Lunar Occultation Of Saturn,
16 April 2002
Introduction to lunar occultations.
On 16 April 2002, the Moon occulted Saturn, with disappearance at 20:57 UT and reappearance at 21:27 UT as viewed from Orwell Park Observatory. The Moon was young (phase 15%, waxing) and therefore its illuminated portion did not create too much glare. As a result, Saturn, its rings and its largest satellite, Titan, were easily visible telescopically as the Moon approached. Two members of OASI observed the occultation.
Nigel Evans, East Ipswich
This was my first observation of a lunar occultation of a planet. I tried photographing the event using a 1000 mm telephoto and a Meade ETX 90. To get a regularly spaced set of photos I used the 555-based timer that I used subsequently for solar eclipse photography. It took a couple of minutes for the Moon to completely obscure Saturn and I successfully recorded a pair of sequences, although one camera ran out of film the instant Saturn disappeared.
Mike Whybray, Nacton
Equipment: 114 mm F8 Orion Newtonian reflector with RA motor drive. Eyepiece projection using 20 mm eyepiece and camera adapter onto 35 mm film via Pentax camera body. Adjusted so that Moon fills 75% height of frame. Manual cable release shutter. 400 ASA Fujichrome slide film.
Exposures: Approximately 1 second for all images shown below (best compromise from bracket range of ¼ to 4 seconds). Slides scanned at 800 dpi on Epson 1660 scanner.
Seeing conditions: at start of occultation (20:58 UT) - medium clear but rather turbulent. At end of occultation (21:27 UT) - very turbulent, subject sinking into orange sky glow near horizon.
The four images below are: before occultation; just before occultation; Saturn partially occulted; Saturn partially reappeared.
Nigel Evans, Mike Whybray