Daylight Moon and Regulus

On the 23rd May 2007, from much of the UK the Moon would be seen to move in front of (occult) the star Regulus (alpha Leonis, mag. +1.34) during the hours of bright daylight.

Unfortunately From my location in Selsey, on the UK's south coast, the Moon would pass a fraction above Regulus and no occultation would be seen. As it happened despite a beautifully clear morning, the clouds rolled over the sky and obscured the closest approach. However, I did manage to capture some before and after shots as well as some overview shots of the scene taken after the event.

When first looking for Regulus, I was expecting something of a challenge to be able to pick it out. The Moon was the key to the observation because it provided a target to focus on and a reference point in an otherwise featureless blue sky.

As it turned out, Regulus actually appeared quite bright and intense. Using an Astronomik red filter darkened the sky (removed the blue component) and improved the view considerably.

Shortly after imaging the beginning of the close approach, the clouds rolled in. Some time after close approach, they dissipated once again. After capturing a few shots of the separation, I decided to try and use my DSLR camera with my small 80mm f/7.5 refractor. I was pleasantly surprised to find that Regulus was an easy visual target through this scope. To see a pinpoint star against a light blue sky backdrop is quite something. This was my first ever sighting of a star (other than the Sun!) during the day and an awesome sight that I will not forget for a long time.

Update: a joint project with my good friend Anthony Ayiomamitis from Greece has given us the distance to the Moon...