the evening of 1st January 2017) of Neptune and Mars – due to eight days of thick cloud here in SW Sydney. The apparent separation between them that night was a mere five arc-minutes – and would have made a fine view in my telescope.
However, I didn’t get a viewing opportunity until five days later, when the gap between the pair had widened to 3.75°. This was much larger than the field of view in my telescope, so I made my first ever attempt to image Neptune with a camera on a tripod – and this was the result:
Hydor is also known as Lambda Aquarii, a magnitude +3.75 star. Distance 390 light years.
Venus was magnitude -4.4, distance 0.73 AU.
Mars was magnitude +0.9, distance 1.68 AU
Neptune was magnitude +7.9, distance 30.52 AU
One light year = 63,241 AU.
The faintest stars in these shots were about magnitude +9.5
All images © R.Powell